How to make a gable roof truss system with your own hands. We make rafters for a gable roof How to make roof rafters

Ideally, entrust the installation of the roof to professionals, if you decide to do the work yourself, then there must be at least one person who is familiar with this business firsthand. Also, do not immediately proceed to complex forms of construction, no matter how attractive it may seem to you. It is better to try your hand at installing simple gable roofs, with a minimum number of valleys and complex elements, because even the masters of their craft do not always succeed.

Tools for mounting the truss system

First of all, for high-quality work, you need to stock up on the necessary tools. It does not have to be from the category of a professional, but the convenience and speed of installation will depend on the completeness of the set. For the device of the truss system you will need:

Hammers, different types and weights;

Nail puller;

Pencil, marker for marking;

Center punch, with which it is very easy to punch points for drilling technical holes;

• Hacksaws or a chainsaw for woodworking (cutting blanks to size, at a certain angle and technological recesses);

  Roulette, for measurement accuracy, its face value must be no less than the size of the longest roof element, rafter leg or ridge run;

  Drill with a set of drills and a countersink;

  Bulgarian;

  Level, plumb;

Also, for ease of installation, other devices are used that are made independently, these are “thorns”, templates, etc. The "thorn" (Fig. 1) is used as a stop when setting the rafter sector to a vertical position. It is a piece of timber with a section of 6x6 cm, on both sides of which a metal corner 40x40 mm is nailed. It is cut in such a way that as a result two sharp ends are formed, with their help a safe lifting of the structure is ensured and any kind of slipping is excluded.

Another mechanism that can be useful when installing rafters is insurance (Fig. 2). It is easy to build it from a cable lift and a hoist. With the help of a simple device, you can adjust the length of the outlet and prevent the structure from tipping over in the opposite direction. The length of the safety rope must be adjusted in advance, before lifting.

Templates (Fig. 3) serve as an auxiliary measuring tool. Through them, corners are beaten off, truss sections are assembled on the ground and the distance between the frame elements is controlled.

Rice. 1 Fig. 2

The workpiece construction details are impressive, rafter boards are required

The installation of rafters begins with the study of the drawings and the selection of the main dimensions of the rafter legs, girders and other details, this is required so that, in the manufacture of blanks, the cutting of lumber is rational and economical. In some cases, when the overall dimensions of the house are lengthened. Not only must the joints be strong and secure, but the recommended location of the joint is at least 1 m from any edge of the rafter and no more than 1/3 of its length. It is not advisable to make it in the middle, from two equal parts, this reduces the bearing capacity of the elements.

Boards can be extended by overlapping and through overlays. In the first case, technical holes for bolts are made on the docking board, the recommended location: the initial holes are drilled 50 - 100 mm from the end of the workpiece, this will prevent warping of the wood. The rest are drilled in a checkerboard pattern at a distance of 80 - 100 mm from each other, this will eliminate the appearance of cracks.

In the second option, to lengthen the workpiece, wooden slips are used, which are nailed on both sides of the joint of two parts, thereby providing a rigid connection.

We also prepare in advance struts, crossbars, girders and other details according to the project documentation. In order to eliminate miscalculations, it is necessary to measure the size of the elements with a small margin, which is easily corrected in place. It is worth knowing about one more thing. Before starting installation, you need to carefully measure the geometry of the Mauerlat (support beam). For this, the length, width, squareness of the corners, the difference in diagonals are checked, the last parameter should not exceed 20 mm. The level breaks through the flatness of the base. If all values ​​are within acceptable limits, then you can safely stamp all sections of the rafters according to a single template, otherwise, you will have to customize each element individually.

Assembly and installation of the truss structure

Initially, you need to decide on the place of assembly of the rafter segments. It can be produced on the ground, but in this case it will be necessary to understand the entire structure upstairs, which is not very convenient and expedient. A good option is to assemble the rafters in place, it is possible when the floor surface allows it. All elements rise to a height separately, which is much simpler and easier.

When assembling, we lay out all the parts as they should be and fit each other (Fig. 4). In the upper part of the rafters, we fasten the plank overlay with a nail fight, and then we additionally fasten the legs with small crossbars. At least five nails are stuffed into each connection. In the lower part, where the legs rest on the puff, we fasten temporary straps (Fig. 5) so that when lifting the leg does not slip off the puff. But the supporting elements of the structure are connected by permanent bolt fasteners with metal strips on both sides.

An inch board is often used as crossbars; it is sewn with nails on both sides of the structure. After the assembly of one section is completed, the structure is set to a vertical position.

To simplify the lifting process, it is divided into several stages. At the beginning, the rafters are raised at an angle of 25 - 300, in order to make it convenient to nail the upper cross member on the other side of the assembly. At the second stage of lifting, the structure is lifted by means of insurance and fixed with the help of a “thorn” at an angle of 55 - 600, in this position the second crossbar board is nailed, just like the first one before (Fig. 6). At the final stage, the truss section is set to a vertical position, the reference point for the correct position is the plumb line attached to the crossbar. When the verticality of the structure is reached, we fix the assembly with a board. The sequence of subsequent actions has several variations.

In one case, two truss sections are exposed along the ends of the building, a cord is stretched between them, and the entire structure is assembled along it.

At the same time, auxiliary elements, various supports, linings are very actively used, which help to fix the individual parts of the truss system in the desired position. Temporary structures are not removed until the final installation is completed.

