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Shed roof truss system: device rules and analysis of typical options. Shed roof rafter system: use a calculator to calculate the rafter system How to attach rafters to shed roof beams

For the construction of small buildings and houses, there is no need for a roof of a complex configuration. As a design solution, a shed roof truss system can be adopted. In this case, the scheme is simplified, but some nuances appear.

Advantages and features of a single-slope system

The advantages include:

simple calculation;
reduction in the number of nodes and connections;
simplification of installation;
reducing the cost of wood;
maintainability.

Shed roof is resistant to external negative conditions, inexpensive and easy to install

the need to erect high longitudinal walls of the building or special frames;
the difficulty of using the under-roof space as an attic room;
it is necessary to locate a house or building on the site so that in most cases the wind blows on the high wall of the building (you need to familiarize yourself with the wind rose of the construction area);
the angle of inclination is taken depending on the coating material used.

The scheme includes the following main elements:

two Mauerlat;
rafter legs.

The design of the truss system of a shed roof

For large spans, you will need to do-it-yourself additional elements that unfasten the load-bearing beams and increase their bearing capacity:

All elements are made of coniferous wood of the first or second grade. In order to choose the most suitable material, you need to pay attention to the following points:

felling place (it is better to choose the northern regions);
felling time (a tree cut down at the end of winter - beginning of spring will be stronger).

System calculation

Before proceeding with the assembly of the structure with your own hands, it is necessary to make a calculation and correctly select the section of all elements.

Roofing is a responsible process in which mistakes cannot be made.

Depending on the width of the building and the required section of the rafter leg for the projected span, a constructive solution for the truss system is selected.

Calculation of the length of the rafter legs

Section selection

When building a house by professional builders according to a pre-prepared project, a calculation is performed for two limit states, which determines the height and width of the supporting beams according to two requirements:

rigidity;
strength.

Dependence of the structure on the span

When building a private house with your own hands, the calculation can not be performed, but it is necessary to take into account the recommendations depending on the span. The rafters on a shed roof are always layered.

Span up to 4.5 meters. The scheme involves the use of solid rafter legs, without unfastening with struts or racks. It is also convenient to use if an attic device is planned: it allows you to increase free space due to the absence of intermediate supports. The recommended section of the rafters at a step of 0.6 m is 50x150 mm, for a step of 1.1 m an increase to 75x175 mm will be required.
Span up to 6 meters. In this case, it all depends on the angle of inclination and span. In some cases, the standard length of a board or beam is enough - 6 m. With a large angle of inclination and a span close to 6 m, it will be necessary to join the rafter legs along the length. As an additional support, struts (rafter legs) are provided. At the junction of the brace to the rafter, the leg is joined along the length. The recommended section at a step of 0.6 m is 50x200 mm, at a step of 1.1 m - 100x200 mm.
span over 6 meters. In this case, you need to make intermediate racks that will take on part of the load and reduce the sagging of the beam. Correctly install the supports so that each span of the rafter leg is less than 6 meters. The calculation in this case is performed as for a multi-span beam, taking into account intermediate supports. When building with your own hands, the section is taken in the same way as for a span of up to 6 m (previous paragraph). In this case, all rafters are composite.

If it is planned to lay insulation between the rafters with your own hands (warm attic, attic), then the calculation takes into account the minimum height of the beams.

The thickness of the insulation should not exceed the height of the rafter legs for polyurethane foam, polystyrene foam and extruded polystyrene foam.

If it is planned to lay mineral wool, then an additional 5 cm ventilation gap is taken into account. It is partly provided by the load-bearing beams, and partly by the counter-lattice, which is mounted on top of them.

Beam pitch selection

The step of the rafter legs depends on the following factors:

Rafter section table depending on their length and pitch

type of thermal insulation material;

the presence of skylights.

In the first case, the dependence is inversely proportional. The design of a shed roof involves a decrease in the pitch of the rafters with an increase in span or load. For the type of insulation, the following recommended values \u200b\u200bof the distance between the rafters in the light (in cleanliness) can be given:

polystyrene and extruded polystyrene foam - 0.6 m;
mineral wool - 0.58m;
polyurethane foam - the step does not depend on the insulation.

When designing an attic and using roof windows as light sources, it will be necessary to ensure that the rafter pitch is 4-6 cm more than the width of the window at their installation sites.

Tilt angle

Depending on the type of roofing used, it is allowed to take different angles of inclination of the roof slope. Below are the values for the most common materials. It is important to remember that the steeper the slope, the less the likelihood of leakage and the load on the elements, but this complicates the construction and requires the construction of a high longitudinal wall.

Ceramic tiles. The optimal angle of inclination is 30-45 degrees, the permissible one is 12-65 degrees.
Bituminous (soft) tile. Optimal - 20-45 degrees, permissible - from 6 degrees.
Metal tile. Optimal - 20-45 degrees, permissible - from 12 degrees.
Galvanized roofing steel. Permissible - from 14 degrees.
Slate. Permissible - 6-27 degrees.

The smaller the angle of inclination, the lower the consumption of materials for construction, but this increases the load on the roof and the likelihood of leaks.

Work order

After the calculation is completed, proceed to the purchase of material and assembly of the structure.

Treatment of elements with an antiseptic. Can be done after installation in the design position, but if you plan to store wood, you need to process immediately after purchase.
Waterproofing of places of contact of materials with different properties. In the place where the Mauerlats are laid on a brick or concrete wall, a layer of roofing material, linocrom or hydroisol must be laid.
Laying the Mauerlat and fixing it to the wall. Can be performed on wire, staples, studs, anchor bolts.
Laying rafter legs. Fixing them to the Mauerlat. Can be fastened using staples, nails or corners on self-tapping screws.
Installation of waterproofing and battens.
Insulation lining.
Roof covering.
Installation of the lower crate and ceiling lining.

It is important to correctly select the scheme of a shed roof, the sections of the elements, the pitch of the rafters and the angle of inclination. Compliance with the technology of doing the work with your own hands will ensure the reliability and durability of the structure.

Shed roof truss system: scheme

Shed roof construction is easier than other foundations. We will tell you how to calculate and install a shed roof truss system

Shed roof truss system: device and fastening

The shed roof truss system has a number of advantages that make it a good choice for installation on auxiliary buildings, garages, extensions to the main building.

Benefits of a pitched roof

The device of a shed roof on buildings of various types is beneficial due to a number of factors:

low weight of the structure;
low cost of construction;
simple installation technology;
the possibility of using a wide range of structural and roofing materials;
ease of installation of the drainage system, chimney.

A roof structure with a single slope can be used in the construction of a house to implement original design ideas. In addition, this is a favorite version of the roof frame for outbuildings, garages, baths, sheds and verandas.

When building a detached garage made of bricks, concrete slabs or a metal structure can serve as the basis for the installation of roofing material. But no less often a truss system of wooden elements is erected. Calculation of rafters for small buildings can be done independently, in difficult cases it is recommended to contact professionals.

Rafters: design calculation and material preparation

The scheme for the construction of a shed roof is extremely simple: the rafters cover the span between the end walls of the building. The angle of inclination of the slope is determined by the difference in the height of the walls. Two methods can be used to achieve this height difference.:

the laying of one of the opposite load-bearing walls is carried out to a great height;
special supports are mounted on one of the walls, on which a run is laid to support the upper ends of the rafters.

The first option is most suitable for the construction of a structure from piece materials. The second method allows you to save building materials from which the walls are built.

A roof structure with one slope should have a slope of no more than 50-60 °. The optimal value is considered to be an angle of 18-35 °, but specific parameters should be chosen taking into account various factors. The rafter system must withstand its own weight and high external loads - wind and snow. The intensity of the loads directly depends on the angle of the slopes. In addition, you should pay attention at what values it is possible to install the selected roofing material.

The pitch of the rafters also affects the reliability of the roof. The smaller the step, the higher the calculated load that the roof can withstand. But if the installation step of the rafter legs is unreasonably small, this leads to an increase in the weight of the structure, and, accordingly, the load on the walls and foundation of the building. Too large a pitch of the rafters will not allow you to create a roof that is resistant to external influences.

The design calculation can be done manually, but it is more convenient to do this using a special program. The developed project should reflect not only the pitch, dimensions and sections of the elements, but also the schemes for the execution of the roof frame nodes.

Shed roof rafters for small spans are made of boards or beams. If the span exceeds 4.5 meters, you may need to install elongated rafter legs.

The timber and boards for the manufacture of the truss system of a garage or other structure must be well dried and not have damage that affects the strength characteristics. Before installation, prepared wooden elements must be treated with a fire-retardant compound to protect the frame from accidental fire and extend its service life.

Garage roof rafter installation scheme

The rafter system of the garage roof during the construction of a shed structure may vary depending on the characteristics of the building. On a small structure, it is enough to simply lay the rafters, resting them on the upper part of the opposite walls, lined with bricks or blocks. If it is planned to build a garage with an attic, then in this case it is necessary to lay beams across the span (step - 1-1.5 m), which will serve as the basis for the floor. The rafters, as in the first case, are attached to opposite walls, but at the same time they are additionally reinforced with struts - this allows you to provide the necessary rigidity of the garage roof frame.

If the box of the structure is made of brick, the laying of the ends of the beams and rafter legs of the shed roof of the garage can be carried out in special nests provided in the walls. In this case, the beams are fastened to long walls, and the rafters to the end walls. The high wall should be the wall with the garage door. Waterproofing made of rolled bitumen-containing material is preliminarily laid in the nests.

Wooden rafters for a shed roof can be mounted directly on the walls of the structure if a small span is covered and the rafter spacing is sufficient to receive and distribute the load fairly evenly. In other cases, the rafter legs are attached to the Mauerlat.

The requirements for the Mauerlat are quite simple: it must be strong, durable, firmly fixed on a wall erected from piece building materials. Theoretically, the rafters should be fastened to the Mauerlat mounted on the reinforced belt of the wall. But since the garage belongs to buildings with low loads, the support beam for the rafters can be laid directly on the upper edge of the wall and fixed to anchors and rolled wire embedded in the masonry. Mauerlat requires reliable waterproofing made of rolled materials.

The armored belt of the wall under the shed roof is made of reinforced concrete. For its arrangement, it is necessary to make a plank formwork, fix the reinforcement in it and install the studs. The height of the embedded fasteners should allow in the future to lay a Mauerlat beam with pre-drilled holes for the studs on top of the monolithic beam and fasten it with nuts equipped with wide washers.

If a garage or other building is built from timber or logs, the function of the Mauerlat is performed by the upper trim of the log house. The installation step of the rafter legs on a shed roof is most often 60-70 cm - this parameter makes it possible to use almost any piece or roll material for the roof, provided that the appropriate type of crate is installed.

In order for the rafter system to make it possible to equip a roof that can protect building structures from the effects of precipitation, the rafter legs must protrude 30-40 cm beyond the edge of the wall, forming an overhang.

Installation of the extension roof

A residential or commercial extension is a building adjacent to the main building. Most often, a shed roof is erected over it, adjacent to the wall of the main building or its roof. The fastening of the rafters of the shed roof of the extension differs to some extent from the installation of the roof frame on a separate structure. The main difference concerns the installation of the upper part of the rafters - the lower ends of the rafter legs are attached to the Mauerlat or a special support using standard methods.

Before erecting a shed roof extension, it is important to determine the required angle of inclination of the slope. In accordance with the obtained value of the required difference between the front wall of the extension and the back wall, a wooden structure is mounted from a beam with a cross section of at least 150 × 150 mm. Particular attention must be paid to the connection of the frame for the rafters with the wall of the main building.

