Make your own roof truss system. How to make a gable roof truss system with your own hands. Features and varieties of truss systems

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 structural parts 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 rafter legs 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 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 rafter 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 sprigs, and trusses resting on the corner lintels serve as 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 building 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 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 all slopes maintain a gap for under-roof ventilation, 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 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.

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.
The angle of inclination is fixed on the bevel, and the dimensions of the insert are measured with a tape measure or square.
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.
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 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.

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
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.
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
The second blank is installed in place of another pediment.
Both farms are fixed in a vertical position, which is controlled by a level or plumb line.
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
Intermediate truss structures are installed with the selected step. All of them should be aligned vertically and along the stretched cords.
Ridge and additional horizontal runs are mounted (if they are provided for by the design).
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
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.
With the help of gable and frontal boards, overhangs are formed that protect the walls of the building from precipitation.
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.

When building a small house, garage or outbuilding, it is not necessary to hire professional builders. Most of the work can be done on your own. Even if we are talking about such a complex structure as a truss system. Even some of the materials, or rather the elements, can be made by hand. For example, rafters. This element is the main one in the roof structure. And how can you make rafters with your own hands? What are the nuances and how to avoid mistakes? This will be discussed below.

What material to choose

Making rafters for a house with your own hands is a completely doable task. But before you start it, you need to choose the right material. It is from this that the whole course of further work will envy.

And what options for the material for the rafters are used? The following can be used for this:

Reinforced concrete products. This option is used in the construction of large industrial facilities. It is impossible to make such rafters on your own. And their use in the construction of private houses is not practiced.
Iron. It is quite possible to make metal rafters with your own hands. But they have many disadvantages. First, the metal is afraid of corrosion. Secondly, such rafters will weigh a lot. And this makes it difficult to do the installation yourself without the involvement of technology.
Wood. It is this material that is most often used in the construction of the truss system of a private house. Wood is easy to process. Therefore, making rafters with your own hands will be quite easy.

It is wood that is used for construction. But this material also has several options. Wood can be found in the form of logs, beams and boards. And what is better to use for rafters? Much will depend on the design itself. More specifically, on the size and required strength.

Logs, due to their heaviness and bulkiness, are rarely used for rafters. Exceptions can only be a pitched roof. And then in this case, thin logs from young trees are used for rafters.

Bars and boards are a completely different matter. It is they who are used in order to make rafters for the roof. Bars are used in cases where the structure is large in size. At the same time, the loads from precipitation and the weight of the roofing material are quite large. Boards are used for rafters in cases where the roof is small in size. However, they can be used singly or in pairs.

Choice of wood

Making rafters is a responsible business. The strength of the entire roof structure will depend on it, so you need to pay attention to all the little things. Before proceeding with the manufacture of rafters, you should stock up on material. As mentioned above, wood is best suited for this.

And what breed is better to choose? What kind of wood can be used to make strong and durable rafters? You can use the following to work:

Pine. It is this option that is most often used in the construction of a roof truss system. Pine has many benefits. Firstly, such wood is impregnated with resin. This allows you to protect it from external influences. Secondly, the material is soft, and it will be easier to make rafters out of it with your own hands. Another plus is that pine is inexpensive wood. And this means that you can save;
Spruce is another common material for making roof rafters. This wood is strong, light and easy to work with. But spruce has a small drawback. It is more susceptible to external influences than pine;
To make rafters, you can use oak. The material is durable and well processed. But oak is very expensive. It is best used for .

Rafters can also be made from other materials. For example, you can use beech. This wood is strong and durable, but it is expensive and difficult to process. If you have chosen aspen, then you should be aware of some of its shortcomings. Most importantly, this wood often rots from the inside.

The best option, according to most professionals, is pine. The wood is quite common, it will be easy to buy. But the most important thing is its durability and ease of processing. You can easily make rafters and other elements of the roof structure from pine.

There is another modern version. For the manufacture of rafters, you can use glued beams. This material has several advantages. First, it is not deformable. Secondly, it has standard dimensions, which greatly facilitates the fitting of rafters. But glued beams are rarely used. This material is new, and it is not cheap.

It is very important to consider the quality of the purchased wood. Of course, everyone knows that it is not worth buying bars or boards with traces of decay. But, besides this, you should pay attention to the moisture content of the wood. This parameter should not exceed 10-15 percent. Otherwise, the rafters will warp, and the roof will soon require repair.