The installation of rafters can be in a different scenario, it is more suitable for those who decide to assemble the sections in place. The main difficulty lies in the fact that as the roof is erected, the space for connecting the elements decreases very quickly. But this problem also has a solution. At the beginning, rafters are installed over half of the house, five to ten pieces, depending on the size of the roof.

We collect the second half of the total number of rafters and lean them close to those already mounted (Fig. 7). Then the extreme section is exposed on the opposite side, and then we move apart and install the remaining rafter assemblies. It is not particularly difficult to move them, because when tilted they hang on the upper run and are not able to fall. This option for installing a truss system has become very popular among developers. It captivates with simplicity and ease of implementation of many projects.

It is worth focusing on one more detail, since the structures are mainly made of lumber, it is necessary to take into account the fact that the tree shrinks over time. Therefore, it is strongly recommended that a sliding fastening element be used in the intermediate part of the support of the rafters (Fig. 8), among themselves the builders call it a “slipper”. "Slipper" is installed strictly perpendicular to the rafters. Initially, the element is installed in the most extreme position, so that during the shrinkage of the house, the rafters have free play.

Upon completion of the installation of the truss system, proceed to the next stage - to the crate of the structure.

Is it time to install the roof? The very first thing you need to do is the installation of the truss system. This work is very important and difficult, and therefore it is necessary to carefully read our advice.

A bit of theory - what you need to know about the truss system?

First of all, you need to talk about the types of truss systems and their characteristics. So, this system consists of the following elements:

• rafter legs;
• racks and vertical supports;
• struts;
• puffs - an element that connects the rafter legs.

You should also distinguish between rafters by type. Rafter systems are divided into:

• Layered. They should be used if the building has internal partitions or other supports. In this case, the "legs" of the structure must rest on both the outer walls and the inner ones.
• Hanging - in which the "legs" of the structure rest only on the outer walls. A distinctive feature of this design is that for its design it is necessary to tighten due to high spacer loads.

Several important technical specifications

When choosing a method for installing rafters, it is necessary to assess the complexity of the work and the weight of the future structure. If the assembled product is lightweight or you can bring special lifting equipment to the site, then it is best to assemble the rafters on the ground, and then lift them to the roof of the building, where you can do all the other work. If the structure is characterized by a large weight, then it will have to be assembled directly on the roof - this is easier and safer.

It is very important to correctly connect the upper parts of the rafters. This work can be done in several ways. First of all, end-to-end, when cuts are made at the required angle on opposite rafter legs. Next, the rafters need to be docked along the ends obtained and secured to several nails. For a more secure connection, secure the products with a metal strap.

It is possible to fasten the rafter legs with an overlap - in this case, the structural elements are in contact with each other by planes. If you are going to make a rafter system in a house with fronts that are made of logs, then the rafters must be placed on the walls using the sliding fastener method. Thanks to this, you will be able to avoid deformation of the roof in case of shrinkage of the house.

If you decide to use this method, then you need to consider that it is quite difficult to do it yourself. Fasteners are made as follows: the "legs" of the rafters must be placed with a gap, fastening them together using a specialized movable metal element. Now we proceed to the direct construction of the truss system with our own hands.

Mauerlat - what is it and why?

The construction of the rafter system must begin with the installation of a Mauerlat - these are the foundations for the future design. Mauerlat is a log or beam, which is attached around the entire perimeter of the outer walls. Undoubtedly, it is possible to make a structure without a Mauerlat, but it will be quite difficult and even risky to build such a structure with your own hands. It is very important to follow all the recommendations exactly so that the base for the truss system performs its functions 100%.

Important Tips:

• Before laying the mauerlat, the walls must be insulated with a suitable waterproof material. To save money, you can put several layers of roofing material.
• Installation of logs is carried out on a reinforced belt with a small indent from the edges of the walls.
• It is best to choose logs of antiseptic wood with a section of 10 * 15 cm.

For the convenience of doing work with your own hands, the bars must first be laid out from one front to the other along the entire length of the wall. After that, you can take measurements: lay out the bars according to the level, watching the evenness of the distance between them. Next, you can attach the bars to the walls. As we have already said, it is preferable to carry out installation on a reinforced belt, using anchor bolts as a fastening product - it is better to fasten them when pouring a reinforced belt. Also do not forget to drill holes in the beam itself.

Important: if you want to achieve a perfectly even position of the bolts, before pouring the “belt”, attach the board to the bolts and give the fasteners a vertical position using a square.

We put the base prepared with our own hands on stands consisting of planks, after which we carefully lower the bars onto the bolts, each time taking out a plank. At the end, we wind the washer to the bolt. Now it's time to learn how to make a truss system with your own hands.

Do-it-yourself installation of a truss system

We have already talked about the installation of the Mauerlat. Now it's time to move on to the main point of installing the truss system - this is the installation of floor beams and a ridge beam. But first things first. Floor beams - beams with a section of 20 * 10 or 15 * 10 cm. The length of the products should be such that, when laid on the walls, the beams form an extension that will correspond to the width of the eaves.

In simple words, the bars should go beyond the walls at a certain distance. The bars are installed in one direction, leaving an equal distance between them.

To ensure that there are no errors during the execution of work, a clear sequence of actions should be followed:

• We mount the boards with our own hands, retreating from the edge of the walls by an average of half a meter.
• We stretch the cord between the bars - it will serve as a kind of "beacon" for the installation of the following beams.
• The distance between the "legs" of the structure must be chosen based on the section of the rafters. So, if you decide to choose "floor" boards, 5 * 15 cm in size, then the step should be approximately 60 cm. It is worth noting that this will greatly simplify all further work. And all due to the fact that the width is most often 60 cm, which means that nothing will need to be trimmed.
• We proceed to the installation of transverse bars, which in one part should be in contact with the extreme beam, and the second - go beyond the walls. The gap between such jumpers should be about 1 m.
• We attract the beams to the base (Mauerlat) with the help of nails, you can also use self-tapping screws and steel corners (for reliability).