Rigid fastening is not recommended, since adjacent buildings may have different shrinkage rates, which over time will lead to the formation of cracks in the walls. The device of such a bundle usually involves the use of an elastic layer between the support beam for the rafters and the wall. The beam can be laid on columnar supports or a frame made of timber. The gap of 2-3 cm between the beam and the wall (expansion joint) should be filled with polyurethane foam or other elastic material with low thermal conductivity. It is allowed to fasten the beam to the wall by means of anchors.

If it is required that the roof of the extension adjoins not to the wall, but to the roof of the main building, it is advisable to think in advance what technology will be used to install the truss system. To ensure maximum reliability of the shed roof of a new building, it is recommended to completely dismantle the adjacent roof slope of the main building in order to install new rafter legs from the ridge of the main roof to the extension Mauerlat. It is necessary to provide for the release of the rafters beyond the plane of the extension wall for the installation of a cornice. Another option involves connecting the rafters of the extension to the rafters of the main roof at a certain distance from its ridge. In this case, the device for adjoining roofs requires the dismantling of only part of the slope of the main roof.

When choosing the angle of inclination of the roof of the extension, you should pay attention to the following points:

the greater the angle of inclination of the rafters, the less the danger of accumulation of rainwater or snow mass that has “moved out” from the main roof;
the rafters of an extension located on the south side may have a smaller slope than that of a similar structure on the north side, because. the sun promotes intensive evaporation of moisture.

Wooden rafters for a shed roof are sensitive to moisture. The places where the rafter legs adjoin the wall or main roof should be carefully sealed - for this purpose, a roof apron is installed.

Shed roof truss system: how to install, fastening, device

The device and fastening of the truss system for a shed roof. Design, installation and selection of rafter pitch for a shed roof of a house, garage or extension.

How to install a shed roof truss system - rafter installation guide

Among the wide variety of roof types, the shed roof is considered the simplest and most economical. The design requires a minimum amount of materials with a simple installation technology. The construction of a shed roof can be a good lesson for a novice roofer. But success, even in a simple matter, can only be achieved if strict technological requirements are observed. For high-quality performance of work and reliability of the roof, it is necessary to know the features and basic rules for installing the truss system of a pitched roof.

Roofs with one slope for low-rise construction

Shed roofs are most often used in the construction of small buildings, such as terraces, garages, verandas and domestic premises. On residential buildings, such a roof can be seen very rarely, most often these are buildings in the Art Nouveau and high-tech style.

The attic space under a shed type roof has a small area, so it is very difficult to equip a room in this space. In this case, the question may arise whether it is necessary to make an overlap between the attic and the main building. If the overlap is not advisable, then you can replace it with struts and rafter legs. This option is very often used by builders in practice.

In general, the rafter system of a shed roof is similar to an overlap laid at an angle or half of a layered system, that is, it is a structural element of the structure. For its construction, layered rafter legs are needed. In other words, the shed roof frame is constructed from rafters, which have a strong support at the top and bottom.

The following can be used as support for the rafters of a pitched roof:

Two load-bearing walls. At the same time, a double Mauerlat, an upper beam or a log of a wooden structure, a reinforced concrete belt, which must be arranged during the construction of walls, can become an intermediary between the elements of the truss system and the walls.
One load-bearing wall and opposite supports. This method is used in the construction of outbuildings and sheds. The support of the upper heel of the rafter leg falls on a steel bracket, which is screwed to the load-bearing wall, or on a nest selected in the load-bearing wall. At the bottom of the rafter rests on the strapping of the supporting pillars.
Two rows of supports. The support for the upper and lower heels of the rafter legs is the binding of the support posts. In this case, supports can be used as elements for attaching the skin and forming the frame.

In private construction, small buildings are most often found, so it’s worth taking a closer look at the design of the shed roof truss system. If you understand this issue, then you can do all the work with your own hands, making the necessary additions and changes.

When drawing up a diagram of the rafters of a shed roof, it is worth considering the direction of the wind and positioning the slope so that the roof is not torn off by a strong gust.

Approximate parameters of shed roof elements

It is possible to make layered rafters from grade 2 lumber. Most often, these are round hewn logs, plates, which are a log hewn on both sides, timber or boards sewn in pairs.

The cross section of the rafters is determined by the load on the roof from wind, snow and roofing. To determine the parameters of the elements of a shed roof, you can use a computer program.

But in most cases these values are constant:

The truss frame, covering the span of more than 4.5 meters, should be erected from a log and plates with a diameter of 18-20 cm and a beam with a section of 10 * 15 cm or 15 * 15 cm.
For smaller spans, you can build a frame of logs and plates with a diameter of 12-18 cm and a bar with a section of 10 * 10 cm.

In both cases, it is allowed to replace the beam with double boards, the final size of which is similar to the required beam section.

It is very important to understand that building truss systems for shed roofs does not follow from smaller components. Even for minor buildings, the indicated parameters are the lowest limit.

For the manufacture of Mauerlat, it is recommended to use a bar with a section of 18-20 cm. For struts on roofs of great length, it is allowed to take a bar with a section of 8 * 8 cm, logs with a diameter of 10 cm or double boards, the total size of which is 2.5 * 15 cm.

Runs of large-span shed roofs are arranged parallel to the slopes. In this case, they are used as an additional support and increase the strength characteristics of the structure. For fastening the girders, the installation of supports and a bed is carried out, based on the construction technology of a gable roof. In this case, it is not the formation of the ridge, but the support of the plane of the long slope is provided. For the manufacture of purlins, a bar with a section of 18 * 18 cm or a log with a diameter of 20-26 cm is used. Racks for purlins can be made from a bar with a section of 12 cm or a log with a diameter of 13-20 cm.

The distance between the rafters of a pitched roof

The rafters are installed at a certain distance from each other, which depends on the size of the box over which the roof is being erected. The slope, which will serve as a support for the rafters, must be divided into segments so that the elements of the system are located at the same distance from each other. In this case, the dimensions of the materials used and their type should be taken into account:

If timber or plates were used for the manufacture of rafters, then the distance between them should be 1.5-2 meters.
When using double boards, the rafters are placed in increments of 1-1.75 meters.
If the rafters are made of a single board, then the distance is reduced to 0.6-1.2 meters.

If it is planned to build an insulated roof, then the size of the insulation can affect the distance between the rafter legs. The thermal insulation material must sit very tightly between the elements of the truss system. In this case, the formation of cold bridges is excluded, which leads to a reduction in heat loss. See also: "How to put the rafters of a shed roof - the rules for calculating, installing and fixing."

When determining the step between the rafters, you should pay attention to one more thing: an increase in the set step leads to additional costs for the crate. In this case, it is allowed to use a solid version or with a small step. Therefore, even at the design stage, it should be determined what is more profitable: frequent lathing or more rafter legs.

As with all pitched roofs, the rafters of a shed roof are fastened with anchor bolts embedded in the wall during their construction, or crutches that are driven into a wooden wall. In addition, every second rafter is fixed with a twist of annealed wire. The rafter is fastened to the wall at a point located 0.2-0.3 meters below the Mauerlat. The wire is fixed depending on the material used to build the walls. The twist is laid in the brick walls during the laying process, the wire is attached to the wooden walls with the help of staples.

To better understand the structure of the shed roof rafters, it is worth considering in more detail the installation options for such structures.

Fastening rafters for a pitched garage roof

Very often, garages are built from foam concrete blocks, so you should find out how the truss system works in this case. If a reinforced concrete belt is not poured in the upper part of the walls, then a Mauerlat must be laid without fail. Shed roofing system involves the use of timber laid on the front and rear walls of the garage, which have different heights.

When solving the problem of how to properly install the rafters on a shed roof, you must adhere to the following order:

A beam with a section of 10 * 15 cm is laid flush with the inner surface of the walls. As a result, a roof mauerlat with one slope is formed. To protect wooden elements from the effects of foam concrete, laying on a waterproofing material should be carried out. To fix the Mauerlat, it is recommended to use roofing corners measuring 9 * 9 cm, installing the mount at a distance of 0.8 meters. Additionally, they can be reinforced with a cast jumper. The corner is attached to the wall with dowels with a diameter of 14 mm.
A rafter leg template is made using a 5 * 20 cm board. The length of the shed roof rafters is determined as follows: the workpiece is installed on the Mauerlat, leaving a margin at the top and bottom up to half a meter. This margin should slightly exceed the standard width of the cornice overhang, 0.4-0.5 meters. After installing all the rafters, the excess sections are cut off.
Mark the tie-in points on the rafters, remembering that the tie-in should not be very deep. Most often, this parameter is a third of the width of the board.
Mark the walls, making sure that the distance between the rafters and the wall is at least 5 cm.
Using a template, they make rafters for the entire roof, install and secure them with brackets or corners.
Determine the width of the overhang and make a filly template. To do this, you can use cutting boards. The finished template is used for the manufacture of all cornice elements. When installing them, a waterproofing material is required to prevent contact between the wood and the concrete wall.
Align the size of the rafters for a shed roof and nail a windboard around the entire perimeter, using material 2.5 * 10 cm in size for this.
The truss system for a shed roof over a garage made of foam concrete blocks is considered ready. Next, a crate is stuffed onto the rafters, determining the step depending on the roofing material.

In the variant under consideration, the cornice overhangs were formed by means of fillies. You can use another option, which involves the removal of the Mauerlat beyond the perimeter of the building. Removal is determined by the width of the cornice overhang. The length of the rafters in this case also increases by the width of the overhang. Between the two extreme rafters, it is necessary to make a takeaway. All other actions are performed according to the standard plan.

Installation of a single-pitched truss system over an extension

Very often there is a need to make an extension to the main building. To match the additional structure with the general exterior, it is recommended to make a shed roof. In addition, this design will not retain precipitation.

The rafter system in this case should have a slope of about 20 degrees. The supporting wall of the house and the opposite wall of the extension will become the support for the rafter legs. If the extension has a length of more than 4.5 meters, then it is necessary to install struts that will ensure the rigidity of the truss system. Struts are recommended to be installed at an angle of no more than 45 degrees.

For the manufacture of rafter legs, boards of 5 * 20 cm are used, which are installed in increments of 0.7 meters. Struts can be made from boards 5 * 15 cm in size, and for crates it is better to choose boards 2.5 * 10 cm.

The construction of a truss system with one slope is as follows:

A waterproofing material is laid on the brick wall of the extension, and a beam with a section of 10 * 15 cm is installed on top of it flush with the inner plane of the wall. The beam is fixed with bolts installed at intervals of 8-10 cm.
In the bearing wall of the house, grooves are made 12 cm deep and slightly wider than the thickness of the rafter. The distance between the grooves should be about 0.7 meters. Another answer to the question of how to fix the rafters on a pitched roof can be the use of U-shaped metal brackets fixed on the wall.
A rafter template is made from a board measuring 5 * 20 cm.
According to the templates, all rafters are made and installed according to the grooves or brackets made. The upper part is fastened with metal corners, screwed on one side to the wall, and on the other to the rafters. At the bottom, fixation is performed with brackets or corners.
Using a piece of board, make a brace pattern. It should be remembered that the angle of inclination should not exceed 45 degrees, and the stop at the bottom should be placed 0.2-0.3 meters below the height of the opposite wall.
To determine the location of the grooves for the struts, you need to visually draw a vertical line from the top groove and step back 5 cm in any direction. The grooves should also be located at a distance of 0.7 meters from each other.
To install the brace in the groove, you need to make a saw cut of the lower corner of the brace. In this case, the saw cut should be 0.1 m.
To determine the line of the upper gash, the brace is installed in the groove, and the top is applied to the rafter. The place of their intersection determines the upper cut.
From this template, you need to make the rest of the struts and install them using metal gear plates.
Cornices are formed with the help of filly mounted on the inclined walls of the extension. Under the filly it is necessary to lay waterproofing.
Next, the truss system is sheathed with a wind board around the entire perimeter and the crate is hammered.

