How to put rafters on the roof for one person. Materials for the manufacture of rafters

During the construction of private houses, the roof is most often made gable. There are reasons for this. First, it is reliable. Handles wind and snow loads well. The second - it is compatible with any roofing. The third is relatively inexpensive. The fourth is a simple design that is difficult to spoil. Fifth - it looks attractive. All this, and also the fact that a do-it-yourself gable roof is built without special knowledge, determines its popularity.

Do-it-yourself assembled gable roof ready for installation of roofing

Step-by-step installation of a gable roof

As you saw above, there are a lot of truss systems. Accordingly, when assembling each has its own characteristics, but in general the order is the same. It is necessary to say about the general step: pre-drying and processing of wood. This step is required if you bought fresh lumber, not dried.

The use of raw wood in the construction of the roof natural humidity will lead to problems: the beams will bend, they will dry out, the geometry will change. All this will lead to the emergence of stress points and at the slightest sign of overload (a lot of snow, strong wind or rain), negative processes will begin. Their elimination is a complex and costly undertaking. Therefore, either buy dry wood (no more than 20%, ideally chamber drying 8-12%), or buy material a couple of months in advance, put it in ventilated piles. After that, treat with the necessary impregnations (from fungal attack and to reduce flammability) and only after that use it in the installation of the truss system.

Timber must be dried in ventilated stacks. To do this, they are laid in short pieces of boards. They are placed a meter from the edges and further through the meter. Spacers must be installed under the bottom

We will talk about the main stages of assembly, about how to make a gable roof with your own hands in this section.

Mauerlat

The assembly of the truss system of two pitched roof from the installation of the Mauerlat. It must be set strictly horizontally, therefore, before starting installation, the horizontalness of the wall to which it is attached is carefully checked, if necessary, it is leveled with cement mortar. You can continue work after the solution gains 50% strength.

Depending on the system, this is a beam with a section of 150 * 150 mm or a board with dimensions of 50 * 150 mm. It is attached to the top row of masonry walls. If the house is wooden, its role is played by the upper crown. If the walls are made of light building blocks - foam concrete or aerated concrete and others - their rigidity is not enough to redistribute the load. In this case, a reinforced concrete belt is made over the last row of masonry, into which embedded fasteners are embedded - wire or studs. A bar or board is then mounted on them.

There are several ways to connect walls and Mauerlat:

• In the masonry (in the reinforced concrete belt) a smooth rolled wire of large diameter is fixed (two ends stick up). The board is then rendered in necessary places holes through which the wire is threaded. She then twists and bends.
• Studs with a diameter of at least 12 mm are immured in the wall. Under them, holes are made in the Mauerlat, a beam / board is placed) and tightened with nuts with wide washers.
• Having aligned the beam or board along the outer or inner edge of the wall, they take a drill with a diameter of 12 mm to make holes for the anchor bolts. They (the same diameter of 12 mm) are hammered to the very hat, then tightened with a key.

The distance between the studs (wire) should not be more than 120 cm. Cut-off waterproofing must be laid on the wall (belt) under the Mauerlat. It can be rolled roofing felt or waterproofing in two layers, it can be smeared with bituminous mastic.

Rafter installation

There are more than a dozen types of gable roof truss systems. First of all, you need to choose what yours will look like. Further, in order to make it easier to work, a template is made from thin boards for all cuts, cuts and other similar details. To do this, you may need to assemble the first form on the roof, and then make templates for the finished one.

The assembly order depends on the type of truss system. If the rafters are layered, they are installed gradually, assembling from the elements directly on the roof. In this case, it is convenient if the beams of the ceiling are laid and, if possible, the draft flooring of the attic or attic.

In systems with hanging rafters, a farm is assembled on the ground - a ready-made triangle of puffs and rafter legs with all the required struts, racks. The required number of farms is assembled at once. Then they are lifted to the roof, placed vertically there and attached to the Mauerlat.

On the one hand, this is convenient - it is easier to work on the ground, with a high assembly speed, the accuracy is high: one farm is not much different from the other, which simplifies the procedure. But it can be difficult to raise finished trusses, especially for large buildings. To make this easier, two inclined boards are installed, which at one end rest against the ground, and the other sticks out a little above the wall. Farms are brought closer to this “lift”, one by one they are installed below, ropes are tied and pulled along the boards to the roof. In the absence of a winch or crane, this is the most acceptable method.

The assembly of rafters requires certain knowledge: how and in what order to mount them, how to mark and make cuts. See the video for the assembly of one of the schemes with a headstock.

Assembly order of the truss system

Everything, the do-it-yourself gable roof is assembled and ready for installation of roofing material.

The process of installing the rafters itself raises enough questions, but there are many ways and it is impossible to tell about them all. See one of them in the video. The system is large and went up to the roof in parts, and there it was already going to single structure. For big houses it's comfortable.