To make it as convenient as possible for you to carry out work during the construction of the truss system with your own hands, lay ordinary boards on the beams.

Now it's time to talk about installing a ridge beam. This stage consists of several steps:

• Installation of auxiliary racks, which are U-shaped struts made of wood. Professional experts advise that the height of the spacers be equal to the height of the first floor.
• We assemble racks at opposite ends of the structure and put intermediate beams, maintaining a step of 2.5 meters.
• After mounting the racks, we lay a ridge beam on top (a wooden board with a section of 5 * 20 cm). Fix the structure with self-tapping screws.

Since the rafters must have the same length, it is advisable to make a template in advance to determine the length. To do this, we take one board measuring 2.5 * 15 cm, apply it to the beam and to the ridge, and put marks at the points of contact and saw off the unnecessary part - you can make blanks using this template. True, it is worth noting that not everyone can achieve perfect evenness, and therefore get ready for the fact that during the installation process you will have to use the saw more than once.

If you neglect this advice, then the skate may bend, which may make the design not so reliable.

After you have installed the truss system, you need to make waterproofing, create a crate and cover the structure with roofing material. Now you know how to assemble the truss system - the roof is almost ready. We hope our tips will help even you to do the work yourself.

The basis of a beautiful and reliable roof is a solid construction of the truss system. It is important to mount it in such a way that it will serve for many years, especially in difficult places of contact with the walls of the building, chimneys and pipes of the ventilation system. Depending on the weight of the snow, the wind load and the severity of the roof, it is necessary to choose the correct pitch of the rafters and the layout of the articulation nodes of the individual elements of the rafter group. We will consider options for attaching parts of the structure to floor beams and ridges, ways to increase the load capacity of rafter legs and step-by-step installation of trusses and a complex roof as a whole.

The device of the truss system

The construction of the roof is the final stage in the construction of the house, it determines the degree of protection of the building from atmospheric influences and the appearance of the entire building as a whole. The roof frame, on which the roof and insulation are mounted, is called the truss system. The device of the rafter group depends on the type of roof and its complexity, on climatic conditions and on the purpose of the attic. It is mounted on a Mauerlat, fixed on the walls of the house along the perimeter, and consists of the following elements:

• floor beam or puff - a horizontal beam based on a Mauerlat;
• hanging or layered rafter legs, which are attached at the bottom to a puff or Mauerlat, and at the top they are connected and form a ridge;
• run - a beam connecting the trusses of the truss group;

  Depending on the type and size of the roof, truss systems are layered, hanging or combined, but their main elements are largely the same.

• racks, crossbars, struts and contractions are auxiliary elements that are necessary to give strength to the rafters and the entire roof structure;
• sprigs - used on hip roofs and are shortened rafters;

  The diagonal rafters of the hip roof are fastened with sprenels and trusses to ensure even distribution of the load.

• sprengels - designed to give strength to the diagonal rafters of the hip roof;
• filly - are used to lengthen the rafters and sprigs and form a cornice overhang;
• frontal boards - are attached to vertically cut rafters or filly and serve for mounting droppers, wind slats and brackets of the drainage system;
• counter-lattice - mounted on the rafters and used to create a ventilation gap between the waterproofing layer and the roofing material;
• crate - stuffed perpendicular to the counter-crate and serves to fasten the roofing material.

More complex types of roofs are formed from a combination of pitched, hipped and hip types, their truss system is also assembled from the described elements.

The basis of any system of rafters and trusses is a rigid triangular connection, which gives strength to the roof structure and allows it to withstand the weight of snow and wind.

Rafter device options

The rafter system of any kind is designed to create inclined pitched surfaces from which precipitation flows down without accumulating on the roof. In addition, the sloped surface better resists multidirectional wind loads. When installing a truss system, the following types of rafters can be used:

From these types of rafters, different types of roofs are assembled. Consider the most popular options for the device of pitched systems of various configurations.

Shed roofs are used in the construction of country houses, garages, baths and utility rooms. Such roofs are made using the simplest truss system, which can become more complicated with increasing slope length. If the distance between the walls of the building is more than 4.5 m, then the rafter legs are reinforced with struts. For spans of more than 6 m, it is necessary to use two rafter legs on each side or install an additional vertical stand with symmetrical slopes.

The choice of the design of a single-pitched truss system depends on the length of the slope, while the use of composite beams is allowed

As the length of the slope increases, the design of the truss system becomes more complicated with rigid triangular elements and contractions, which gives it additional strength.

Based on the experience of the author of this article, for soft roofing materials with small slope angles, it is necessary to use a solid plywood crate with a thickness of 12 mm or more. When sheet roofing material is used, the sheathing step should be reduced to 10 cm, the overlap should be increased to 15 cm, and the joints of the sheets should be additionally sealed.

Gable and broken attic structures

The gable type of roofs, traditional for the entire territory of our country, remains popular today. This is facilitated by the simplicity and reliability of the truss system, as well as the ability to equip a cold or inhabited attic. As a rule, a gable roof with an attic is formed by hanging rafters without an average support, and its rigidity is provided by crossbars and side posts, which serve as the walls and ceiling of the attic room.