According to the above scheme, it is possible to install a single-pitched truss system over verandas and utility blocks.

How to fix a shed truss system over a barn

Minor outbuildings and summer kitchens do not need a strong roof, so it is better to use a shed roof for them. For example, consider the scheme of the truss system of a shed roof over a shed designed to store garden tools. This building is made according to the principle of erecting a frame for greenhouses, in which the vertical posts are connected by piping along the perimeter. The front wall has a slightly higher height than the rear wall, so the posts are connected by separate crossbars.

The algorithm for constructing a truss system for a shed roof over a barn involves the following steps:

Make a template for the rafter leg. To do this, apply the board to the end and mark the places of the cuts at the top and bottom.
According to the templates, the rest of the rafters are made. Make markings on the walls of the barn and fix the rafter legs. When building light buildings, it is enough to use nails or self-tapping screws.
The wind board is nailed after the installation of the sheathing around the perimeter of the building.

The examples given can be used as a basis for individual designs, so the design of a shed truss system must be known in detail.

Shed roof truss system: rafter attachment, diagram, how to fix, install correctly, device, system size, length, installation

Shed roof truss system

The shed roof truss system is a simple structure. It attracts with its reliability and economical consumption of material. The construction of a shed roof is permissible on its own and is carried out in a short time.

It is popular for garages, outbuildings and sheds. Residential buildings are rarely covered with a roof with one slope, but such options are found in the implementation of original architectural ideas for building a building. Despite the simplicity of the design, work on the creation of a roof is a very important stage and requires compliance with the technology.

Rafter frame single-pitched design: installation nuances and elements

The scheme of the rafter system for a small building is quite simple: inclined rafters laid on the mauerlat cover the distance between the end walls. The span of the building in this case is no more than 4.5 m. The angle of inclination of the slope forms the difference in height of the opposite walls. It can be provided in two ways:

install special supports on one of the walls under the upper edges of the rafters;

when laying load-bearing structures, perform one above the other.

When orienting the slope, the low part of the roof is directed towards constant winds, this will ensure the stability of the frame against high loads.

The function of the truss frame is to redistribute the constant and emerging loads on the roof between the load-bearing walls. Its constituent elements are:

mauerlat - a beam at the base of the structure, connecting it with the walls of the structure;

rafters - a board or timber that forms the basis of the frame;

struts, racks, beds - elements that reinforce the structure with a span of 6 to 9 m;
lathing - slats stuffed at a certain technology distance are the basis for roofing and reinforce the truss system.

A single-slope structure is characterized by less windage than systems with a large number of slopes, but when designing it, it is necessary to take into account the weight of the snow cover. This is especially true for a roof with a small slope angle of 8-10 degrees. When creating drawings, the location and size of all elements of the truss system, as well as the mounting schemes for the frame nodes, are noted.

The distance between the rafters of a shed roof is recommended within 60-80 cm, this allows you to provide sufficient strength for any coating used. The presence of overhangs 25-40 cm long on each side of the building guarantees the removal of rainwater from its walls, excluding their erosion.

Advantages of a pitched roof

Lumber consumption is significantly reduced compared to more complex structures.
The cost of construction is reduced.
Large selection of roofing materials as a finishing coating.
Installation of the truss system can be done independently, keeping within a short time.

How is the angle of inclination determined?

The slope of the slope is one of the main parameters of the roof. The intensity of the load on the rafters directly depends on this indicator. Main selection criteria:

The amount of precipitation in the region.
Type of roofing.

A large angle contributes to the unimpeded descent of snow, but leads to additional material consumption. A slight slope reduces the effect of wind, but requires frequent cleaning of the roof from snow cover. The optimal angle is also associated with the type of roofing, for each material there is a recommended parameter in degrees:

metal tile - 25;
slate, ondulin - 20;
roofing material and other rolled materials - from 5 to 10;
corrugated board - 20;
natural tiles - 35.

Preparation of lumber before installation

The operating time and reliability of the roof depends on the quality of the lumber used in the construction of the frame. The use of dry softwood timber is recommended. Wood should not have knots and damage. Before installation, it undergoes mandatory treatment with an antiseptic and flame retardant, these compounds protect against decay and fire. The size of the beam depends on several factors:

span length;
roof load (snow, wind, etc.);
slope angle.

The cross section of boards for rafters is 50 × 150 mm, 60 × 180 mm, timber for Mauerlat 150 × 150 mm, for lathing 50 × 50 mm.

Stages of installation of the truss system

The construction of the frame begins with the laying of the Mauerlat. Before mounting on the walls, the timber is wrapped with roofing material for waterproofing. The base is attached to the studs laid during laying or with the help of anchor bolts.

Installation of rafters is carried out on a fixed Mauerlat. For a strong fixation, it is necessary to make cuts on the boards. To ensure that all tie-ins have the same size, they are made according to a template. The upper part is sawn with a bevel, which provides the possibility of deflection of the rafters. The lower notch serves as a strong emphasis on the Mauerlat.

The roof rafters are fastened with nails and corners screwed with self-tapping screws. You can simplify the installation of the frame by installing the extreme rafters, and stretching a rope between them that defines the plane.

With a run length of more than 4.5 m, a brace is installed at an angle of 45 degrees, one of its edges rests on the rafter, and the other on the Mauerlat.

The end of the installation will be stuffing the crate. Its bars are located perpendicular to the frame, the fastening step depends on the finish coating. A continuous crate is made under the rolled material. Moisture resistant plywood or OSB boards are used for covering.

After installing the truss system, a waterproofing sheet is laid and the roof is insulated. The final stage of work is the installation of roofing.

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I consider the shed roof system to be the most acceptable option for arranging a garage or barn. A person with minimal knowledge in construction will be able to mount such a roof system. Just do not exaggerate your abilities and knowledge in construction.

Installation and schemes of the truss system of a shed roof

What parts does a shed roof consist of, preparation of materials and components. Installation procedure and important nuances that you need to know about.

However, even in the simplest carpentry, there are tricks that require thorough study. The future performer needs to know firmly how the shed roof stacks are fastened in order to exclude deformation and damage to the elements of the frame system.

The scheme of the truss frame of a pitched roof is extremely simple. It is a series of parallel-laid boards or beams, resting their edges on two walls of different heights. To install and fasten the rafter legs to the building structure, a transition element made of wood is used.

Depending on the type of box to be equipped and the material of the walls, the function of the transition element is performed by:

Mauerlat. In a shed roof scheme, these are two separately laid wooden beams that complete concrete or brick walls.
The upper strapping of the frame structure. Mounted on top of the racks of the frame is a belt made of double-stitched boards or timber.
The upper crown of the foot, made of timber or logs.

The rafter legs and the elements in contact with them are made of wood, which has the ability to change its own dimensions following fluctuations in the humidity background and temperature changes. In spring and autumn, especially during the rainy season, the length of the rafter legs will be somewhat longer than in dry summers and frosty winters.

Imagine what will happen if the rafter, rigidly fixed at the top and bottom, increases in size. Gaps will appear in the waterproofing, fasteners will loosen, slate sheets will move, move. In addition, the deflection and heaving of the roof frame will certainly affect its wear resistance.

However, changes in the linear dimensions of the rafters are not at all the main hitch of wooden truss systems. An unpleasant surprise, if not taken into account, will be the sediment of a newly built box.

It is most pronounced near wooden walls, but it is also very typical for structures made of concrete and brick. Recall that shed roofs rest on walls of different heights. Without calculations, you can understand that they will drop by different values. Those. there is a threat that, due to the difference in the subsidence of the walls, the new roof will not just change the angle of the slope. There will be a possibility of violation of nodes with extremely negative destructive consequences.

Despite the simplicity of shed roofs and the direction of laying rafters close to the horizontal, the listed risks must not be forgotten. The knots used in fastening the rafter legs of a shed roof must take into account the "whims" of the wood.

The work of the developer of his own shed roof project is to find the right solution for three important tasks, according to which:

It must be possible to move wooden parts relative to each other.
All possible causes of broken connections should be ruled out.
It is necessary to give the rafters the opportunity to adapt to the effects of wall subsidence so that they can take a stable position.

The rafter legs of shed roofs erected over walls of equal height are classified as layered. The hanging type is used if the equipped box has walls of equal height, and the slope is formed by rafter triangles.

With the fastening of triangles, everything is clear: with the horizontal side they are installed on the harness or Mauerlat, they have the maximum docking area with the supporting elements, and are fixed in the usual way.

With layered rafter legs, everything is much more complicated. They are installed at an angle to the supporting elements. Without processing and preparation for installation, the rafters have only two unreliable points of contact with the strapping or Mauerlat.

No matter how powerful the fastener is, two points are not enough for a solid fit of the part. Even with a slight impact, such a ramp will simply slide down along with a continuous crate and a multilayer one. However, there are methods invented by ancient builders to avoid such troubles.

In order to prevent unwanted movements, the contact area of \u200b\u200bthe rafter and the supporting element is increased, for this the following is done:

A selection of notches. These are cuts in the form of a triangle or a triangle with a tooth. They are cut out exclusively on the rafters, so as not to weaken the supporting Mauerlat.
Washed down the upper or lower edge of the rafter leg, which creates a support platform that increases stability. It is carried out strictly vertically or horizontally.

Depending on the type and place of sawing or trimming, cuts and cuts may or may not restrict the movement of a wooden part. Restrictions are considered relative, because there are no absolutely rigid fasteners in the construction of pitched roofs. Specialists classify the used nodes according to the degrees of freedom: from one to four.

In the construction of roofs with one slope most often appear:

Single degree of freedom tie-downs are virtually fixed joints that allow the rafter to rotate slightly around the tie-down point.
Two-DOF fasteners are joints that allow rotation around the fastener and slight horizontal movement.
Mounting points with three degrees of freedom - connections that allow rotation and displacement horizontally and vertically.

The presence of degrees of freedom does not mean at all that the rafter will be able to freely rotate and move around the node. They are fastened quite rigidly, because they have to hold the crate, or another type of coating, snow cover.

The connection will show its own capabilities only if the load is exceeded. Then the rafter legs will just move and take a new position, and the system will remain undamaged.

Any shed roof scheme clearly depicts the presence of at least two connecting nodes. We divide them conditionally into upper and lower. In the construction of roof trusses, the rule applies: if one of the nodes is fixed rigidly, then the second should have more opportunities for movement.

Projecting and simplifying the technological principle, we can say: if the fastenings in the upper nodes of a pitched roof are rigid, then the lower connections should be looser in order to allow displacement when the pressure is exceeded. And vice versa: if the lower mount is practically motionless, then at the top the rafter must be provided with some kind of reserve for movement and rotation.

After getting acquainted with the theoretical side of the issue of fastening the rafters of a shed roof, you can proceed to practical research on the demanded nodal schemes. Note that most projects of systems with a single slope are designed for the installation of rafters that form overhangs due to their own length. However, when covering large spans, it happens that there are not enough standard sizes of lumber. In these cases, fillies are sewn to the rafters, creating an overhang. They are installed on the side of the installed leg and do not affect the principle of knot formation at all.

The second reason for using fillies in the formation of overhangs is the too heavy rafter, which is very difficult to lift and install. The third prerequisite lies in the features of nodal fastenings: if the lower heel is installed on a slider with a trimmed edge.

No. 1: Support at the top and articulated bottom

A scheme with a rigidly fixed top and a relatively movable bottom is used in the construction of roofs over extensions, in the construction of objects with a steep roof and a significant difference between the height of the supporting walls.

Simply put, where the upper edge of the rafter rests against a wooden beam, a run or wall of the main building and no space is left for it to move. The lower node in such situations is calculated on the slider, which allows it to move slightly.