Features of the installation of the truss system of a wooden house

difference wooden houses consists in the fact that the frame shrinks, and this leads to a change in the geometry of the truss system. If the elements are fixed rigidly, the roof may fall apart. Therefore, the mounts are made floating. There are special sliding mounts, with which in this case the rafters are attached to the upper crown and to the runs, if any (see photo).

In order for the rafter to move freely during shrinkage, its long part is fixed strictly parallel to its edge, and the support is placed strictly perpendicular. If necessary, a platform is cut out under it. Mark the mount so that the hook is in the lowest position or near it. They are mounted on special self-tapping screws that come with the kit (ordinary ones do not fit). If the installation is done on a log, so that the rafter leg does not slip along it, a semicircular hole is cut out in the lower part, on which it will rest.

Such fasteners are sold on any construction market, it is called "slippery". How to attach the slippery to the timber, see the video.

Video on assembling and installing a gable roof truss system

It is not easy to build a gable roof with your own hands: there are a lot of subtleties and nuances, there are different ways of fastening, building up. Describing them in words is a thankless task. This is the case when it is better to see. Below is a selection of videos that you might find useful.

Video report on how a gable roof is made

The story of the owner of the house about the stages of construction. There are interesting technical points that may be useful.

Two types of rafter connection: rigid and sliding

Video about the two most problematic types of connections.

How to determine the angle of the rafters

Full video report on the assembly of the truss system

This movie is just under an hour long, but the entire process is shown from start to finish with plenty of detail. The roof is placed on, but when installed on buildings of a different type (except for wooden houses), there is no difference.

The basis of a beautiful and reliable roof is a solid construction of the truss system. It is important to mount it so that it serves long years, especially in difficult places of contact with the walls of the building, chimneys and pipes 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, windshields 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 construction 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 possibility of arranging an additional living 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 minimum consumption building materials, such roofs are often used in budget suburban 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 support frame, on which ordinary 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

rafters 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

Hip roofs give the building a unique look, but differ increased consumption 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 at the junction internal corners or valleys. 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 daylight 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. Distance between pipe and wooden elements must correspond to a fire gap of 130–150 mm.

rafter system around chimney 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 roof beams with a counter-lattice and batten boards.

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 stronger truss system with more frequent trusses and pitch changes at butt sections with different type stingrays. 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 have an indirect effect on the choice of step. insulation material. For example, standard width the insulation is 60 cm, and the allowable pitch of 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 between the rafters tightly and without gaps.

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 hipped element. Even an ordinary multi-gable roof with gables on different levels is often 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 for under-roof ventilation is maintained on all slopes, otherwise condensate will damage the rafters, battens 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 given 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, a vertical post is connected with a tie-in to a horizontal run and a puff, then a 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 rafter system, which are used on various types 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 preparations to ensure efficient and fast assembly. Need to create safe conditions 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. For marking cuts, notches and corner connections building levels and goniometric tools are used, and when mass production templates are made of the same type parts. Washdowns on the rafters can be done in the following sequence.

1. The beam is exposed to the Mauerlat and ridge run, marked by level vertical lines and the exact position of the cut.
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 sprigs come to the joint at different angles in two planes, in this case, using the level, it is marked vertical angle joint and then desired angle the junction 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 fully justified, since even complex roofs it is quite possible to assemble with your own hands, having project documentation. In the absence of a project, you must make a drawing yourself future design with the main parameters and dimensions of the elements of the truss system.

Blanks for roof trusses can be collected 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. For threaded rods reinforced belt or the last crown of walls around the perimeter, solid mauerlat bars are mounted to ensure uniform 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 its role is usually played by the last crown of the wall

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. Attached to the rafters waterproofing film with a sag of no more than 20 mm and bars of a counter-lattice, 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 increasing skill and proper planning 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 roof 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 step by step instructions and strictly observe safety precautions, then success will be ensured.

The construction of a reliable truss system is one of the most difficult tasks in the construction of a roof. country house, cottage or garage. Nevertheless, do not rush to give up - today we will refute the popular belief that such work is beyond the power of a beginner. Knowing the rules for calculating, sawing and installing a roof frame, you can build a roof no worse than specialists. In turn, we will try not only to talk about the device, design and features of the construction of truss systems various types, but also share the secrets of experienced craftsmen.

Any, even the most seedy roof, is based on a strong power frame, called a truss system. The rigidity of the roof, and hence the ability to withstand even the strongest wind and snow loads, depends on how correctly this structure is mounted.
The truss system is the power frame of the roof, which perceives the entire wind and snow load.

The best material for the manufacture of rafters (trusses) is considered to be a bar or thick board made of softwood. And there is an explanation for this - pine or spruce lumber has a relatively low weight, and the presence of natural resins makes it quite durable. Even if the timber will have a small residual moisture, it will not lead when it dries, which is no less important factor than ease of use and long term services.