Gable and broken mansard roofs are very popular in suburban construction due to the ability to equip an additional residential under-roof space.

Broken gable roofs are distinguished by the largest volume of the built-in attic, the frame system here is represented by a combination of hanging and layered rafters with different slope angles.

Gable truss systems are characterized by simplicity of design, high strength and minimal consumption of building materials; such roofs are often used in budget summer cottage construction.

Four-pitched rafter systems

Four-pitched roofs are formed by two trapezoidal and two triangular slopes and have a complex structure of the truss system with a supporting frame on which row and diagonal beams are mounted. The space between the rafter joists is filled with spears, and the truss resting on the corner lintels serve as an additional support for the diagonal legs.

Four-slope truss systems are typical for hip and half-hip roofs, under which you can place a spacious attic room

Four-pitched roofs are perfectly protected from multidirectional gusts of wind and give the building a special chic, but their disadvantage is an expensive and difficult to install truss system.

The basis for the truss system of the half-hip roof is the walls of the building, on which the Mauerlat, girders and longitudinal trusses are located.

The truss group of a semi-hip roof, as a rule, rests on the side and front walls of the building and has a slightly different design with truncated triangular slopes.

The device of the supporting frame of hipped roofs

The rafters of hipped roofs in the upper part converge at one point and form a multifaceted pyramid. To increase the strength of the connection of the rafter legs, special docking elements, sheathing bars and additional sprigs are used.

The rafters of the tent system converge at the top at one point and are fastened together with ties, in the lower part they are fixed with cuts

Hipped roofs give the structure a unique look, but are characterized by an increased consumption of roofing and lumber. Most often they are used on outbuildings, gazebos, and in a truncated version - as bay window roofs.

Multi-gable truss groups

Multi-gable roofs are pitched fragments cut at right angles to each other and forming internal corners or valleys at the junction. The rafters of such a roof have different lengths, and the assembly of this structure requires professional skills, since the size and angle of inclination of the slopes may differ from each other.

The truss system of a multi-gable roof forms eight triangular slopes, at the junction of which there are valleys

Roofs of this type are designed to provide natural light to the under-roof space and have a very attractive appearance, but they are quite difficult to install and insulate.

The passage of ventilation and chimney pipes through the roof sometimes requires the displacement of the rafter legs with a violation of the selected step between them. But if there are pipes of sufficiently large dimensions, combined into one block, this is not enough. It is necessary to cut the rafters at the place where the pipes pass and connect the cut sections with other rafters with bars fixed to the corners. The distance between the pipe and the wooden elements must correspond to a fire gap of 130–150 mm.

The rafter system around the chimney is built taking into account the fire gap, and the cutout is reinforced with additional racks

Next, the trimmed rafters are fastened with the help of vertical racks to puffs or floor beams. Thus, a box is created around the pipe, which does not come into contact with its hot surface and, if necessary, is filled with non-combustible heat-insulating material.

Roofing over old roofing

In the process of service, the roofing is subject to natural wear and tear. If there is no deformation of the old truss system and you are convinced that it will last for a long time, then repairs can be made quickly and efficiently. When there is no time to dismantle the old roof, you can lay a new coating directly on top of the old roof. To do this, you need to know exactly where the truss beams with the counter-lattice and the batten boards pass.

According to personal opinion, drawn up on the basis of practical experience, for a new roofing it is better to choose corrugated board, metal tiles or ondulin, which will not create a large load on the structures of the old roof.

Video: roof replacement without dismantling the old one

The step of the rafter legs when installing the roof

When installing the roof, the rafters are installed at a certain distance from each other. This distance is called a step. Recommendations for choosing the pitch of the truss system are set out in SNiP II-26-76 * "Roofs". The decision must be made taking into account the following parameters:

• roof type;
• the length of the slopes and the angle of inclination;
• type of roofing material;
• section of rafters;
• expected wind and snow load.

The pitch and number of rafters can be selected based on recommendations and adjusted to suit the particular roof. For simple gable roofs with cold attics, the calculation can be made based on the following table.

Table: choice of length, pitch and section of rafters

Mansard and complex roofs require a more durable truss system with more frequent trusses and a change in pitch at butt sections with different types of slopes. On such roofs, a beam with a section of 50X150 and 100X200 mm serves as rafters, and the pitch is selected in the range from 60 to 120 cm.

In the construction of roofs with a habitable attic room, a beam of a larger section is selected, and rafters are installed more often to increase the strength of the truss

According to the observations of the author of this article, the dimensions of the insulation material have an indirect effect on the choice of step. For example, the standard width of the insulation is 60 cm, and the allowable pitch of the rafters with a section of 50X150 mm on a pitched roof is in the range from 60 to 120 cm. Prudent owners choose a step multiple of 59 cm in order to mount insulation mats tightly and without gaps between the rafters.

Complex roof construction

Complex roofs include multi-level architectural solutions, which are often characterized by a mixture of styles, for example, a pitched roof with a bay window or a combination of a hip structure with a tent element. Even an ordinary multi-gable roof with gables at different levels often has a very complex truss system. The design of such systems is carried out in accordance with the requirements of SP 64.13330.2011 "Wooden structures" and SP 17.13330.2011 "Roofs". Professional specialists should be involved in design work, since even a small mistake can lead to marriage and the loss of expensive materials.

Complex roofs should be built only according to ready-made design solutions that contain all the necessary information for the selection of materials and describe the sequence of installation work

The truss system of complex roofs can be divided into simpler components, and at their junctions, valleys, vertical racks and horizontal ridge-type beams can be mounted.