The algorithm of the classic version with the top resting on the run:

We install the supports of the running frame. On the strapping of the frame building on opposite sides, we install supports sewn from three pieces of board 25 × 100. The middle segment should be 75mm shorter than the extreme ones in order to form a kind of notch.
We build a running frame. We put a board 25 × 150 of the required length in the recess.
We apply a board 25 × 100 of arbitrary length to the end of the future roof, but more than the diagonal drawn from the top of the running frame to the strapping, by about 30 cm. We mark the vertical line of the upper gash, outlining the adjacent edge of the run. We mark the line of the lower gash and the vertical for trimming the edge of the rafter.
We cut out the rafter according to the marks, try it on in fact, if necessary, correct the cuts.
According to the made template, we cut out and mount the rafter legs.

We select the type of fastener based on the expected load. It is more convenient to fix the top with corners, the bottom with corners, by screwing no more than three self-tapping screws into them, or with sliding supports. If necessary, the lower knot can be stabilized - sew a support bar to the bottom of the rafter leg.

The connection node with the run can be designed a little differently: the rafter is laid on the beam using a notch. Here the groove is selected strictly according to the size of the material. But if it is necessary to increase the degree of freedom, the horizontal wall of the cut is beveled at a slight angle, and the lower unit is equipped with a sew-on bar.

No. 2: Top and bottom are hinged-fixed

The scheme is applicable when arranging boxes whose walls have already undergone intensive shrinkage. Suitable for isolated objects. The upper node is made in the form of a triangular cut, the lower one is in the form of a gash with a tooth resting on the Mauerlat.

The process of building a shed truss system:

We install the blank board with an edge on the Mauerlat bars anywhere on the roof.
Lay a well-trimmed piece of board flat on the lower Mauerlat. We put it so that the extreme edge coincides with the inner edge of the Mauerlat. Having outlined the cut, we obtain the outline of the lower attachment point.
We transfer the cut to the area of \u200b\u200bthe upper cut and outline it, because the lower heel of the rafter will drop by this amount.
The blank with the knots drawn and then sawn out will serve as a template. Using it, we make the number of legs specified by the project.
We install rafters. We fix at the bottom with staples or hairpins, at the top with corners.

If you need to increase the degree of freedom, by analogy with the previous method, the vertical edge of the upper notch will need to be slightly beveled. The cutting angle will then not be 90º, but 95 - 97º. Experienced carpenters make simple cuts directly on the object, turning the workpiece upside down. Novice performers should not imitate in the early stages.

The rafter template is used in roof construction only when there is no doubt about the geometric characteristics of the box. In reverse situations, the rafters are tried on and made individually. First, the extreme elements of the system are installed, then ordinary legs are stretched between them.

One of the variations on the theme of two hinged-fixed nodes involves the device of a vertical gash at the top and a cut with a tooth at the bottom. Work on their device is carried out as follows:

We install the blank board on the Mauerlat so that its lower corner is directly above the outer edge of the beam.
At the top, using a piece of board, mark the vertical line washed down (x) and measure its length.
We transfer the length of the upper gash to the region of the lower node. Set aside the length of the gash (x) up vertically from the inner upper edge of the Mauerlat.
From the resulting point, draw a horizontal line. The result is a cut with a tooth.
We cut out the nodes according to the marks, set them in place, fasten them with corners, duplicate the lower nodes with brackets.

With an increase in the size (x), the slope of the roof will increase, with a decrease it will decrease.

No. 3: Free top and hinged bottom

An ideal scheme for the construction of a shed roof with rafters, the edges of which are released beyond the walls. After some adjustment, it can be used in the arrangement of outbuildings.

We install the workpiece with an edge on the upper and lower Mauerlat beam with the removal of the edges beyond the walls. Here you need an assistant to hold the board to the canopy.
We apply a template - a trimmed board cut sequentially to the lower and upper Mauerlat so that the outer edge of the template coincides with the outer edge of the bars. We mark the lines of the upcoming cuts.
We select cuts according to the outlined lines. The vertical wall of the upper cut is slightly bevelled.
We install the rafter, fix it at the top with nails or corners, at the bottom with brackets.
We manufacture and install the remaining rafters in the same way.

It is clear that mobility with its antagonist is a relative concept. However, they should not be taken lightly. It is required to take into account the degree of freedom of the node both during the design period and when choosing fasteners. The lack of mobility of the structure will lead to deformation, the excess will contribute to instability.

No. 4: Mobility of both mounts

A scheme with two movable nodes can be used if both fasteners have no more than two degrees of freedom. Those. mixing horizontally exclude restrictive devices installed at the top and bottom.

Consider an example in which the rafters of the extension are laid at the top into niches cut in the wall. This means that horizontal displacement is excluded, rotation and some vertical movement are possible. The bottom is planted with the help of cuts, but in the horizontal direction it is limited by metal corners.

The actions of the builder of the "single-roll" step by step:

We prepare the object for work. We put a mauerlat made of 100 × 150 timber on the brick wall of the extension. We lay it on the wide side closer to the inner edge of the wall. We fasten with anchors after 80 cm. In the main wall of the building at the design height, we cut out the grooves for the upper heels of the rafters. The depth of the cuts is 12 cm, the step between them is 70 cm. If you do not want to mess with gouging, you can use metal brackets screwed to the wall.
We make a template for the rafter leg. We set the blank board with the upper edge in the groove, the lower on the Mauerlat. Departing from the lower corners of the workpiece 10 cm in the horizontal direction, we draw two triangular cuts.
According to the indications of the template, we make rafters. We install them, fix the position with metal corners.

The device method is valid for overlapping spans up to 4.5 m. If you need to cover a larger span, the rafters will need a support group as part of the struts.

No. 5: Rigid attachment to the sloped harness

The method is used in frame construction, because it is possible to lay the supporting element at an angle only on racks sawn at an angle. Either the racks of the frame itself, or the cantilever-running structure mounted on the box, are sawn obliquely. In principle, the latter option is quite suitable for the construction of a shed roof on concrete and brick walls.

Stages of the device of a shed roof along an inclined strapping:

We assemble the structure that creates the slope of the roof. On the gable side of the frame building, we mount short racks with an upper edge sawn at an angle.
On the sloping top of the racks, we lay the board in one row for small outbuildings, in two for more serious houses.
We equip the end sides of the roof with frames in the form of a right-angled triangle, the hypotenuse of which should repeat the slope line.
We apply the rafter to the end of the roof to mark the line of the lower gash.
According to the template, we make the required number of rafter legs. We install them on the harness, fix the position of the elements with metal corners.

Without a shadow of doubt, we will classify the latter method as the simplest one. Of all the ways of attaching rafters to the strapping and Mauerlat beams of a pitched roof, this one is the most conducive to attempts at self-implementation.

Final fixing work

After installing the entire row of rafter legs, we check the design position of the elements, the distances between them. We apply an arbitrary board flat to the ramp frame, identify flaws and correct flaws. Then we fasten the rafters with brackets or bundles to the walls through one in regions with medium and low wind activity. We fix each leg in areas with high wind load.

Filly, if they are planned for installation, are made of material with dimensions half as large as the dimensions of the rafter legs. Sew them on the side to the rafter. The length of the sewn section is on average 60-80cm.

Video for a visual study of the process

The presented methods and schemes for fastening the rafters of a pitched roof have been tested by practice. They are used most often in a "pure form". However, some adjustments according to specific specifications are not excluded.

The construction of a roof is planned, do you need a simple structure with good strength and reliability characteristics? In this case, a shed roof would be an excellent option. It will make your house, garage, outbuilding or other structure original in its own way. In addition, the shed roof truss system is easy to install. It can be done without building experience.

In this article

Why single-sided

The construction of a roof from 1 slope has the following advantages:

When building on a shed roof, you can use any type of roofing material. Because the angle of inclination can be as small as possible, an almost flat roof can be built.
The sail of this design is much less than that of a gable. This option can be used in areas with strong winds.
Ease of installation and operation. You can build it with your own hands.
Light weight compared to other types of roofing.
For a shed roof, slopes of several floors can be built. This solution will give design to your home.
The construction of a shed roof is the most economical and does not require much time.
In this design, water rolls only on 1 side.
The roof is suitable for construction of any type.

Like any other design, a shed roof has several disadvantages:

With a small angle of inclination, the area of \u200b\u200bthe attic space is minimal.
Has a less attractive appearance. What can be corrected with the imagination of the designer.

Design calculation

The rafter system of a shed roof, in fact, consists of rafter legs of a layered type. The rafters must be fixed parallel to each other. The rafters, in turn, are supported by two points. Basically, they are the load-bearing walls of the building.

Create a ramp angle

The required slope angle of the ramp is achieved in several ways:

When developing a building project, one of the walls on which the rafter legs will lie is made a little higher. This method is common, as it greatly simplifies the design of rafters. But in this case, more material will be used to build walls. The side walls, running parallel to the rafters, are shaped like a trapezoid.
This method is a variation of 1. Also, when planning, frame racks are taken into account. In this embodiment, the extreme racks on one side are higher, and on the other they are lower by a certain height.
With the same height of the walls, vertical racks of the required height are installed on one of the walls. At first glance, this design is unstable, since the rafter triangles have free movement to the right and left. But this fragility of the structure is eliminated by installing the frame lathing and sheathing the frontal part of the roof with wood.
One-slope trusses can be used. This method is good enough that you can build one truss, fit it to the desired dimensions and use it as a template. And with the help of a template, you can build the rest of the farms on the ground. There are ready-made roof trusses. They are ideal for any type of roof. For them, it is enough just to install and fasten to the Mauerlat. Further, you can freely sheathe a shed roof with a crate.
When building an extension near the house, this method is used. In this case, racks or a wall can be planned on one side of the extension, and on the other, we already have the main wall of the finished building. Fastening to it can be done using a well-fixed horizontal run or separate fasteners, also aligned horizontally. All fastenings on the wall of the building are made higher than the racks or the wall of the opposite side.

Determine the side of the roof slope

Often the question arises, in which direction to determine the slope of the roof? In the case of an extension to the house, there are no special options. The slope is made in the direction from the building to ensure free flow of water during heavy rains.

If a separate building is planned, then here you can choose a side. Basically, the location of the ramp is done on the back of the building. Although there are cases when the ramp is produced on the front side. In such a situation, the choice is based on the design style of the building, the territorial features of the site, from which side it is more convenient to lay the communications system, and the like.

But in this case, you should also not miss some nuances:

It would be more correct to place a shed roof in the windy direction. Thus, the impact of wind is minimized. After all, the wind directed into the roof with a small angle has practically no effect on it.
For a rectangular building, you can choose the location of the slope along or across. But here it must be remembered that the rafters of a pitched roof cannot have an infinite length. For a certain distance, they need to be strengthened. According to the rules, the free size of the rafters is 4.5 meters. When installing a rafter system up to 6 meters, a rafter leg is required. It is placed at an angle of 45 degrees to the support beam.

The steepness of the slopes

If we are talking about a shed roof, then in most cases they choose an angle not up to 30 degrees. This choice is explained by the fact that the roof is highly vulnerable to wind load from the front side of the building. Although they try to build the slope of the slope from the windy side, this does not exclude the presence of wind from the side of the facade. Therefore, a steep angle of inclination creates a high lifting force. In strong winds, a high load is placed on the roof structure.

A slope below 10 degrees is also unacceptable, since the load on the rafter system immediately increases during a snowfall. With the onset of a thaw, an ice crust appears on the edge of the roof, preventing the free flow of melt water.

It is important to determine the angle of the slope of the roofing material. Indeed, for different materials, the manufacturer also indicates its slope angle.