Depending on the size of the roof, the supporting structural elements can have a cross section from 50x100 mm to 200x200 mm or more. In addition, the length of the roof directly affects the number of rafters, because they are installed in small steps - from 60 cm to 1.2 m.

Structural elements of the truss system

The main requirement that is put forward to a wooden frame is the ability to resist bending and torsion. For this reason, a triangle shape is best suited for timber frame trusses. However, they can consist of several parts:

• rafter legs - the base of the roof frame, which has the greatest impact on the size and geometry of the slopes;
• crossbars (puffs) - boards that pull together a pair of rafter legs;
• runs - transversely installed bars, due to which the rafters are connected into a single structure;
• racks - vertical supports that serve to support the rafter legs or prevent deflection of the runs;
• struts - the same racks, only set at an angle to the vertical;
• beds - boards attached to the floor of the attic, on which supports are installed;
• mauerlat - a support beam installed on the bearing walls, to which the lower parts of the rafter legs are attached;
• filly - pieces of timber or boards that are nailed to the lower ends of the trusses and serve to equip roof overhangs.

Additional elements of the truss system make the roof frame more durable, rigid and stable

When choosing the design of the roof frame, it is important to find the very middle ground that will allow you to get a solid and reliable structure with minimal cost. For this reason, you can deviate a little from the established canons, if it does not concern the rigidity of the entire structure. For example, it is quite possible to do without fillies, and form a cornice overhang due to longer rafter legs. Or use not a solid Mauerlat, but pieces of timber laid only at the attachment points of the rafter legs - it all depends on the engineering ingenuity and experience of the roofer.

Rafter classification

Depending on the design of the roof and the purpose of the attic, the wooden frame may consist of several types of rafters:

Features and varieties of truss systems

To make an informed choice, you need to understand the features of various types of truss systems and know the strengths and weaknesses of each design.

Roof frame with hanging rafters

Since the principle of attaching hanging rafters does not imply additional support points, this design is used for buildings with a width of no more than 6 m. Installation of unsupported trusses involves attaching each pair of legs to opposite main walls, while their upper parts are fixed directly to the ridge run.

The roof frame with hanging rafters transfers only vertical forces to the walls, therefore it has simpler attachment points to load-bearing walls

During operation, a force acts on the hanging rafters, tending to push the structure apart. To compensate for the bursting force, a crossbar made of a wooden beam or a metal profile pipe is installed between the rafter legs. If the attic space will be used for household purposes, then the upper jumper is attached as close as possible to the ridge, and the lower edges of the pairs of rafter legs are connected with puffs. Such a scheme allows you to increase the useful height of the attic, without reducing the strength of the frame at all. By the way, if the lower jumpers are made of timber with a section of more than 100x100 mm, then they can also be used as load-bearing beams. It is necessary to ensure a reliable connection of puffs and rafter legs, since significant bursting forces also act on the place of their fastening.

Roof with rafters

Rafter rafters require the installation of at least one support, so they are used for buildings with internal load-bearing walls. The maximum length of a single span should not exceed 6.5 m, otherwise the strength and rigidity of the roof frame will suffer. To increase the width of the roof, the truss system is reinforced with intermediate supports. Even one additional rack allows you to increase the width of the roof up to 12 m, and two - more than 15 m. The rafter system is ideal when a large roof width is required.

The stability of slope trusses can be increased by using a sub-rafter frame with girders, posts and struts. In addition, this rafter system requires much less lumber costs. Versatility, strength and economy have long been appreciated as construction companies, and individual developers, most often using roof structures with layered beams in their projects.

Combined options

Today, the roofs of country houses amaze with the elegance of design, the quirkiness of shapes and the variety of configurations. There is only one way to build such complex structures - by combining both types of truss systems in one frame.
The combination of layered and hanging trusses allows you to get a truss system of any configuration

Even for the construction of not the most difficult broken roof both truss systems are used at once. The right-angled triangles located on the sides are layered truss structures. And they are connected due to the upper screed, which at the same time plays the role of a puff for the upper hanging rafters.

The procedure and rules for the installation of roof frames

Since two types of roof frames are used in the construction of roofs, we will consider the installation technology for each structure separately. However, before proceeding with construction work, it is necessary to study the methods of fastening structural elements to each other.

Roof construction with hanging rafters

It has already been mentioned above that hanging rafters are most often used in the construction of small or undemanding buildings. A log house in this case is an almost ideal option, since you can do without a Mauerlat. lower part rafter legs are attached to the upper crown or the edges of the ceiling beams (matrices) protruding beyond the perimeter of the walls. In the latter case, the puff must be moved up - this will allow you to put the beam on top of the finishing log and make the attic more comfortable.
To increase the height of the attic space, the puff should be installed as close as possible to the top of the roof

Preparatory work

The geometry of the slopes depends on how well the beams will be prepared for the rafter legs. A cord stretched between nails driven into the extreme beams will help to level the supporting surfaces..