When installing complex truss systems, it is important to ensure that a gap is maintained on all slopes for under-roof ventilation, otherwise condensate will damage the rafters, lathing and insulation layer.

Video: complex roofs

The nodes connecting the elements of the truss group perform the function of providing a rigid and durable fastening of parts. The assembly quality of the nodes is subject to increased requirements, since in these connections there is a uniform distribution of the load from the load-bearing elements to the puffs, floor beams and mauerlat. The main types of connections that are used during the installation of rafters include the following nodes:

There are also particularly complex connections, for example, the junction of the diagonal hip roof rafters to the purlin and the Mauerlat, or the sloping roof assembly, where five parts of the truss system are connected.

When assembling a sloping roof, special attention should be paid to the transition node of the hanging rafters to the layered ones, since five load-bearing elements are connected in them at once

Consider the attachment point for rafters, racks, girders and puffs using the example of a broken mansard roof. In it, the vertical stand is connected with a tie-in to a horizontal run and a puff, then the lower rafter leg is mounted to them, which rests on the puff with the help of a tie-in and a metal bracket. Then the upper truss truss is fastened with ridge ties and also cuts into the puff and is fixed on the bracket. In other nodes of the truss system, which are used on various types of roofs, the same principles for connecting parts are used. Nails, self-tapping screws, bolts, perforated metal strips and corners of various designs are used as fasteners.

Installation of the truss system

Before starting the construction of the truss system, it is necessary to carry out preparatory measures to ensure efficient and quick assembly. It is necessary to create a safe environment for work, prepare a place for cutting and making templates, as well as ensure the availability of lumber and fasteners. During the installation process, working drawings and the following tools will be required:

• goniometer (malka), level, construction pencil, cord;
• chain saw for rough cutting and trimming;
• circular saw, jigsaw;
• electric drill, screwdriver;
• hammer, chisels.

Before assembly, it is necessary to make templates of the same type of elements of the truss system and make sure that they fit well and fit well at the installation site.

Roof trusses must be made according to a single template, and this can be done both on the ground and directly at the work site

The final stage of the preparatory work is cutting the lumber to size, impregnating the elements with flame retardant and antiseptic compounds and natural drying for at least a day.

In the absence of design documentation for the roof, it is important to pre-select methods for attaching rafter legs to the ridge and cornice parts, as well as design solutions for connecting parts in various docking and other nodes.

The rafters are fastened to the floor beams or puffs in the lower part in various ways, depending on the complexity of the truss and the length, and therefore the weight of the rafter legs. Rafters with a length of less than 4 m and a cross section of 50X100 mm are sufficient to be attached to the beams with a plank knot or using metal plates, cutting the timber at the required angle and using surfs.

The choice of the method of attaching the rafter legs to the Mauerlat or floor beams depends on the angle of inclination of the slopes, the weight and length of the rafters, as well as on the expected external load

With large values ​​of the length and weight of the rafter legs and the expected snow and wind load, the connection must be made with a frontal cut, single or double tooth. In this case, sub-beam linings are used to ensure a snug fit of the threaded studs. Before installation, it is necessary to create templates that will ensure the correct cutting of materials at the cutting unit and the perfect fit of the elements. To avoid chipping at the edges of the floor beam, it is necessary to cut to a depth of at least 2 cm and at a distance of 1.5 h from the edge of the beam (where h is the height of the beam).

It is important that the holes for the threaded studs are located at an angle of 90 ° to the upper plane of the rafters, as this will ensure a snug fit and secure attachment of the parts to each other without displacement or distortion.

How to make cuts on truss beams

In the process of assembling the rafter system, it is necessary to join elements with different angles of inclination. Building levels and goniometric tools are used to mark cuts, cuts and corner joints, and templates are made in the mass production of the same type of parts. Washdowns on the rafters can be done in the following sequence.

1. The timber is exposed to the Mauerlat and the ridge run, vertical lines and the exact position of the tie-in are marked according to the level.
2. The angle of inclination is fixed on the bevel, and the dimensions of the insert are measured with a tape measure or square.
3. With the help of a square and a goniometer, the measurement results are transferred to the workpieces, after which the cutting angles and the dimensions of the cutting spikes are marked.
4. On the marked workpiece, the necessary cuts are made.

Places for cuts are marked in several stages using a construction pencil and goniometric tool

Diagonal rafters or rafters come to the junction at different angles in two planes, in this case, using the level, the vertical angle of the junction is marked, and then the desired junction angle is fixed with a small one and transferred to the part.

According to the author of the article, cutting the material according to a single sample is not an unnecessary operation, since the time spent on making templates is more than paid off during the installation process, which is significantly accelerated and becomes more rational and of high quality. It is necessary to pay attention to the good condition of the goniometric tool and use only proven specimens.

Do-it-yourself installation of the truss system step by step

Many owners, in order to save money, mount the roof of the house on their own. With some building experience, this decision is quite justified, since even complex roofs can be assembled with your own hands, having project documentation. In the absence of a project, it is necessary to make a drawing of the future structure yourself with the main parameters and dimensions of the elements of the truss system.

Rafter truss blanks can be assembled on the ground or directly on the roof. Usually a triangle is made from two side beams and a lower puff, all other elements are mounted after the truss is in a vertical position. Each design must be made according to a template made in advance and tested at the installation site. With a significant length and weight of structural elements, assembly is carried out in stages.

Installation is carried out in the following sequence.