Depending on the material, some standard values \u200b\u200bof the slope angle can be distinguished:

Up to 2 degrees - almost a flat roof. It requires at least 4 layers of rolled bitumen coating. It must be applied using hot technology. It also requires gravel dressing, recessed into the mastic.
3-5 degrees - involves three layers of roll coating. Gravel powder can be omitted.
9-15 degrees - with rolled material, 2 layers are enough. You can also use some types of corrugated board or metal tiles.
10-17 degrees - you can lay a wavy slate reinforced profile.
11-20 degrees - soft shingles.
14-25 degrees - asbestos-cement slate, at 25 degrees corrugated board and metal tiles lay down almost without restrictions.
27-50 degrees - ceramic, cement tiles.

Mounting

When building a shed roof with your own hands, for a correct and reliable installation, you need to use the drawings and detailed instructions, which will indicate all the dimensions and the amount of the required material. You can create a drawing diagram yourself or find a ready-made sample on the Internet. You can also order it from construction professionals.

Before starting construction, you need to choose a ventilated or non-ventilated type of roof. The first is great for living quarters, as ventilation provides a comfortable microclimate inside the building. All this is achieved with the help of gaps between waterproofing materials. The second type is suitable for the construction of a terrace or a warehouse.

The construction of rafters with a pitched roof

The truss system of a shed roof involves a couple of popular ways to mount it:

Fastening the rafters of a shed roof to load-bearing walls. In this case, the roof will turn out to be more economical and less lumber will be used for it. The load-bearing wall must be at the height of the roof. Since the upper part of the rafter rests on it.
A triangular truss is being constructed, which includes beams and posts. It will unite the construction of the rafters. With this method, you do not have to build a load-bearing wall to the height of the roof, but more wood will go. This method is convenient, since you can mount all the trusses below using a template.

When erecting rafters, additional supports and struts will be needed. The number of such complementary elements depends on:

The slope of the slope.
Rafter weights.
The length of the junctions of the roof with the wall.
roof material.
Materials of the heat-insulating layer.

Rafter pitch

The distance between the rafters can be determined by the box on which the roof is being erected. To ensure that the distance between the rafters is the same, the slopes on which the rafter legs rest are divided into equal sections. Depending on the installed materials, some values \u200b\u200bcan be distinguished:

For rafters from a bar, the step is from 1.5-2 meters.
When using paired boards, the distance between the rafters is 1-1.75 meters.
The use of single boards relies on a step of 0.6-1.2 meters.

Also, the type of insulation affects the distance between the rafters. It is recommended that the thermal insulation layer be rigidly installed between the rafters. After installing the truss system, you can go to the Mauerlat. It will help distribute the load on the walls.

The nuances of mounting the Mauerlat

Mauerlat is a complementary element of any roof. The lower edge of the rafter is installed on it. Its fastening is carried out to the bearing wall or between the beams of the rafter system. To fix the Mauerlat, it is necessary to use reinforcement, if the walls of the house are made of porous material, burnt wire, if the walls are brick, anchor bolts for a wooden house.

To extend the life of the Mauerlat, it is necessary to install it on a waterproofing layer.

Floor beams, their installation

In addition to the Mauerlat, for some shed roof structures, the installation of floor beams is implied. Rafter legs rest on them. Such beams are mounted with a step similar to the truss system. The fastening of the rafters to the Mauerlat is always done with the help of a gash. The gap between the rafters and the Mauerlat is minimized.

With a rafter system of more than 4.5 meters, rafter legs are installed. They give strength and eliminate the deflection of the rafter beam. The installation location depends on the width of the spans. A shed roof of a huge area, without exception, should include rafter legs. Otherwise, it threatens to break or collapse.

It must be remembered that with an increase in the step between the rafters, it will be necessary to reduce the step of the crate or make it solid.

When installing a shed roof, do not forget about some of the nuances:

You need to place the ramp on the windy side. To keep the roof from blowing off in the wind.
When calculating the truss system, you need to take into account climatic conditions. This is the amount of snowfall, heavy rains, wind strength. Even distribution of the load on the rafters will increase the service life.
Consider overlap when calculating materials.
The smaller pitch of the rafters of a shed roof allows you to withstand a higher load.

An example of a shed garage design

The walls are built from foam blocks. The first step is to install the Mauerlat. With a shed roof, these are 2 beams laid on walls of different heights.

The phased scheme for the construction of the rafter system consists of:

On the inner sides of both walls, we install a beam of 100x150 mm. We make its installation on roofing material waterproofing material. This will be our Mauerlat. We make Mauerlat fasteners using reinforced corners 90x90. For this we use dowels with a diameter of 14 mm.
We take a board 50x200 mm and install it on the Mauerlat with a margin of 50-60 cm. The margin should exceed the planned dimensions of the cornice. After that, everything unnecessary is cut off.
We mark further cuts on the board, the depth of which should not be more than 1/3 of the width of the board.
We mark the walls so that the last rafters do not touch them. The recommended distance is 4-5 cm.
Using the template, we make the rest of the rafters. Fastening is done with brackets or corners.
Given the width of the overhang, we produce fillies. We mount all the elements of the cornice so that there is a layer of waterproofing between the tree and the wall.
We cut off all the excess and fasten the wind board 25x100 mm.

The simplest garage design scheme is completed. The next steps will be the installation of the battens and the flooring of the roofing material.

The simplest covering used in the construction of new buildings is a shed roof, which every masterful owner can build with his own hands. If you are one of these homeowners and decide to make a roof with one slope on your own, then first go through 3 preparatory stages:

Make sure that this technical solution is suitable for your home.
Consider the design of the truss system and complete its drawing.
Familiarize yourself with the nuances of the selection of materials and the construction itself.

You will find all the above information in our article.

Scope of application and design flaws

The undoubted advantages of the shed roof shown in the photo are the simplicity and low cost of construction. Indeed, in comparison with a broken attic, and even an ordinary gable roof, a significantly smaller amount of building materials is spent on it. This is one of the reasons why this design is used in most budget buildings.

It is customary to make a roof with one inclined slope in the following types of buildings:

in separate baths, garages and sheds;
in gazebos and verandas attached to residential buildings;
on commercial real estate objects - pavilions, small shops and warehouses.

The picture clearly shows how much one facade is higher than the other.

But in private houses and large country cottages, a shed roof is quite rare, despite the cheapness. The reason for this is several significant disadvantages of the design:

Appearance. To ensure the slope of a single slope, it is necessary to withstand the height difference between the front and rear facades from 0.4 to 2 m. Not everyone likes this design.
The device of a residential attic space is practically excluded due to the peculiarities of the truss system.
Slightly pitched roofs have no usable attic space.

If you know about the listed shortcomings in advance, then it is quite possible to put up with them, since they do not play a big role for budget and outbuildings. But there is a nuance that, under certain conditions, eliminates the main advantage of shed roofs - low cost.

One slope looks very harmonious on the attached veranda

With a width of the overlapped span from 4.5 to 6 m, it is enough to strengthen the rafters with struts. If the distance between the supports exceeds 6 m, you will have to assemble a rigid roof structure - a farm, which will increase the consumption of timber. If we add here the costs of building up the front facade, then the financial picture will not be too rosy.

Advice. When deciding to build a shed roof with your own hands, weigh the pros and cons, compare with the costs of a gable roof of a residential building. If the width of the span does not exceed 6 m, or if there is a load-bearing wall in the center of the building, then there is no need to make a rigid frame.

The choice of truss system

In the construction of any roofs, 2 types of systems are used - hanging and layered. The former have only 2 points of support in the form of external walls, while the latter are placed on 3 walls (sometimes more), one of which is an internal partition.

If the width of your house or veranda does not exceed 6 m, then feel free to accept the hanging truss system shown in the diagram for execution. With a length of up to 4.5 m, the rafters do not need additional supports, and with a span width of 4.5 to 6 m, the installation of struts is required. This is the cheapest roof option, suitable for all kinds of outbuildings, sheds and small baths.

Note. A span of up to 7.5 m can still be covered with a hanging system if a frame ceiling is made of beams and a so-called truss truss is built. The bottom line is to support the middle of the rafters with a headstock - a rack with struts fixed on the ceiling beam.

Spans up to 18 m are divided into sections no more than 6 m long and are covered by a layered structure, whose device is shown in the picture. Under a long rafter made of two or three boards, additional supports are placed, fixed on the internal wall partitions. For rigidity, the trusses are interconnected by runs, as shown in the drawing.

As for the installation step of the rafters, for shed roofs erected in temperate and northern latitudes, it is better to take an interval of 600 mm. In the southern regions, where the snow load on the coating is small, this distance can be increased to 1-1.2 m. Take the roof slope angle in the range of 8-45 °, depending on the purpose of the building and other conditions. Step-by-step calculation of the angle is described.

From the graph, you can determine the minimum slope angle for various coatings

Work instructions

Before you make a shed roof, you need to choose the right lumber for the rafter system and the batten. We will make the following recommendations in this regard:

for a span up to 4.5 m wide, rafters from a bar 15 x 5 cm are suitable, up to 6 m - from boards 200 x 50 mm, spliced in pairs or in length;
a beam of 150 x 50 mm will go to the wall piping (Mauerlat) and beds;
section of racks, struts and runs - 10 x 5 cm;
the crate is made of boards 20-25 mm thick and 10-15 cm wide.

Advice. Fasten the frame elements to each other using nails or using galvanized self-tapping screws and bolts through metal plates and corners.

For waterproofing, you will need a roofing material and a superdiffusion membrane, and for laying the finish coating, you will need metal tiles, corrugated board or other roofing material. If we are talking about a residential building, do not forget about insulation: prepare mineral wool of the required thickness (or other insulation) and a vapor barrier film.

Mauerlat laying

The strapping beam should be placed on 2 opposite walls, where the rafter legs rest. If it is planned to support the layered system on internal partitions, then a board called a bed is also laid on them. The exception is log and frame houses, whose walls are ready for the installation of rafters.

The technology for laying Mauerlat on walls made of different materials looks like this:

Studs are embedded in the brickwork in advance, on which the strapping beam is attached. Before installation, the stone wall is covered with 2 layers of roofing material. If the studs were not installed, then the Mauerlat is fixed with anchor bolts or attracted with steel strips.
Porous walls built of aerated concrete, before installing the Mauerlat, are supposed to be connected with a reinforced concrete belt, as done in the diagram. Studs for fastening are laid in the monolith during pouring.
In wooden outbuildings (verandas, terraces) built by oneself, to support the rafters, a second board of the same width must be attached to the upper tie beam of the wall. To install the upper end of the rafter leg, it is necessary to screw a horizontal bar 15 x 5 cm to the wall of the existing building. This operation is demonstrated in more detail in the video below.

Note. When laying additional boards on the upper part of a wooden wall made of beams or logs, it is not necessary to lay roofing felt waterproofing.

Installation of rafters step by step

Before you build a frame, you need to determine the actual length of the rafters, taking into account the outlets for the walls that form the cornice overhangs. However, the visors can also be built up after installation, by nailing cut-to-size boards to the rafter legs - the so-called fillies. The minimum length of the roof overhang is 300 mm.

Advice. When it is required to join the boards along the length, lay them on top of each other so that the length of the common contact plane is at least 50 cm.

To build up the internal partition to the height of the inclined plane of the roof, assemble the frame from vertical supports connected from below by a bed, and from above by a run. The location of each rack should match the pitch of the rafters that will rest on them. For stability, secure the frame with struts.
Try on the rafter in place and cut it from below at three reference points in order to increase the area of \u200b\u200bfit to the Mauerlat and beds, as shown in the photo.
Install the rafter leg and attach it with self-tapping screws on the steel corners. Repeat the operation at 3 points, then move on to the next beam.
Trim the legs of the cornice overhangs, and then sew them on the bottom and sides with clapboard. It is more convenient to do this until the roofing is laid.

Note. If it is planned to make a flat ceiling in the room, then you must first install the floor beams, and then build the frame.