1. It is necessary to cut down the slab, having received flat platforms for the installation of trusses. After that, you should definitely check how accurately they lie in the same plane. This can be done using a long straight rail and a level.
   Before installing the trusses, the supporting surfaces are aligned with the cord
2. After removing excess wood, in each beam you need to make a recess under the rafter spike. You can draw the places of future nests using the same nails and cord as in the previous case. Although the recesses for the rafters can be made both before and after the manufacture of the trusses, experts advise doing them first - this will allow you to try on with higher accuracy and convenience.
   The method of fastening the rafters depends on many factors - type support beams, their sections, features of the roof overhang, etc.
3. Professional roofers recommend installing an additional reference point in the center of the span of each tong - a vertical rail. One of its sides is used as an axis of symmetry, which will make it possible to monitor the strict observance of the geometry of the structure.
   In order to simplify the process of marking and mounting the roof frame, use vertical rails installed along the center line of the roof

Rafter manufacturing

In order for the rafters to have the same dimensions and configuration, they are made according to a pre-made template. For its manufacture, we suggest using the following instructions:

1. Take two slatted boards and bolt them together to form a drop-down compass design. The threaded connection should not be tightened strongly - the structure should rotate around the top. Be sure to check that the slats are 10-15 cm longer than the rafters - this will be needed to take into account the height of the thrust tooth.
   The simplest template allows you to get roof trusses of the same size and configuration
2. On the rail set as a guide, make two marks. The lower one should correspond to the height of the truss system, and the upper one should be separated from it by the height of the mounting ledge.
3. Install the template on the mat so that the corners of the boards rest against the recesses for the rafter teeth.
   In order for the structure to successfully cope with bursting loads, the thrust tooth at the end of the rafter leg is inserted into a recess on the floor beam
4. Align the axis of rotation of the "compass" with the upper mark on the rail and set aside the height of the spike from bottom corners conductor.
5. Lower the template down and cut the teeth along the drawn line. After that, raise the device to the roof and insert the spikes into the nests on the mother. Check the coincidence of the sample axis with the lower mark on the vertical rail. If necessary, move the bolt to the desired side and fix the angle between the boards with a cross member.
   Several methods are used to fasten trusses - it all depends on the type of support beams, the design of the roof frame and the section of its elements
6. Having adjusted the template in height, apply vertical abutment lines to each board. In conclusion, measure the length of the crossbar and build a template from the scraps of the boards for making overlays on the tops of the trusses.
   To attach the crossbar to the rafters, linings from pieces of an inch board are used.

After the template is lowered to the ground, it is disassembled and cuts are made according to the markings. In addition, they construct a separate pattern, along which the ends of the rafter legs will be cut. The manufacture and assembly of hanging rafters is most often done below, raising finished structures to the roof. If the weight and dimensions of the assembled trusses do not allow them to be pulled up manually, then the assembly is carried out on the spot. At the same time, the components of the truss system are fixed with nails ranging in size from 100 to 200 mm.

How to install roof rafters

In order to raise and install farms, you will need the help of at least one person. Fitting and setting the rafters on a plumb line alone is an extremely difficult task - you will have to fasten them to the struts more than once and repeatedly descend from the roof to control the deviation from the vertical plane.
With the help of a rafter tooth, it is possible to obtain such a reliable connection that only one nail can be used for the final fixation.

Raising the assembled rafters up, first mount the extreme structural elements, and then the central and intermediate ones. To strengthen the structure, a support is installed under each leg:

Having set the hanging rafters according to the level, they are fixed with temporary struts. After that, the lower ends of the beams are nailed to the mat or floor beams.
Various temporary structures greatly simplify the process of installing rafters by level.

It is not worth resorting to newfangled methods of fixing with the help of various corners and perforated plates. A reliable "old-fashioned" method of fastening with nails 200 mm long or building staples will be much better both in terms of strength and reliability, and in terms of cost. At this stage, do not worry about the design looking flimsy.. After the remaining elements of the truss system are installed and the crate is completed, the structure will acquire the necessary rigidity and stability.

Video: making and installing do-it-yourself hanging rafters

Features of the installation of layered rafters

The process of manufacturing and installing layered rafters is generally very similar to the construction of a hanging roof frame. The main difference is at the top point and it is due to the fact that the tops of the layered beams rest on the ridge run. In this case, the connection with the latter is performed in several ways:

• simple adjoining apart (in parallel to each other);
• with the implementation of a vertical joint (the same as when connecting the paired legs of a hanging truss);
• by tightly fitting the beams to the upper beam (using a vertical cut or notch).