What sizes to choose

If wood is selected, then before buying, you should deal with a few more parameters. To make the rafters correctly, you need to decide on their cross section and length. Both parameters are determined by calculations.

Having learned what load the rafters must withstand, you can calculate their cross section. There are many tables on the Internet. They indicate the bearing capabilities of the rafters, depending on the material used in the manufacture, length and section. With their help, you can easily select the desired parameter. The only thing that still needs to be taken into account in the calculations is this. The closer they are to each other, the smaller the cross section can be used.

How to make rafters on the roof? In principle, there is nothing complicated here. Having learned what the length should be, the timber or boards of the desired section are sawn off according to the desired markings. Next, a cut is made for and in the area of \u200b\u200bthe ridge, and if another connection method is used, then this is not necessary. But to do everything right, you should take some advice from experts. Namely:

The roof is a complex and important architectural element of any building. Its construction should be treated with special attention, it must be remembered that the installation of a truss system requires considerable experience in performing such work and a special tool. You should not take on the creation of a roof for those who hold a carpentry and measuring tool in their hands for the first time - the results of the activity can be very negative.

There are two types of roofs depending on the number and placement of rafter support points, but each developer can, at his own discretion, slightly change the specific design of the truss system. This takes into account the operating conditions of the building, the purpose of the attic, the climatic zone of location, the technical parameters of lumber and roofing. Of course, the type of truss system is influenced by the personal experience and preferences of developers.

Before proceeding with the manufacture of rafters, you should decide on their type, method of attachment and linear dimensions. Only in this case, you can be sure of the strength and safety of the structure.

How do various factors affect the parameters of the rafters?

physical factor	Brief description of the influence on the parameters of the rafters
	Rafters must withstand snow and wind loads. During the calculations, it is necessary to take the actual maximum values of snow cover from the tables of building codes and rules, take into account the strength and rose of the winds. The data allows you to find out the total load on the roof slope, depending on its area and angle of inclination. Further, it is already possible to determine the dimensions of the rafters, their number and step. In this case, a safety factor is necessarily laid down. The fact is that lumber does not have stable and identical strength values, too many unforeseen factors affect these indicators. For most cases, 50 × 150 mm or 50 × 200 mm boards are used for the manufacture of rafter legs.
	Gable roofs can be layered and hanging. For hanging roofs, you need to make rafters from more durable boards. This takes into account the method of fixing the elements to the Mauerlat. If a cut is made, then the width of the boards should increase by the size of the cut. The fact is that the cut in this place automatically reduces the width of the material that receives the load. If a cross cut 60 mm long is made on a board with a thickness of 200 mm, then only the remaining width of 140 mm is taken into account. Accordingly, if rafters from 200 mm boards are selected when calculating loads, but unforeseen cuts of 60 mm are made during fastening, then the width of the blanks for rafters increases to 260 mm. This remark is made for those who like to abuse various notches and cuts for the thrust areas of the ends of the rafters. Currently, there are many special devices that allow you to firmly fix the rafter in the desired position without sawing.
	For residential buildings, rafters must have a safety margin of at least 1.4 of the calculated values. For non-residential structures, the coefficient is reduced to 1.2. Conclusion - the dimensions of the rafters on the houses are larger than on garages and other outbuildings.
	Residential attics (mansards) must have an insulated roof. The width of the rafters must correspond to the thickness of the insulation layer. At the same time, it is necessary to adjust the step between the rafter legs, depending on the standard width of the insulation. If in this climatic zone the optimal thickness of the roof insulation is 200 mm, then it is recommended to choose the same width for rafters. Various extensions of narrow rafter legs during roof insulation are not considered the right solution.

This knowledge will help you make the right decisions both during the manufacture of rafters and during their fixation directly in place. Mistakes in the construction of the truss system are too expensive, you should not show excessive self-confidence.

What influences the choicesizes andwaysmountsrafter

A very important point. The task of any fixation is to ensure the stability of the connection node, while it can be fixed or have one or more degrees of freedom. This cannot be achieved without knowledge of the loads affecting the rafter legs. Loads can be permanent and temporary, dynamic and static, unidirectional and multidirectional.