1. On the threaded studs of the reinforced belt or the last crown of the walls around the perimeter, solid Mauerlat bars are mounted to ensure even distribution of the load from the rafter system to the walls of the building.

   In the houses of their concrete or building blocks, the Mauerlat is installed on studs embedded in the armored belt; in wooden buildings, the last crown of the wall usually plays its role

2. Floor beams or puffs are attached to the Mauerlat with brackets, metal corners or bolts. When using long and massive rafter legs, vertical racks are mounted in the middle of the floor beams, and ridge runs are attached to them.
3. The first blank for the roof truss is installed from one edge of the roof (on the pediment). A tie-in is made on the rafter legs, and they are attached to the Mauerlat, floor beams and ridge run.

   Roof trusses on the gables are installed first

4. The second blank is installed in place of another pediment.
5. Both farms are fixed in a vertical position, which is controlled by a level or plumb line.
6. Guide cords are pulled between the installed trusses.

   Guide cords are pulled between the truss trusses installed on the gables to control the correct position of the intermediate elements

7. Intermediate truss structures are installed with the selected step. All of them should be aligned vertically and along the stretched cords.
8. Ridge and additional horizontal runs are mounted (if they are provided for by the design).
9. The rafters are reinforced with crossbars, racks and other elements provided for by the project.

   After installing all roof trusses, horizontal girders and additional reinforcing elements are mounted

10. On hip roofs, ordinary rafters are first installed, based on a ridge run and a mauerlat, and then diagonal rafters and rafters are alternately placed.
11. With the help of gable and frontal boards, overhangs are formed that protect the walls of the building from precipitation.
12. A waterproofing film with a sag of no more than 20 mm and bars of a counter-lattice are attached to the rafters, which provide a ventilation gap between the waterproofing and the roofing. Then a longitudinal crate is laid, which serves as the basis for the roofing.
    

    Installation of a waterproofing film, counter-lattice and lathing completes the assembly of the truss system

Experience shows that with a rafter length of more than 6 m, it is necessary to build them up at the joints using a spike, double-sided pads and using threaded studs or bolts installed in increments of 15 to 20 cm. The joint must be reinforced with additional racks or struts. In 2010, using this technology, the author mounted a roof with a length of rafter legs of more than eight meters, so far no deflections or other changes in shape have been found on the slopes.

Complex roofs are mounted, starting with the main supporting structures on which the truss system is based. Then ordinary and diagonal rafter legs, sprigs and auxiliary elements are installed. In conclusion, different types of fragments are joined together into a single structure.

According to the author of this article, who mounted three roofs of varying complexity with his own hands, the installation of the truss system can and should be done by yourself. The first roof was cut and assembled according to the drawing in four days, and on the fifth and sixth day waterproofing, sheathing, frontal boards and roofing material were installed. The second roof took three and a half days, and the third was erected in two days. With the growth of skill and with proper planning of work, the installation of the truss system is significantly accelerated. If you have building experience, then installing a roof with proper quality is not difficult at all. In case of difficulties, it is necessary to involve design engineers or professional builders for advice, who will help in a difficult situation.

Video: device and installation of the truss system

We considered the options for assembling the truss system at the junction with pipes, over old roofs, at the points of contact with the Mauerlat, as well as in the case of complex truss structures. Along the way, we studied some ways to connect elements of trusses and slopes. The roof can be assembled with your own hands, it is important to strictly follow the step-by-step instructions and strictly observe safety precautions, then success will be ensured.

Installation and installation of the roof is a complex and responsible business. The main element of the roof are the rafters. Figuratively speaking, this is the skeleton of the future roof or frame. It can be made independently, while observing strict rules. A poorly made truss base will cause many problems.

Roof types

Ideally, the roof is a flat, flat surface with a certain slope or slope. In order for atmospheric precipitation to flow down on the installed roof, a building element is used - rafters. They serve as the basis for fixing the main roofing surface. Depending on the angle of inclination of the slopes, the roofs are divided into:

• pitched, if the slope is more than ten percent;
• flat, with an angle of inclination from 2.5 to 10%.

In turn, flat roofs are divided into single-pitched, gable, tented.

Single-sided are the simplest. They are laid on two walls of the building, the height of which is different. With gable roofs, the height of the walls should be the same, and the end parts of the rafters are made in the form of a triangle. When constructing a hipped roof, a structure is used that has four slopes. This is a rather rare species, and it is quite difficult to perform independently.

What you need to know when installing rafters

The rafter is the supporting structure. It must reliably hold the entire weight of the roofing material, resist gusts of wind and withstand snow loads. In this regard, when choosing a material for the manufacture of rafters, it is necessary to take into account the above factors, as well as the climate in the area where the construction is being carried out. The main elements of the rafter system are beams, in fact, rafters and Mauerlat.

Kinds

Rafters according to the method of fastening are divided into hanging and layered.

There are some special terms. A triangle of rafters is called a truss, which consists of an upper and lower chord, and a brace. A brace is an inclined beam, vertical beams inside the truss are racks. The rafter legs are called the basis. The legs serve to support the crate.

In a layered rafter system, the rafter legs do not create bursting pressure on the wall of the house. Such rafters are used when installing a roof with small spans or where intermediate support fasteners are used, in the case where there is an intermediate wall.

In all other cases, hanging variants of the truss system are used. In each case, the owner himself determines which type to use.

In the hanging version, the rafter legs work, in terms of material resistance, for compression and bending. In order to reduce the load on the wall, special puffs are used. They can be wooden or iron. They fix the legs of the rafters.