If the design of the wooden frame provides for the support of trusses on the side girder, then the rafters are joined end-to-end, and recesses are made at the junction with the girder.
For fastening layered rafters, nails, building brackets or linings made of wood and metal are used.

To ensure the strength of the structure, the cuts should not be too deep.. Experts recommend making recesses no more than a quarter of the thickness of the beam or a third of the width of the board.

Individual developers most often resort to installing rafters in the following way:

• the upper part rests on the ridge beam by means of a vertical cut;
• from below, the rafter legs are held by a corner cut.

For marking it is convenient to use a construction square. After the scale is selected, on the sides of the right-angled triangle, the values ​​\u200b\u200bof the rise of the slope and half the span are set aside. Thanks to this, it will be possible to obtain the slope angle of the slope without resorting to mathematical calculations.

For the manufacture of rafters, we suggest using the most convenient method:

At first glance, this method is very tricky. However, even a cursory acquaintance with the given instruction is enough to master it perfectly. Of course, it is possible to set aside the necessary distances and make markings by calculation, however, when calculating angles and distances, it will be much easier to get confused.

It should be remembered that the cuts made in the rafter legs must be exactly the same, otherwise the roof slope will be uneven. To do this, you can use a wooden block as a template. It is only important that its thickness does not exceed 1/3 of the thickness of the workpiece.

For the most common slope angles, there are templates that professionals have already worked on calculating the configuration of. Using one of these patterns, you can significantly simplify the task of marking the corners of the cuts.
Templates with marked corners of the cuts allow you to simplify the process of manufacturing rafters

Assembly and installation of a layered structure

Video: installation of rafter legs of a layered roofing system

Methods for connecting rafter logs

When choosing a beam for overall roof trusses, you have to look for a reasonable compromise between the length and thickness of the rafters. The reason for this is the peculiarities of the standard range of lumber, in which longer beams have an increased section. On the other hand, their use is not always justified both technologically and due to an increase in the cost of the structure. The way out of this situation is to lengthen the rafter legs by splicing. The rigidity and mechanical strength timber, so the connection is performed strictly according to a certain method.

Oblique cutting method

The method of merging with an oblique cut consists in the fact that inclined cutouts (cuts) are formed on the mating parts of the bars. They should be carried out very carefully - after combining both parts of the timber, there should be no gaps, otherwise deformation will appear at the junction.
When splicing with an oblique cut, there should be no gaps and gaps between the mating surfaces, which can weaken the rafter and cause its deformation

When making cuts, a small transverse section is left with a height of at least 15% of the thickness of the rafter - the presence of the end part will make the connection more durable. To calculate the optimal length of the oblique cut, it is necessary to multiply the height of the beam at the place of the cut by two. The cut is fastened with nails, clamps or bolted connections.

Coupling

To lengthen the rafter by rallying (stitching), the edges of the boards are overlapped and a rack is installed in the center of the junction zone. The fastening of the elements is carried out with the help of nails, which are hammered in according to a certain scheme: Joining the boards by rallying allows you to do without additional overlays, however, it requires the installation of an additional support in the center of the junction area

In order for the beam to successfully cope with operational loads after docking, the length of the rallying section (T) is calculated by the formula T = 0.42 × L, where L is the length of the overlapped span.

frontal stop

The frontal extension connection is that the edges separate parts the rafters are carefully trimmed and butted together. For fastening, linings made of lumber with a thickness of at least 1/3 of the section of the main beam are used. The length of the overlays is determined by the formula L = 3 × h, where h is the width of the board.
When splicing with a frontal stop monolithic construction will only work if the fasteners are correctly placed

The fixation of all parts is carried out using a nail fight or bolted connections. In the first case, nails are hammered in two parallel rows, trying to place fasteners in a zigzag pattern. Threaded connection perform in a checkerboard pattern, determining the number of bolts depending on the length of the lining.

Compound length extension

To build up a rafter leg, it is not at all necessary to use both parts of the same section. With a compound build-up, a single element can be lengthened due to two boards that are sewn onto its side planes. The resulting gap is filled with l = 2 × h lumber cuts with a step L = 7 × h, where h, as before, is the thickness of the element being extended.
Composite extension of rafters allows you to attach crossbars, supports and other structural elements in the most convenient way

Tips from experts on the manufacture of rafters and assembly of the roof frame

When starting to independently design and install a truss system, be sure to consult with experienced roofers regarding the features of building roofs in your area. Perhaps their advice will keep you out of trouble and help you save time and money. In turn, we offer several recommendations that will help make the design more reliable and durable:

1. If a minimum cross-section bar is used to make a Mauerlat or top trim, then cuts can weaken it. For this reason, cutouts should only be made at the lower ends of the rafter legs.
2. In order to prevent precipitation from falling on the wooden frame and walls of the house, the roof must have an overhang. For its arrangement, pieces of timber (filly) are used, with which the length of the rafter legs is increased, or larger trusses are made.
3. Connection using cuts at an angle of 90 o cannot be used- in this case, the resistance of the element to load forces is significantly reduced.
4. If the elements of the truss system are connected by threaded fasteners, then wide washers or metal plates are installed under the heads of the bolts and nuts. Due to the increased area, the fasteners will not be pressed into the wood.
5. All wooden parts of the structure must be thoroughly impregnated with an antiseptic and fire retardant.
6. When determining the cross section of the puffs, they are guided by how close they will be to the ridge. The shorter connecting beam, the greater the load on it and the more powerful lumber and bolted fasteners are used.
7. When determining the cross section of a beam for the manufacture of rafters, do not forget to take into account the thickness of the heat-insulating layer.

Video: recommendations of experts on the correct connection of the elements of the roof frame

Modern materials and technologies allow you to build a roof of any configuration and purpose. Given this diversity, it is simply impossible to consider in detail all the options within the framework of one article. However, based on the basic principles of construction discussed here, you can easily cope with the very complex design. The main thing is to pay attention to the little things, to be attentive and accurate in work. And then the roof will be not only a reliable functional superstructure, but also a real decoration of your home.

Installation of rafters is the first and milestone roof construction. The overall success of the whole business depends on how the materials were selected, how the dimensions were maintained, whether processing and other work was carried out. There are general requirements for materials, the installation procedure and other nuances that will help to correctly place the frame of the future roof.

A bit about terminology

Do-it-yourself rafter system requires certain knowledge. All structural elements have their own names, which we will now get acquainted with.

So, what is a rafter? This Basic structure roofs with one, two or more slopes. It includes:

• rafter legs - inclined beams or boards that create the shape of the roof;
• racks - vertical bars or boards supporting the end and rafter legs;
• struts - inclined beams supporting the rafter legs.

Depending on the design, the rafters are inclined and hanging. The first type includes bars, which rest against the wall of the house with the lower part, against the roof ridge with the upper part, and have an intermediate support in the middle. This design is placed if the rafter leg has a length of more than 5 m. hanging rafters, respectively, do not have such supports.

Another component of the truss system is the run, which performs the function of strengthening the truss structures. This is a horizontally lying bar, perpendicular to the legs. There are ridge (in the place where the bars converge) and side.

In some designs, puffs are installed between the rafter legs. They create an additional connection and additionally strengthen the structure. If several vertical racks are placed, a horizontal beam is placed under them, which is called a bed. It takes on the load, evenly distributing it. All this is necessary to get the strengthening of the truss system. This will extend the life of the structure, while also providing better protection from wind and other natural hazards.

The service life of the bars will increase special impregnations from fire, fungi and pests. Having dealt with the basic terms, we will consider the sequence of actions necessary to install the truss system.

Laying the groundwork

To perform the work, you will need a number of tools, among which must be the following:

• level;
• roulette;
• hand saw;
• axe;
• chisel or chisel;
• pliers or pincers.

Do-it-yourself installation of rafters is usually done with nails, the length of which is selected depending on the thickness of the beams and beams. They are enough to provide high-quality fastening all structural elements.

We will begin to consider the sequence of actions from laying the foundation for the truss system. in stone or brick houses Mauerlat is used for this, and in wooden structures - the upper crown ( top harness). These are essentially runs encircling upper part walls. They are more massive than the beams that are used for the installation of the truss system.

Before laying the Mauerlat on a stone or brick wall you need to put a layer of insulating material. It will protect the wood from moisture that condenses on the surface of the stone. For these purposes, use the usual roofing material.

To ensure greater reliability of the roof structure, the rafter legs are cut into the Mauerlat or the upper crown. Such fastening of the beams will save the system from deformation, which may occur over time due to loads in the form strong wind or a thick layer of snow.

We put the rafters

How to install rafters? Depending on the angle of inclination of the roof slopes, they are divided into:

• pitched (angle of inclination more than 10 °);
• flat (angle of inclination less than 10°).

Depending on the size of the roof, the angle of inclination of the slope and the thickness of the bars in the system, a step is selected between the rafter legs. The minimum distance when attaching rafters to beams is 70 cm.

Experts note that the distance between trusses also depends on the type of roofing material that the owner of the house intends to use when building the house. For laying a soft roof is taken minimum distance. And for slate, metal tiles and other similar materials, the distance can be increased.

How to properly place the rafters so that the whole structure is even? To do this, first put one pair of legs on one end of the roof, and then the second on the other. A string is stretched between them, which acts as a guide. It will help to fix the rafters at the same level and evenly. It is important to ensure that the twine does not sag during work.