Constant vertical forces. Arise due to the impact of roofing and roof insulation materials. Due to the fact that the rafter legs are located at an angle to the vertical force, they are subject to bending and bursting loads. The magnitude of the forces is determined after the construction of the diagram, on the basis of specific bending and bursting forces, the thickness and width of the boards for the rafters are selected. Fasteners must prevent the spreading of the truss system.
Variable vertical forces. Appear in winter, the value depends on the height of the snow cover.
Lifting wind forces. As a result of gusts of wind, lifting forces act on the roof. They do not affect the dimensions of the rafter legs, efforts are taken into account only when choosing the type of fixation, it must provide for and hold such loads.
Lateral efforts. The value depends on the windage of the roof. As a result of gusts of wind, lateral forces act on the truss system. They increase bending and tearing loads. This feature must also be taken into account during the manufacture and installation of rafter legs.

There are options for rigid fastenings of truss trusses; for this, metal plates, corners, self-tapping screws and nails are used.

Sometimes it is required to use floating rafter connections to compensate for changes in the size of wooden houses. For floating connections, special fasteners and bolts are used. The second allows the rafter legs at the top to turn a little.

Another example of a free rafter connection is a sliding one. It is used on wooden log cabins and makes it possible to compensate for the natural shrinkage of the house.

What elements are used to increase the stability and bearing capacity of the rafters

As a result of the correct choice of the truss system and methods of fixing its elements, the structure must be stable, compensate for natural fluctuations in linear parameters and withstand various loads that occur during operation. To fulfill the conditions during the fixation of the rafters, additional fixation elements can be used.

Runs

Most often they are mounted in the ridge part of the system, the upper ends of the rafter legs rest on them. To increase stability, cuts may be provided. The top connection is rigid or floating on bolts. On large roofs, girders can be installed in the middle of the rafter legs or in other places with critical loads.

vertikAflax racks

They are installed to strengthen the rafters; due to the use of racks, elements can be made from thinner lumber. Vertical racks with their upper end abut against the rafters, and with their lower end against the bed or ceiling beams.

cornerOpores

Retain bending and expansion forces, universal use. Corner stops can be placed in any places of the rafter leg that cause concerns about strength. Due to such stops, the resistance of the rafters to bending and tearing forces is significantly increased.

Puffs(crossbars)

Purpose - to keep the rafter legs from sprawling, they are used on hanging rafter systems. Most often they are placed in the upper part of the truss; boards with a thickness of about 20–25 mm can be used for manufacturing. The fact is that they work in tension, lumber holds such efforts well. Boards do not work well in compression, quickly bend and lose their original strength indicators.

Knuckleadki

They are used in the upper ridge part of the rafters, due to the use of puffs, the strength of the knot connection increases. Puffs can be made of wood, plywood, OSB or metal.

Bosses(stops)

They have many specific names. They are ordinary pieces of boards 30–40 cm long and 40–50 mm thick, fixed at the bottom of the rafters. They rest against the Mauerlat and do not allow the structure to slip. The use of bosses allows you to perform a rigid connection of elements without sawing the rafters. We talked about the problems that arise in connection with sawing in this article above.

Prices for various types of timber

Options for connecting the ridge knot of the rafter legs

The horse is one of the main and most loaded elements of the truss system. The node has several connection options, you should choose a specific one depending on the general parameters of the roof.

With a large length of slopes, it is better not to use a ridge beam, but instead to put two parallel runs and puff crossbars. This design is easier to do, it is more stable and safe.

For a hanging roof, you should choose the most reliable ways to connect the rafter legs, these systems have a minimum number of additional stops.

Prices for various types of fasteners for rafters

Fasteners for rafters

step by stepWithTruction of the mouthAnew rafters

For rafter legs, coniferous boards 50 × 200 mm, first-class lumber, are used. The boards must not have traces of rot or fungus, significant malformations and deep cracks. It is strictly forbidden to use low-quality lumber for the manufacture of the truss system.

To increase the protection of roof elements from decay, it is recommended to use fire protection.

Rafter blanks should be impregnated at least twice, while the material must be dry and clean. Processing is done on a flat area in dry and clear weather.

It can be impregnated with a roller, brush or air gun. It is not recommended to use household hand sprayers - too long and hard. Boards can be lifted up after complete drying of the impregnation.

Our gable roof has a ridge run, vertical supports rest against a bed located on a load-bearing wall in the middle of the building.

Practical advice. If the house is quite high and the boards are heavy, then it is recommended to make an elementary device to protect window openings from damage. To do this, two boards are knocked down in the form of a square, the length and width are selected taking into account the parameters of the opening. The device is installed on the windowsill, and the rafter boards do not damage the foam blocks during lifting.

Prices for fire-retardant impregnations

Preparatory operations

The manufacture of rafters begins with preparatory operations.