The power of the system being built directly depends on the height of the screed, and its reliability. The system is mounted for large buildings when the rafter pitch is large enough and there are no additional supports. In this case, the pressure on the Mauerlat is present only in the vertical plane.

Note! For a sloped roof, it is important that there is an intermediate wall of the building or additional supports. In this case, the ends of the slopes rest against the side walls, and the posts - against the intermediate wall or additional load-bearing supporting structures. The latter experience stress only in bending.

When planning a roof covering system with spans in several rows, a mixed combination of layered and hanging rafters is used, with their sequential alternation.

For the crate, as a rule, wooden boards are used, with the help of which a discharged base is created. You can use the bars in this capacity, laying them in two rows. The structure is fastened with nails. If a soft material is used as a roofing material - roofing material or roofing felt - the crate is made in the form of a continuous coating, without thinning. It is made for greater reliability in two rows. One row (bottom) plays the role of a working base, and the top one serves as additional protection.

Lathing with gaps is used to cover the roof with the use of asbestos-cement slabs. When using slate, tiles or fiberglass, the crate is made of beams that have cross-sectional dimensions of 50 × 50 mm.

Installation technology

It is as follows:

1. Only high-quality wood is used for the manufacture of rafters, without external defects and damage. These are, as a rule, lumber of the first or, more rarely, second grade.
2. The rafters are made using a circular saw, which performs cross cutting. Trimming is performed according to special templates. On the same machine, longitudinal cutting is also performed.
3. In order for the whole structure to be assembled in the correct order, it must be produced according to the previously outlined scheme.
4. After the preliminary work has been completed, the rafters must be numbered to avoid errors during the subsequent cycle of work.
5. Then nests are selected for installing bolts and dowels.

Rafters can be bought ready-made. Some construction organizations are engaged in these works. If material resources allow, it is better to use the factory design.

The most popular and stable version of the truss structure involves the following requirements:

• the basis of the design is a beam, which consists of several beams interconnected by means of lamellar dowels.
• dowels are made only from oak or birch;
• pins are attached only to the extreme parts, in no case to the middle;
• wood must be dry, with a permissible moisture content of not more than twenty percent.

Installation

First you need to calculate the weight of the roof. If you plan to build a roof of light construction, then you can not use the Mauerlat. It is designed to evenly distribute the concentrated load, which is transmitted by the support points of the rafters to the outer area of ​​\u200b\u200bthe outer wall. But they perform another important function - they tie the roof to the walls of the house. This is especially true in areas where the winds are constantly blowing. They are square beams, measuring 15×15 cm in cross section. They are directly laid on the surface of the walls.

The rafters are also wooden beams, but of a different section. Their thickness is 5 or 7, and their width is 15 cm. If a roof is planned from heavy material, then the rafters must be chosen larger: 8 × 20 cm. The distance between adjacent rafters is called a step. Depending on the system chosen, the step can be from half a meter to one meter.

Before starting work on the installation of rafters, it is necessary to make scaffolding. The use of stairs for these purposes is not effective and not very convenient. The most convenient option for joining rafters when this process is carried out on the ground. Then the finished structure rises to the top. There are only three mounting methods:

1. The connection is made end-to-end, the rafters are fastened with two nails per 200. To further strengthen the connection, you can use a wooden lining or a metal plate. They are fastened with screws or bolts.
2. The use of a ridge beam. Each of the rafters in this case is attached separately, without the use of templates.
3. Docking is done overlap. For this, special studs with wide washers and iron bolts are used. The last method is the most common.

First of all, the extreme rafters are mounted. A measuring rope is stretched between them, which will make the roof even. Then, with a certain step, intermediate rafter triangles are installed.

So, the rafters are installed. Now we have to connect them with beams and Mauerlat. Rafters with Mauerlat are connected with nails.

Note! There are several options for attaching rafters, which can be used depending on the design of the building and the features of the roof. If the house is stone, then the rafters can be fastened with wire to the reinforcement hammered into the wall.

Next, the crate is installed and strengthened, the main roofing material is laid. As you can see, with your own hands, such work can be done alone only for a small room: a bathhouse, a garage, a summer house, a log house. For more serious structures, experienced specialists are needed, and best of all, an integrated team.

Video

This video will help refresh the memory of the forgotten trigonometric functions, which are simply indispensable when calculating the rafter system - the angle of the rafter connection and their length:

Practical issues of installing rafters are discussed here:

The installation of rafters, as well as the creation of the entire roof, is a very important process. Taking into account that the base of the roof can be fixed to the wall using improvised means for lifting, subsequent work on its creation, which includes the installation of rafters, will be impossible without scaffolding, which also includes mobile structures. Scaffolding is used to lift materials to the desired height, in addition, they can be used as a working platform for a person and a place for laying building materials.

The device of the truss system.

Preparation of scaffolding and scaffolding

Do-it-yourself rafter installation can seem like a lot of work, but if you follow all the tips and follow them correctly, the process will be fun. If you are building a house, then you must use at least 3 scaffolds, in any case, their number should not be less than 2. For work, it is better to make mobile scaffolding, as they are very convenient. Installation of rafters should begin only after all safety issues have been resolved, in no case should this be neglected, since health is more important than construction speed.

Types of truss systems.

If there is no internal load-bearing wall in the house, that is, there is no additional support, and the construction legs rest only on the outer walls of the house, then hanging rafters should be used.

What is a rafter? Translated from the Old Russian language, this is a structure to support a gable roof. And the rafter legs are inclined, with the help of which the roof slope is formed. The rafter legs are usually connected by "grandmothers" or "fillies", which are made vertically. The puff is a horizontal beam, with its help the rafter legs are connected.