If the side gables are not laid out under the slope of the future roof, then they should be lined immediately after assembling the truss system. Otherwise, then you will have to do this work from the stairs or build scaffolding. Installation of the truss system of a shed roof of a large building, see the next video:

Lathing and finish

Before laying the boards on the roof slope, the truss system is covered with sheets of a superdiffusion membrane, which provides protection from wind and moisture ingress into the attic space. The canvases must be laid horizontally, starting from the bottom, and fastened to the upper plane of the rafters with bars of a counter-lattice with a section of 5 x 5 cm. The membrane should sag slightly between the rafter legs to drain water, and adjacent canvases should be glued together (overlap size - 15 cm).

Note. It is not necessary to lay a waterproofing membrane on shed roofs of sheds, garages and other non-residential and unheated structures.

Sheathing boards are nailed to the rafters with a step depending on the type of roofing:

under the metal tile - 35 cm;
for corrugated board and slate - 50-60 cm;
under shingles, bituminous and ceramic tiles, the crate is continuous.

The last step is the coating and insulation (if necessary). The thermal insulation of a shed roof is best done along the ceiling, leaving the unused attic cold. How to properly insulate ceilings is described.

Conclusion

Installation of a shed roof of an outbuilding or an open terrace will not be a big problem. Even if you have just started carpentry, you can build such a roof on your own or together with an assistant. Another thing is a residential building or a bathhouse, here you will have to work hard with fitting the frame and warming. For very detailed information about the assembly of frame roofs, see the training video:

Structural engineer with over 8 years experience in construction.
Graduated from East Ukrainian National University. Vladimir Dal with a degree in Electronic Industry Equipment in 2011.

The shed roof truss system has a number of advantages that make it a good choice for installation on auxiliary buildings, garages, extensions to the main building.

Benefits of a pitched roof

The device of a shed roof on buildings of various types is beneficial due to a number of factors:

low weight of the structure;
low cost of construction;
simple installation technology;
the possibility of using a wide range of structural and roofing materials;
ease of installation of the drainage system, chimney.

Rafters: design calculation and material preparation

the laying of one of the opposite load-bearing walls is carried out to a great height;
special supports are mounted on one of the walls, on which a run is laid to support the upper ends of the rafters.

The first option is most suitable for the construction of a structure from piece materials. The second method allows you to save building materials from which the walls are built.

Shed roof rafters for small spans are made of boards or beams. If the span exceeds 4.5 meters, you may need to install elongated rafter legs.

Garage roof rafter installation scheme

Installation of the extension roof

When choosing the angle of inclination of the roof of the extension, you should pay attention to the following points:

the greater the angle of inclination of the rafters, the less the danger of accumulation of rainwater or snow mass that has “moved out” from the main roof;
the rafters of an extension located on the south side may have a smaller slope than that of a similar structure on the north side, because. the sun promotes intensive evaporation of moisture.

Wooden rafters for a shed roof are sensitive to moisture. The places where the rafter legs adjoin the wall or main roof should be carefully sealed - for this purpose, a roof apron is installed.

Shed roof truss system: how to install, fastening, device

The device and fastening of the truss system for a shed roof. Design, installation and selection of rafter pitch for a shed roof of a house, garage or extension.

Fastening the rafters of a shed roof: a thorough analysis of the units used

The tempting simplicity of the roof with a single slope inspires thoughts about the opportunity to prove oneself in the field of a successful builder. The construction of an unpretentious design consists in the banal laying of rafter legs on the supporting walls. No complicated knots, intricate and numerous joints. However, even in the simplest carpentry, there are tricks that require thorough study. The future performer needs to know firmly how the shed roof stacks are fastened in order to exclude deformation and damage to the elements of the frame system.

Traditional "wooden" troubles

Depending on the type of box to be equipped and the material of the walls, the function of the transition element is performed by:

Mauerlat. In a shed roof scheme, these are two separately laid wooden beams that complete concrete or brick walls.
The upper strapping of the frame structure. Mounted on top of the racks of the frame is a belt made of double-stitched boards or timber.
The upper crown of the foot, made of timber or logs.

Imagine what will happen if the rafter, rigidly fixed at the top and bottom, increases in size. Gaps will appear in the waterproofing, fasteners will loosen, slate sheets will move, metal tiles will move. In addition, the deflection and heaving of the roof frame will certainly affect its wear resistance.

The work of the developer of his own shed roof project is to find the right solution for three important tasks, according to which:

It must be possible to move wooden parts relative to each other.
All possible causes of broken connections should be ruled out.
It is necessary to give the rafters the opportunity to adapt to the effects of wall subsidence so that they can take a stable position.

No matter how powerful the fastener is, two points are not enough for a solid fit of the part. Even with a slight impact, such a ramp will simply slide down along with a continuous crate and a multi-layer roofing cake. However, there are methods invented by ancient builders to avoid such troubles.

In order to prevent unwanted movements, the contact area of \u200b\u200bthe rafter and the supporting element is increased, for this the following is done:

A selection of notches. These are cuts in the form of a triangle or a triangle with a tooth. They are cut out exclusively on the rafters, so as not to weaken the supporting Mauerlat.
Washed down the upper or lower edge of the rafter leg, which creates a support platform that increases stability. It is carried out strictly vertically or horizontally.

In the construction of roofs with one slope most often appear:

Single degree of freedom tie-downs are virtually fixed joints that allow the rafter to rotate slightly around the tie-down point.
Two-DOF fasteners are joints that allow rotation around the fastener and slight horizontal movement.
Mounting points with three degrees of freedom - connections that allow rotation and displacement horizontally and vertically.

The connection will show its own capabilities only if the load is exceeded. Then the rafter legs will just move and take a new position, and the system will remain undamaged.

Details about the knots of a pitched roof

No. 1: Support at the top and articulated bottom

The algorithm of the classic version with the top resting on the run:

We install the supports of the running frame. On the strapping of the frame building on opposite sides, we install supports sewn from three pieces of board 25 × 100. The middle segment should be 75mm shorter than the extreme ones in order to form a kind of notch.
We build a running frame. We put a board 25 × 150 of the required length in the recess.
We apply a board 25 × 100 of arbitrary length to the end of the future roof, but more than the diagonal drawn from the top of the running frame to the strapping, by about 30 cm. We mark the vertical line of the upper gash, outlining the adjacent edge of the run. We mark the line of the lower gash and the vertical for trimming the edge of the rafter.
We cut out the rafter according to the marks, try it on in fact, if necessary, correct the cuts.
According to the made template, we cut out and mount the rafter legs.

We select the type of fastener based on the expected load. It is more convenient to fix the top with corners, the bottom - with corners, by screwing no more than three self-tapping screws into them, or with sliding supports. If necessary, the lower knot can be stabilized - sew a support bar to the bottom of the rafter leg.

No. 2: Top and bottom are hinged-fixed

The process of building a shed truss system:

We install the blank board with an edge on the Mauerlat bars anywhere on the roof.
Lay a well-trimmed piece of board flat on the lower Mauerlat. We put it so that the extreme edge coincides with the inner edge of the Mauerlat. Having outlined the cut, we obtain the outline of the lower attachment point.
We transfer the cut to the area of \u200b\u200bthe upper cut and outline it, because the lower heel of the rafter will drop by this amount.
The blank with the knots drawn and then sawn out will serve as a template. Using it, we make the number of legs specified by the project.
We install rafters. We fix at the bottom with staples or hairpins, at the top with corners.

One of the variations on the theme of two hinged-fixed nodes involves the device of a vertical gash at the top and a cut with a tooth at the bottom. Work on their device is carried out as follows:

We install the blank board on the Mauerlat so that its lower corner is directly above the outer edge of the beam.
At the top, using a piece of board, mark the vertical line washed down (x) and measure its length.
We transfer the length of the upper gash to the region of the lower node. Set aside the length of the gash (x) up vertically from the inner upper edge of the Mauerlat.
From the resulting point, draw a horizontal line. The result is a cut with a tooth.
We cut out the nodes according to the marks, set them in place, fasten them with corners, duplicate the lower nodes with brackets.

With an increase in the size (x), the slope of the roof will increase, with a decrease it will decrease.

No. 3: Free top and hinged bottom

An ideal scheme for the construction of a shed roof with rafters, the edges of which are released beyond the walls. After some adjustment, it can be used in the arrangement of outbuildings.

We install the workpiece with an edge on the upper and lower Mauerlat beam with the removal of the edges beyond the walls. Here you need an assistant to hold the board to the canopy.
We apply a template - a trimmed board cut sequentially to the lower and upper Mauerlat so that the outer edge of the template coincides with the outer edge of the bars. We mark the lines of the upcoming cuts.
We select cuts according to the outlined lines. The vertical wall of the upper cut is slightly bevelled.
We install the rafter, fix it at the top with nails or corners, at the bottom with brackets.
We manufacture and install the remaining rafters in the same way.

No. 4: Mobility of both mounts

A scheme with two movable nodes can be used if both fasteners have no more than two degrees of freedom. Those. mixing horizontally exclude restrictive devices installed at the top and bottom.

The actions of the builder of the "single-roll" step by step:

We prepare the object for work. We put a mauerlat made of 100 × 150 timber on the brick wall of the extension. We lay it on the wide side closer to the inner edge of the wall. We fasten with anchors after 80 cm. In the main wall of the building at the design height, we cut out the grooves for the upper heels of the rafters. The depth of the cuts is 12 cm, the step between them is 70 cm. If you do not want to mess with gouging, you can use metal brackets screwed to the wall.
We make a template for the rafter leg. We set the blank board with the upper edge in the groove, the lower on the Mauerlat. Departing from the lower corners of the workpiece 10 cm in the horizontal direction, we draw two triangular cuts.
According to the indications of the template, we make rafters. We install them, fix the position with metal corners.

The device method is valid for overlapping spans up to 4.5 m. If you need to cover a larger span, the rafters will need a support group as part of the struts.

No. 5: Rigid attachment to the sloped harness

Stages of the device of a shed roof along an inclined strapping:

We assemble the structure that creates the slope of the roof. On the gable side of the frame building, we mount short racks with an upper edge sawn at an angle.
On the sloping top of the racks, we lay the board in one row for small outbuildings, in two for more serious houses.
We equip the end sides of the roof with frames in the form of a right-angled triangle, the hypotenuse of which should repeat the slope line.
We apply the rafter to the end of the roof to mark the line of the lower gash.
According to the template, we make the required number of rafter legs. We install them on the harness, fix the position of the elements with metal corners.

Final fixing work

A shed roof is simple, economical in terms of material costs, and the minimum number of nodes is used during installation. We have a shed roof at the garage and gazebos on the site. Such a roof weighs little, the choice of material for the coating device is practically inexhaustible, it tolerates wind and precipitation well, does not flood neighbors nearby (but a good drainage system is needed).

Yes, in terms of material, a single-sided design is more economical, and also less labor-intensive. I would also like to add that the dismantling of such a roof is also simple, in comparison, for example, with a gable roof. Of the minuses, I can only name that if the roof is used on a garage or a bathhouse, a shed, then with the raised side it should look towards a higher building, for example, a house. And the building will be less exposed to winds, and even after rain, if a drainage system is not provided, water will not be poured into the house.

Attaching the rafters of a shed roof: step by step instructions from the masters

Properly executed fastening of the rafters of a shed roof will ensure the stability of the structure, the reliability of the nodes guarantees a long service life without problems.

Shed roof rafters: details and installation details

The pitched roof has always been popular due to its obvious simplicity and minimal cost. The sloping rafters of a shed roof, with both ends resting on load-bearing walls of different heights, inspire much less concern in terms of strength and stability than the complex system of gable roof rafters.

The correct choice of the location of the roof relative to the prevailing wind direction will help to ensure its maximum service life. It is equally important to choose the right slope.