Fastening the rafters to the beams, as we noted above, is done with nails. Masters advise to make an end connection, and not an overlap. Between themselves, the components with which the installation of the truss system is carried out are also fastened with metal brackets. Self-tapping screws are used to fasten the rafters to the beams. This is considered a more reliable type of fastening.

It should be noted that part of the rafters extends beyond the edge of the wall for some distance. This creates a ledge that protects the wall from rain and snow. Standard scheme fastening the rafters to the beams provides for a minimum length of such a protrusion of 50 cm. The protruding part of the roof can be longer, depending on the needs of the owners of the future home.

The installation of pairs of rafter legs goes through the entire roof, from one edge to the other. The installation of the truss system must be carried out in such a way that it is possible to correct irregularities or structural errors in time.

Each pair of legs is attached in a supine position, after which it rises and is installed in the prepared grooves. After that, the rafters are fastened to the beams and pre-fixed. When several pairs are installed, they are fixed using runs.

building own house is always a waste: starting from the project and ending with its implementation, you cannot do anywhere without the help of professionals. But is it really so? Isn't it possible to do most of the work with your own hands? You can, if you use the tips from our site!

There is a lot on the resource, how about a reliable foundation for any building. But, in addition to a stable foundation, the coziness and comfort of staying in the house is affected by that which does not leak and helps to keep the heat in the room.

Any roof structure will not do without high-strength rafters, and their assembly is one of the most time-consuming tasks in the construction of a monolithic or private house. Frame for new roof you can buy at the nearest woodworking sawmill, and you can install it yourself, observing all the technological requirements and features of different configurations. Next, consider the main elements and methods for installing rafters on the roof of a private house.

Roof structure elements

Mauerlat- the main component of the entire system, a kind of foundation, which is installed along the perimeter of the walls and creates an optimal load balance, protecting the structure from involuntary movement at the moment strong winds or heavy rainfall. Mauerlat can be made from planed timber, in some houses it can be replaced by the upper wall trim.

rafter legs- designed to hold a kind of sandwich. A sheet of sealant is laid between the supporting rafters, and a crate is placed on top of it.

Runs- solid beams that are laid in level along the roof. Used to fix rafter legs. They are divided into several types: ridge run (located in the upper part of the roof), lateral (located in the center of the supporting legs of the rafters).

Racks- take on a small weight of the structure. They are used to strengthen the stops of the rafters and the ridge.

Struts- are installed specifically to hold the rafter legs. Mounted in an inclined position. Gives the building extra strength.

Installation of the truss system

To get started installation work for the construction of the roof of a private house, it is advisable to familiarize yourself with the theoretical part, from which you can learn how to properly install the rafters on brick or wooden walls. Consider the most common sequence for installing the elements of the truss system.

Mauerlat installation

Before laying the mauerlat on wooden walls, you can add one log at a time around the entire perimeter to increase the height of the ceiling. Under the upper logs, which will be the base, it is advisable to put a knitting wire, with which it will be attached to the base of the wall. An easier way is to secure the base with large anchor bolts.

First comes a waterproofing film or roofing material. Next, lay out the finished workpiece around the entire perimeter of the walls. In some cases, the length of the bars may be fewer walls in this case, they must be equalized.

How to connect mauerlat

After installation, we check the geometry. For this operation, a laser level is ideal.

This operation should not be neglected - the slightest inaccuracy of 1-2 cm threatens with poor-quality assembly of the entire truss system, which can lead to unplanned roof repairs as early as next year.

Good to know. by the most in a simple way check is considered a rope or fishing line. With their help, you can measure the distance of one diagonal (from one corner to the opposite), fix and compare with another, and if the result matches, then everything is done correctly.

We fix the corners of the Mauerlat.

We fix the entire structure with wire, anchor bolts or studs. For fastening with studs and anchors, holes must be made in advance. A low-speed electric drill can easily handle this. Screwing the bolts is best done in several stages, alternately on each side.

We make the correct installation of rafters

rafters

Before proceeding with the installation of rafters, it is advisable to decide on the type, there are only two of them - hanging installation roof rafters and sloping. Their main task is to fasten and hold all the elements, and the difference is the number of supports.

Inclined have 2 or 3 pcs. For small buildings with small spans, an inclined installation system is used shed rafters. Gable are used for domestic or public premises, which are endowed with additional, load-bearing partitions and columns.

In the area of ​​\u200b\u200bthe base of the beam, the rafter legs should fit snugly against the Mauerlat, and at the top - into the ridge run, which is mounted on racks mounted on the lower run. The connection is best made on pre-prepared cuts with metal clamps or staples.

Hanging lean on bearing walls in two places, additional props are not used.