Varieties of rafter designs

Roof structures, as a rule, contain the following components:

Schemes of layered rafters and their application.

1. Rafter legs are used to form the slope.
2. To transfer part of the load - columns or internal supports.
3. Various inclined elements (braces, braces) that perform the same functions as the racks.
4. Elements that fasten rafter legs to each other. Usually floor beams are used for this.

Triangle - the optimal shape of the truss truss. This design has the highest rigidity.

Despite the many possible roof shapes, two types of rafters are commonly used:

1. Layered truss system;
2. Hanging rafters.

Figure 1. Installation of rafters.

The first case is used subject to the presence of internal load-bearing elements in the building structure. At the same time, the rafter legs have an emphasis not only on external walls, but also on internal columns or supports. Racks are used to transfer the load. Figure 1 shows the mounting schemes of the rafters.

The hanging structure has an emphasis only on the outer walls, and in the ridge the rafters rest on each other. Hanging rafters are used in the absence of intermediate supports, while the span is less than 12 m. A design feature is a high spreading load, to reduce it, special puffs are used. The legs of such a rafter system should be strengthened with struts, which will also reduce the pressure on the load-bearing walls.

Walls made of brick or stone require the installation of a Mauerlat. Mauerlat is a wooden beam, which usually has a section of 150x150 mm and is fixed with special studs. These studs must be pre-embedded into the wall. A waterproofing layer must be laid under the Mauerlat.

Do-it-yourself installation of hanging rafters on the Mauerlat: step by step instructions

For work you will need the following tools:

Scheme and installation of hanging rafters.

• axe;
• a hammer;
• knife for precise fitting of parts;
• pencil;
• plumb;
• roulette;
• building level.

To install the rafters, it is necessary to take a beam, the length of which will be 6 m, and the section 50x200 mm. It should be noted that if the cross section is suddenly small, then after some time, such a structure may sag. Based on the case described above, the roof slope, namely its angle, should be 33 º. The next step in installing the rafters is that, using scaffolding, you need to raise 2 beams and connect them at the top.

Knots of layered rafters.

1. On the rafter legs, you need to “cut the heel” in the following way so that the rafter rests well on the Mauerlat.
2. With the next rafter, you need to do the same. It will be nice if the rafter legs are marked as “left” and “right”.
3. After completing these works, the rafter legs must be connected.
4. After that, at the place where the rafter legs are connected, it is necessary to perform a “stump” with the correct angle, so that the rafters at the top are not overlapped, and then fastened with nails. This method is unreliable, as the rafters rest against each other.
5. For the correct execution of the “hemp”, one should initially attach one rafter to another, then draw a line of their connection (you can use a pencil for this) and only then saw off.
6. To prepare building material on the ground, you need to measure and make several templates at once.
7. Having done all the operations, we begin the installation of the rafters, first on one gable, and then on the other. Using nails, we fasten the rafters to the Mauerlat.
8. The following pairs of rafter legs are prepared according to ready-made patterns on the ground;
9. Then you need to pull the thread along the ridge between the already finished pairs of rafters and proceed with the installation of all the remaining rafters.
10. The distance at which the rafters are installed is 70 cm. Of course, in fact, it can be within 68-73 cm from each other. This is considered the optimal distance for the roof, as it is reliable, and such a distance between the rafters will be convenient in the future when you stretch the film.
11. For these purposes, it is necessary to initially mark the Mauerlat, and then install the rafters on it.
12. It is worth noting that the adjustment must always be carried out with the help of a thread that is pulled between the rafters, when necessary, it will be possible to adjust the height of the rafter legs on the spot. In some cases, you need to put small boards under your feet.
13. Adjustment in the lower part in width, which is between the two rafters, is made according to the indicated markings on the Mauerlat. As for the upper part, here the adjustment is carried out using a temporary board with the same markings. This means that after each pair of rafters is installed, a board is temporarily nailed to the top of the left and right rafters according to the markings already made in advance, which corresponds to the markings applied to the Mauerlat.
14. In the described case, the hanging rafters will need to be connected with a horizontal bar, that is, with a puff, due to the large distance between the supporting walls. It is worth paying attention to the fact that initially the rafter pairs were connected by a horizontal board in the area of ​​\u200b\u200bthe ridge, thus forming a ridge knot.

Gable roof installation.

In the case under consideration, due to the large distance between the bearing walls, where the width of the house itself is about 11 m, the puff will not consist of one bar, but of several interconnected boards. Such a puff, made of several boards, will help solve several problems at once:

• the result is a tightening of the desired length:
• it is worth noting that the strength and reliability of tightening made of 3 boards with a total thickness of 60 mm is much higher than if it is one beam with a thickness of 60 mm.

Quality roof: summing up

For the required length, 4 and 6 m boards were cut, after which they were fastened with nails, twisted with nuts and studs with rafter legs.

Under constant control, you need to keep the distance that is between puffs. It should be the same as that between the rafter legs.

To do this, you need to use narrow boards, as in the case of adjusting the distance of the rafter pairs at the ridge, which are marked and correspond to the markings on the Mauerlat. Always keep your distance under control!

In addition to all this, the puff and the skate were connected by another 1st board. Given the fact that there is no retaining wall, the puff will simply bend, unable to support its own weight. In order to avoid such troubles, the tightening together with the ridge of the rafter pair are connected by a “headstock”. All of the above actions must be done with each rafter pair.