A roof structure with one slope is most readily used for:

At the same time, they always strive to orient the slope of a shed roof in such a way that its low part is located towards the prevailing winds. This significantly reduces the impact of wind and other atmospheric phenomena on the entire structure. When installing a shed roof with your own hands, never forget about it.

Many are sure that the installation of a shed roof truss system is not at all difficult, and untrained people can assemble it.

It is quite possible, but when performing work on the roof, everyone needs to follow the safety rules - both professionals and amateur enthusiasts. This requires, at a minimum, strong ladders, mounting belts and strong ropes.

The shed roof scheme is really not very difficult for a person with a minimum set of technical knowledge, but “hatting” is absolutely inappropriate here. Thoughtlessly executed shed roofs of a garage, a utility block, and especially a residential building, can bring a lot of trouble and disappointment to the owner.

Wooden trailer with pitched roof

Roofing failure by a gust of wind, massive leaks or roof deflections from accumulated snow can spoil the mood of any person for a long time.

We hope everyone has already understood how serious it is - the installation of a pitched roof. However, subject to a few rules and the manifestation of creative thought, it is quite possible as a result of your efforts to get something quite acceptable in terms of design and functionality.

The design of single-pitched roofs is divided into two types:

A do-it-yourself non-ventilated version of a shed roof is mainly used in outbuildings-terraces. For the practical use of the roof area (arranging flower beds, fountains, small pools), the slope is chosen to be small - from 3 to 6%. However, such a farm requires special care in anticipation of the winter season.

Ventilated shed roofs are usually arranged with slopes ranging from 5 to 20%. Under the cornices on both sides of the roof, special holes are made for ventilation. The presence of a ventilated space between the waterproofing and the insulation prolongs the life of the building. In some cases, a combined roof option is chosen, where the slope is set by a variable thickness of the heat-insulating layer.

The low pitch angle of a pitched roof is beneficial in terms of material costs and the practical use of its area, however, there is a high risk of accumulation of large masses of snow in winter. This means regular cleaning of the roof, its damage, subsequent leaks and the constant risk of falling from a height.

When building a country house, installing a shed roof will significantly save money when buying building materials and paying for installation.

Shed roof rafters

Shed roof truss system

The purpose of the truss system is to redistribute the weight of the roof to the main walls with all the loads acting on it, permanent and temporary (from snow, wind, precipitation).

The truss system of a shed roof is its original skeleton, its supporting frame.

The calculation of a shed roof during design should take into account all loads with a multiplying factor. If in recent years there has been a tendency towards an increase in the peak values of one-time precipitation or storm winds, then it would be useful to take this into account in the calculation.

At the same time, it will be fair to note that, due to their low windage, single-pitched roofs experience less wind load than their multi-pitched modifications.

If you are interested in a sloping shed roof, then you need to know that its constructive solution will consist of:

the location of the supporting walls;
type of attic floor;
the presence of internal walls;
the size and configuration of the building;
span span.

According to the method of support and the method of fastening, the rafters are divided into:

Sliding rafters with their top rest on a ridge log, and are attached to the walls with special metal corners with a movable “sliding” plate. Sliding types of rafters are usually used in log houses, where the shrinkage of wood during the drying of the log house is very significant (up to 5% of the volume of wood).

The shrinkage stresses are so great that they would easily break the rigid fastening of the elements. The danger is not so much the shrinkage itself, but its unevenness. Therefore, the "sliding" plates fixed to the rafters have a power reserve in the lugs of the corners attached to the wall.

The external walls of the building serve as a support for inclined rafters (rafter legs). With their connected upper part, they rest on a ridge beam supported by uprights and struts. The inner walls serve as the base for the struts and struts.

The step between the truss systems is assigned in the range from 0.6 to 1.4 m.

The larger the size of the roof and its mass, the smaller the pitch of the rafters. The cross section of the rafters is selected taking into account the weight of the roofing and snow load. Each drawing of a shed roof must contain indications of the size of the sections of all elements of the truss system. After the installation of the inclined rafters is completed, a crate is attached to them ( see video below), which is the basis for roofing.

If you carefully study the drawing of a shed roof with inclined rafters, then it becomes obvious that there is additional support for struts and racks on the inner wall. When the span is large enough, and there are no intermediate supports for the rafters, then hanging rafters are used - the most difficult type of rafters to perform.

They are a triangular structure assembled in one plane, including two rafter legs connected at the top point and a horizontal lower puff. She ties the lower ends of the rafter legs. It is thanks to the tightening that the rafters do not create spacer loads on the walls, transferring only vertically directed pressure from the weight of the roof to them.

Therefore, for a hanging rafter system, a Mauerlat device is not necessary, which simplifies and reduces the cost of installation.

Even on the ground, the “triangles” of the hanging rafters are connected in pairs, fastening the legs with sheathing bars, and the screeds with attic floor boards. Then each volumetric truss assembled in this way is lifted up and placed in the design position on the load-bearing walls.

Details of roof structures are made, as a rule, from coniferous wood (pine, larch). For rafters, an edged board of 200x50 or 150x50 mm is usually used, and for lathing - a bar of 50x50 mm.

Shed roof schemes

What properties of shed roofs make them attractive in the eyes of potential builders?

Firstly, the construction of a shed is the most budget option of the possible types of roofs. The consumption of wood for its construction is almost 3 times less than for a gable roof. This factor is of particular importance in the southern treeless regions of Russia, where timber is expensive and scarce.
Secondly, roofs with a slight slope experience less wind loads due to low windage. The absence of an attic gives the room an additional volume that can be used with great efficiency. The possibility of using non-standard approaches and original design solutions has made projects of houses with a shed roof in demand.

As for all kinds of household buildings, garages, warehouses, a shed roof has been chosen for their construction for more than a century.

Photo: shed roof rafter schemes

Each roofing material has a specified minimum roof pitch:

bituminous roll materials ≥ 5 degrees;
metal tile ≥ 25 degrees;
shingles ≥ 20 degrees
slate ≥ 20 degrees;
corrugated board ≥ 20 degrees;
tiles natural or cement ≥ 35 degrees;
areas with high humidity and heavy snow cover ≥ 40 degrees.

Don't forget that the most efficient shed roof is a ventilated design.

A ventilated under-roof space with regular air exchange prolongs the life of the building, prevents the formation of condensate.

Roofing material is chosen according to your taste, focusing on the nature of the building.

If you are not sure that you can independently calculate the rafters of a shed roof and correctly fasten the rafters of a shed roof to the supports, seek the advice of professionals.

Remember that the fastening of the roof to the house must be not only strong, but also movable, “sliding”. A properly executed roof will always protect you from bad weather.

Do-it-yourself shed roof

Given the low complexity of the design, a shed roof is often taken to be done independently. You need to start with calculations of the angle of inclination, the main parameter of the roof. A large slope ensures a good runoff of rainwater and a quick release of the roof from snow in the spring. However, the wind load on the roof structures also increases.

When choosing a small angle of inclination of the roof, the windage decreases, but the risk of snow accumulation and leaks increases. All this should be taken into account in the calculations. And more importantly, what you prefer: spending money, shoveling snow or spending your free time patching the roof.

The choice of roofing is also important:

For a profiled sheet, the slope should be more than 20 degrees. Otherwise, the mass of snow can push through the coating.
For metal tiles - at least 25 degrees to reduce the load on the crate and rafters. When the angle of inclination is calculated, it is possible to calculate the difference in the height of the walls, which will provide this inclination.

The frequency of the rafters and the step of the crate depend on the material you choose and its weight. The frame of the rafters must be made only from sanded wood of air-dry moisture. In addition, all wood parts must be impregnated with antiseptics and fire retardants.

All parts are treated with fire-fighting and bioprotective compounds in advance, before installation, and only then the rafters are assembled. Often, additional processing of joints and tie-ins on the roof is carried out at the place of work.

Having completed the complete assembly of the rafters and lathing, proceed to the roofing device:

waterproofing layer. Provides maintenance in a dry condition of wood and prolongs service life of rafters;
The laying of the roof covering begins with the eaves of the rafters, moving towards the ridge. Each subsequent row of material is laid “overlapped” on the previous one, strictly maintaining the required overlap;
In the process of work, it is necessary to constantly check the tightness of the elements to each other and their tightness.

Now you probably know everything about rafters and how to make a roof with your own hands.

Shed roof rafters (photo): accurate calculation, device diagram, angle of inclination of the rafters

The article “Shed roof rafters” will tell you about the basics of calculating the structure and the angle of inclination of the roof truss system, as well as explain the rafter scheme.

Shed roof truss system: device rules and analysis of typical options

Shed roofs are quite reasonably classified as the most simple and economical structures. It attracts with minimal material consumption and a simple construction process. The construction of a single-pitched variant can be the first confident step towards an independent roofer. However, without observing the technological requirements, there will be no positive outcome even in an elementary matter. In order for the result to please with reliability, you need to know what the shed roof truss system is and what requirements must be taken into account during its construction.

One slope in low-rise construction

Shed roofs are a faithful companion of household buildings, terraces, garages, attached and detached verandas. So far, they are being built extremely rarely over residential buildings in the expanses of the fatherland, although the number of adherents of modern and high-tech styles is touching with an upward trend.

Despite belonging to the pitched category, shed roofs still cannot be unconditionally called attic: the space under the roof is too small to organize the premises. And since it does not make sense to use the attic, then it is not always advisable to separate it from the building with an overlap. Therefore, in practice, the builders of shed roofs often install spacers and rafter legs instead of overlapping.

Simplistically, the truss frame of a shed roof can be called an overlap laid at an angle or half a layered system, which is much closer to the constructive essence. It is built exclusively from layered rafter legs, i.e. from rafters with reliable supports for the upper and lower heels.

Among the options for supporting the rafter legs of shed roofs are:

Two bearing brick, concrete, wooden walls of different heights. In this case, the rafters of a shed roof rest on the walls through a mauerlat laid in two unconnected strips. Support can be made through a reinforced concrete belt, pre-designed and arranged during the construction of the walls, as well as through the upper rows of timber or log boxes.
One load-bearing wall made of concrete, wood, brick and supports located opposite. It is clear that extensions and sheds are built in this way. The upper edges of the rafters in such cases are supported by steel brackets screwed to the load-bearing wall or to sockets selected in it. The lower heels rest on a harness connecting the support posts.
Two rows of concrete, brick, wooden supports. Both heels of the rafters rest on the harness. Moreover, the supports can simultaneously serve as elements for fastening the skin and forming frame walls.

In private construction, shed structures are most often used if the span they cover does not exceed 4.5 m. Overlapping a more serious span is quite realistic: for its implementation, you will simply need to strengthen the system with girders, supports, struts.

However, among private owners there are few lovers of such large-scale shed roofs, therefore we will consider the simplest representatives and the principles of their construction. Having dealt with their design, it will be possible to create your own project by upgrading and making additions.

A well-designed project takes into account the need to have a lone slope on the windward side so that the roof is not torn off and carried away by gusty winds.

The average size of the components

For the manufacture of layered rafters, wood and lumber of the 2nd grade are used. Skinned logs will do, plates - the same logs, but hewn on both sides. Timber and pairwise sewn boards are used.

The cross section of the rafter legs for the construction of shed roofs over buildings must be calculated taking into account the weight of the roof, snow and wind loads. The listed values among folk craftsmen are simply added up and entered into one of the many calculation programs, of which there are a little less than a legion on the Internet. In order not to toil with the calculations, we will give the average statistical sections of the rafter legs and related elements used for the construction of shed roofs in the middle lane, these are:

Logs and plates hewn from them Ø 180-200mm, timber 100 × 150mm (150 × 150mm) are used for the construction of a truss frame covering a span of 4.5 m or more.
Logs and plates Ø 120-180mm, timber 100 × 100mm are used if it is necessary to cover a span of up to 4.5m.