Therefore, if the planned slope is less than 45 degrees, the horizontal pressure will be greater than the vertical one, which means that it is worth considering emergency reinforcement. Therefore, it is necessary to carry out all the calculations before starting work and decide how to install the rafters in your case.

Rafter system for the future attic

The most common method of fastening are ties made of metal or wooden structures. The place of their installation is selected individually and directly depends on the desired functionality of the attic space. For example, if the roof will be used in the role, the screed should be at the base of the rafter legs.

Installation of load-bearing rafters for a gable roof

To create a reliable fastening of the entire roof, which can withstand heavy loads, you must use the combined installation method, i.e. installation of rafters will take place using two technologies - inclined and hanging.

For installation, high-quality beams with antiseptic treatment. The most common size is 49.9 * 149 * 5000 mm. If the length of the beam is greater than specified, it is advisable to increase the height of the carrier beam to 180 mm. The installation of the rafter system should be carried out in a parallel manner, that is, having mounted the rafter on one side, we immediately set it on the opposite side.

Preliminary marking and drilling of holes for fastenings is best done on the ground.

In order for the supports to be as stable as possible, it is advisable to make the lower grooves according to the diameter of the Mauerlat.

Having selected the upper section of the intersection, we proceed in the same way and make a tie-in equal to half the diameter of the beam.

When fastening with an overlap, the top fastening should be obtained without additional protrusions.

In order for all the grooves to be of the same diameter, it is necessary to prepare a mortise template. The most common material for its manufacture is plywood or thick cardboard. According to a previously drawn up drawing, a layout is cut out of plywood in two copies, nailed to a beam on both sides and outlined with a pencil. The tie-in made according to this principle will turn out to be dense and as even as possible.

It is desirable to make cuts as simple as possible, since intricately cut joints can be absolutely unreliable.

As far as possible, the mounted planes should be perpendicular to the load forces that may appear along the wooden elements.

After creating the structure, it should be securely fixed to the Mauerlat. For this, ordinary nails or special anchors are suitable. The next step is to determine the minimum distance of the rafters from each other.

To determine it, look at the table.

Rafter leg length, m	Distance between adjacent rafters, cm
	110		140		175		213
	Rafter leg thickness, cm
	bars	logs	bars	logs	bars	logs	bars	logs
Less than 3	8 * 10	Ø 10	8 * 13	Ø 13	9 *10	Ø 10	9 * 16	Ø 16
3 to 3.5	8 * 13	Ø 13	8 * 16	Ø 16	8 *18	Ø 18	9 *18	Ø 18
3.6 to 4.2	8 * 16	Ø 16	8 * 18	Ø 18	9 *18	Ø 18	10 *20	Ø 18
4.2 to 4.9	8 * 18	Ø 18	8 * 20	Ø 20	10 *20	Ø 20	–	Ø –
4.9 to 5.7	8 * 20	Ø 20	10 * 20	Ø 20	–	Ø –	–	Ø –
5.7 to 6.2	10 * 20	Ø 20	12 *22	Ø 22	–	Ø –	–	Ø –

Trying on rafter legs

Below we consider the main aspects that will affect the choice of the section of the rafter leg:

• We find out what will be the constant pressure on the bars.
• Covering material used in a particular case.
• The desired angle of inclination of a single-pitch or gable roof, which is easy to calculate if you use the tips from.
• Dimensions of the house and the estimated complexity of installation.
• Climatic conditions in your area. The calculation is the level of precipitation in summer and winter.
• The material and quality of the rafters themselves. The best option would be bars obtained from coniferous trees. But sometimes you can stumble upon a fake, so it is better to select higher quality varieties so that the wood can be used to determine the natural origin of the material.

The main characteristic of the wood used is its moisture content. A suitable level should be within 22 percent. If you wondered how to install rafters with high humidity? The answer is no! They need to dry well. The whole reason is that excessive moisture will evaporate over time, and the wood will shrink, which will lead to its deformation and change in size, and this can lead to more negative consequences, for example, a violation of tightness.

Let's move on to the legs. There are several reliable fasteners in use today. They can be used on all types of roofs. The reliability and correctness of attaching the rafters to the Mauerlat will depend on their execution:

• sliding;
• Rigid.

For both cases, you can use a varied combination of hanging and inclined rafters.

hard way it is used for standard structures that are installed without turns, bends. To use it, it is advisable to put risks on the bars in advance and make the appropriate cuts, followed by attaching the rafter leg to the Mauerlat.

sliding(very often called free mount) has several stages of fastening. This is done in order to leave a certain margin for the subsidence of the frame; it can be used in conjunction with poorly dried rafters.

It is difficult to overestimate the importance of the correct installation of rafters for the stability and durability of the roof.

Thus, by applying the basic knowledge gained from this article, you can not only control the process led by professionals, but also do most of the work yourself, while significantly reducing costs and saving time and nerves.

Good luck with your construction!