In both cases, it is permissible to replace the beam with a pair of sewn boards, the dimensions of which will ultimately allow obtaining a beam of the required section.

It should be remembered that a log Ø less than 120mm, plates with a thickness of less than 70mm and boards with a section of less than 40 × 150mm are not used in the construction of roof structures. Even for low-responsibility canopies arranged on sites in the middle lane, the indicated dimensions are the minimum.

If the scheme of the truss system of a shed roof predetermines the run device, it is installed parallel to the slopes. It is needed to increase the rigidity of the structure as an additional support system. To fix the run, the supports and the bed are mounted in the same way as the technology for constructing gable roofs dictates. Only the goal is not to form a ridge fracture, but to maintain the plane of a large slope. The purlins of large-span structures are made from a bar 180 × 180mm or from a log Ø 200-260mm. For the manufacture of racks for runs, they take a beam with a side of 120mm or a log 130-200mm in diameter.

Single pitch truss system

The installation step of the rafter legs is determined in accordance with the geometric data of the equipped box. The slopes on which the rafters are to be supported are divided into equal sections so that the distance between the rafters is the same. The breakdown of the slopes for their installation is carried out, taking into account the size and type of materials used:

For rafter legs made of timber, log plates, installation step from 1.5m to 2m.
If the rafters are made of a paired board, the installation step is from 1m to 1.75m.
For rafters from a single board, the installation step is from 0.6m to 1.2m.

The choice of the installation step of the rafter legs of the insulated roof structure is influenced by the size of the insulation. It is very convenient if the thermal insulation boards are installed rigidly between the rafters, with slight squeezing. This is a very economical solution, because they do not need to be laid in two layers, and heat losses are excluded due to the elimination of the causes of the formation of cold bridges.

Do not forget that with an increase in the recommended distance between the rafters, you will have to reduce the installation step of the crate or even make it solid. Such a choice is not always appropriate in terms of both labor and construction costs. It is better to adhere to technological recommendations and calculate in advance which is more profitable: install one or two less rafters or strengthen the slope sheathing.

As is customary in the construction of pitched roofs, the rafters are attached to crutches driven into a wooden wall or corks with anchors embedded in brickwork. Fixation is made through one rafter leg with twists of annealed wire. The attachment points of the rafter legs to the walls are located 20-30 cm below the Mauerlat. Wire strands can be laid during bricklaying. It is allowed to fasten with brackets to walls made of timber or logs.

Variants of single-pitched truss frames

In order to better assimilate the information, we will analyze several common examples of the construction of truss systems for shed roofs. Consider simple construction projects that a skilled owner can handle.

Construction # 1 - single-pitched garage truss frame

Let's disassemble the device of the truss frame of a shed roof over the garage, the walls of which are made of foam concrete blocks. The reinforced belt recommended by the standards was not filled in, which is why the Mauerlat laying procedure is ahead. In shed roof structures, it is constructed in the form of two beams laid on walls of different heights.

The process of building a truss system in stages:

Flush with the inner planes of the high and low walls, we lay a beam 100 × 150mm. This is a shed roof Mauerlat. Because the beam will have to be in contact with foam concrete, it is laid on a roofing felt or similar waterproofing gasket. We fasten the beam after about 80 cm with roofing corners 90 × 90, reinforced with a cast jumper. We screw the corners with dowels Ø 14mm.
From a board with a section of 50 × 200 mm, we will make a rafter template. Install it on the Mauerlat so that there is a margin of about 55-60cm on both sides. The stock should be slightly larger than the planned width of the cornice overhangs. Usually it is 40-50 cm. We cut off the excess after installing all the rafters.
We mark the points of future cuts on the installed workpiece, not forgetting that the depth of the cut should be no more than 1/3 of the width of the board.
We mark the walls so that the extreme rafters on both sides do not touch the concrete wall. It is desirable that there is a distance of 4-5 cm between wood and concrete.
According to the template, we make rafter legs, install them and fasten them to the Mauerlat with brackets or corners.
From trimming the board we make a filly template, taking into account the width of the overhang. We make all cornice elements according to the template. Then we mount, not forgetting the waterproofing pads between the wooden parts and the concrete wall.
We cut off the excess rafters and nail a wind board with a section of 25 × 100 mm along the perimeter.

The elementary truss structure for the garage is ready. It remains to fill the crate under the shed roof covering the installed rafters. It can be continuous or sparse. The installation step of sparse gratings depends on the type of roofing material.

In the first example, we formed the cornice overhangs by mounting fillies. There is a slightly different way, according to which the Mauerlat beams are installed with the removal of the perimeter of the box. Removal is equal to the width of the cornice overhang. The rafters are positioned so that the extreme elements are just above the edges of the Mauerlat. In the space between the extreme and adjacent rafters, short extensions are mounted. Further, everything is according to the standard plan.

Structure #2 - shed roof over extension

No less often than the previous example, the task of building an extension to an existing building arises. For obvious reasons, the roof will be shed. It will perfectly fit into any architectural and landscape conditions, moreover, it will not create a threat of accumulation of precipitation.

The truss system is being built at an angle of 20º, because a metal tile will be installed on top of it. The rafters will rest on the main and opposite brick wall of the extension. In our proposed example of a single-slope structure, it is necessary to cover a span of 4.75 m, which is more than 3.5 m. So, to ensure rigidity, the installation of struts will be required. The design and installation of struts are carried out with the condition that their inclination angle is not desirable to exceed 45º.

The cross section of the board for the manufacture of rafter legs is 50 × 200 mm. They will be installed after 70cm. We will make the struts from a board 50 × 150mm, and for the construction of the crate we will stock up on a board 25 × 100mm.

Algorithm for the construction of a single-pitched truss frame:

We install a beam 100 × 150mm flush with the inner plane of the extension wall, not forgetting to pre-lay waterproofing. We fix the beam with bolts through 80-100mm.
In the main wall at the planned height, we hollow out the grooves for the installation of the upper heels of the rafters. The depth of the grooves is 12 cm, the width is slightly greater than the thickness of the board, the step is 70 cm. Instead of slotted grooves, you can use metal brackets that are simply screwed to the wall. In shape, they resemble an inverted letter "P", in which the upper edge of the rafters is located.
Let's make a template for rafter legs. We put the board 50 × 200mm to the place intended for it and mark the cuts from both edges. The depth of the upper cut required to install the rafter into the groove is 10 cm. You don’t need to do it deeper, otherwise the rafter will rest against the wall, and this is undesirable. The dimensions of the upper gash are transferred to the bottom. At the same time, we mark the vertical saw cut line along the width of the eaves.
Using the template, we make all the rafter legs and install them in their proper places. For fastening at the top, we use metal corners, one side of which is screwed to the wall, the other to the rafters. At the bottom we fix with corners or staples.
We try on a piece of board to the main wall and one of the rafter legs to determine the point of cutting the groove under the strut. Do not forget that the angle between the wall and the strut should not exceed 45º, and the lower heel of the strut should rest against the wall 20-30 cm below the opposite wall.
Stepping back from the imaginary vertical line drawn through the upper groove, 5-6 cm in any direction, we hollow out the bottom row of grooves. We place them every 70cm.
We cut the lower corner from the strut blank so that the cut line is 10 cm.
We try on the workpiece by setting the edge with a gash in the lower groove. Along the line of intersection of the rafter leg and the workpiece, we draw the upper washed down.
According to the verified scheme, we make and install all the struts. We fasten them to the rafters with metal gear plates.
We form cornices by installing fillies on the inclined walls of the extension. Do not forget about the mandatory waterproofing between the brick or concrete wall and the roof elements made of wood.
We sheathe the perimeter with a wind board and mount the crate.

The technology given as an example is valid not only for shed roofs over capital outbuildings. Covered verandas with terraces, utility blocks are equipped in a similar way.

Work progresses much more cheerfully if the walls of the main building are made of timber, logs or made according to the Canadian frame method. Brackets are tritely installed under the upper heels of the rafters: there is less trouble and the process moves much faster.

Structure #3 - Shed Structure for Shed

Shed roof - an excellent option for arranging outbuildings, makeshift houses, summer kitchens. Rare units need the fundamental nature of such structures. The simplest options are more actively in demand, with the construction of which the owner of a suburban area can easily handle.

Consider the construction of a shed roof over a small shed for storing country equipment. Its walls are built according to the frame-hothouse principle by installing vertical racks connected at the bottom along the perimeter with a strapping. The front and rear walls of the barn differ in height, so they are connected not by a single strapping, but by separate transverse strips.

The crossbar of the high wall is laid at an angle, which makes it possible not to make cuts to support the upper heels of the rafters. To form an angle, the high wall posts are sawn from above at the projected angle.

The algorithm for the device of the truss system is typical. First, a piece of board is applied to the end of the building and cut lines are outlined. Then, according to the template, the required number of rafter legs is sawn. They are installed in the traditional way according to the markings made in advance on the walls. To fasten the elements of the truss system over light household buildings, nails or self-tapping screws are enough. Screw or hammer hardware products at an angle, trying to ensure that there are no gaps between the parts to be joined.

The wind board is fastened around the perimeter after the wall cladding is installed. The example barn has no eaves. However, if desired, they can be made by setting the rafters with a length that takes into account the formation of overhangs. It is planned to lay a soft roof, under which a continuous crate is arranged. The dimensions of the crate made of plywood, GVLV, boards or OSB-3 are determined by the outer plane of the windboard.

The angle of inclination is small, so the use of waterproofing is highly desirable even if the items stored in the barn are not too worried about getting wet. Waterproofing will protect the wooden parts of the building from rotting and subsequent inevitable failure.

Shed roof truss system: device, diagram, instructions

Device rules, typical schemes and technological principles, according to which the shed roof truss system is built, guarantee an excellent result.

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Shed roof truss system: device rules and analysis of typical options. Shed roof rafter system: use a calculator to calculate the rafter system How to attach rafters to shed roof beams

Advantages and features of a single-slope system

System calculation

Section selection

Beam pitch selection

Tilt angle

Work order

Shed roof truss system: device and fastening

Benefits of a pitched roof

Garage roof rafter installation scheme

How to install a shed roof truss system - rafter installation guide

Roofs with one slope for low-rise construction

Approximate parameters of shed roof elements

The distance between the rafters of a pitched roof

Fastening rafters for a pitched garage roof

Installation of a single-pitched truss system over an extension

How to fix a shed truss system over a barn

Shed roof truss system

Rafter frame single-pitched design: installation nuances and elements

Advantages of a pitched roof

How is the angle of inclination determined?

Preparation of lumber before installation

Stages of installation of the truss system

No. 1: Support at the top and articulated bottom

No. 2: Top and bottom are hinged-fixed

No. 3: Free top and hinged bottom

No. 4: Mobility of both mounts

No. 5: Rigid attachment to the sloped harness

Final fixing work

Video for a visual study of the process

Why single-sided

Design calculation

Create a ramp angle

Determine the side of the roof slope

The steepness of the slopes

Mounting

The construction of rafters with a pitched roof

Rafter pitch

The nuances of mounting the Mauerlat

Floor beams, their installation

An example of a shed garage design

Scope of application and design flaws

The choice of truss system

Work instructions

Mauerlat laying

Installation of rafters step by step

Lathing and finish

Conclusion

Benefits of a pitched roof

Garage roof rafter installation scheme

Fastening the rafters of a shed roof: a thorough analysis of the units used

Traditional "wooden" troubles

Details about the knots of a pitched roof

Shed roof rafters: details and installation details

Shed roof rafters

Shed roof schemes

Do-it-yourself shed roof

Shed roof truss system: device rules and analysis of typical options

One slope in low-rise construction

Variants of single-pitched truss frames

What else to read

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