Step 1. Raise the rafter boards into the attic. For convenience, place them evenly along the length of the building, put one end on the Mauerlat, and the other on the run bed. First you need to install the extreme rafters on both sides of the roof of the house, pull a thread between them and install and align all the remaining ones along it.

Step 2 Check again the position of the ridge run. It should be located exactly in the middle of the roof. Its displacement by 1–2 centimeters will not affect the strength of the roof as a whole, but it will somewhat complicate the manufacture of rafters and the laying of roofing materials. In addition, an experienced builder may notice a mismatch in the size of the slopes and, accordingly, the asymmetry of the roof. It is recommended to achieve a situation so that the ridge run is located along the line of symmetry, if this is not associated with great difficulties. The final decision is made by the foreman on site and depends on the magnitude of the offset and the amount of work to correct the error.

How to straighten a run?

Attach a batten board to the Mauerlat, it is lighter, easier to lift and fix. The second end should lie on the run. The board is nailed to the Mauerlat with an ordinary smooth nail or screwed with a self-tapping screw.
Climb to the top of the run and use a tape measure to check the distance from the edge of the run to the Mauerlats installed on opposite walls. Work very carefully, it is advisable to use insurance. Unfortunately, in practice, few people follow the safety rules, but in vain. Falls from height can cause very serious injury.
Align the purlin to the center and secure the board. To increase rigidity, fix the same board on the other side of the run.

Now everything is ready, you can proceed to the manufacture and installation of rafters.

Installationrafter legs

If you work alone, then you need to fasten a piece of rail to the run at the place where the first rafter is fixed. A rafter board will be temporarily fixed to it to prevent it from slipping down.

And at this time, you can perform work on the manufacture and preparation for connecting the upper part of the rafters.

Step 1. Lift and install the rafter board in place, clamp it to the previously fixed rail with a clamp.

Step 2 Draw lines to cut out the thrust pad. This is done in two stages. First, draw a horizontal line. To do this, press the rail, square or other even object firmly against the horizontal surface of the run.

Second, draw a vertical line. Now the ruler or square should be pressed against the side surface of the run.

Important. The width of the ruler should be no more than 2-3 cm, it is not necessary to make deep cuts and significantly reduce the width of the rafter leg, it loses its maximum design strength.

Make the same markup at the bottom of the rafter. Only now the ruler needs to be pressed against the Mauerlat surfaces.

Step 3 Remove the board and carefully cut out the seats. You can work with a hacksaw or an electric circular hand saw.

Practical advice. If the cuts are made with an electric circular saw, then it is better to cut in two steps. First cut to the mark, then turn the board over and cut again to the mark. Knock out the cut piece with a hammer, and remove the remaining protrusion with a chisel or chisel. No need to go behind the line with a saw and try to cut off the ledge in one go. This method increases the cut by 3–5 cm, depending on the diameter of the disk, which significantly reduces the bearing performance of the rafter.

Step 4 Install the prepared rafter in place and check the correctness of its manufacture. Do the same operations with the second leg of the farm.

Step 5 Place the rafters with an emphasis on the Mauerlat and the run, pull them together with a clamp in the upper part. Find the middle of the run and transfer the line to the rafters, use a level or building square (only if the plane of the run is strictly horizontal).

Step 6 Saw through two rafters at the same time along a vertical line. The boards must be tightly clamped with a clamp. Pay maximum attention, the saw blade should be perpendicular to the plane of the rafters. If you cut it obliquely, then the ridge joint will not fit tightly, and this reduces the stability of the truss system and is considered an obvious construction defect.

With a lack of practical experience in performing such work, the first leg may have a gap in the ridge part, if it is within 1–2 mm, then there is nothing to worry about. If it is more than 4 millimeters, then you need to correct the element. See which planes of the thrust pads do not allow the upper cut to fit tightly. Approximately indicate the amount of additional cut. Remove the rafter and remove the interfering protrusions. Check the connection again, if there are gaps, repeat the operation. As practice shows, experience appears on the second or third rafter and no further corrections need to be made.

Step 8 Secure the rafter legs firmly in place. For this, it is recommended to use metal plates and corners, it is simple and easy to work with them, the strength fully meets the requirements for the truss system.

For each pair of rafters, you will need one large reshaped plate to connect the ridge knot, two 50x50mm corners for fixing to the run and two 60x80mm corners for screwing to the Mauerlat. The thickness of the metal is at least two millimeters.

In the same way, install the extreme rafters on the other side of the house, pull the threads between them. One at the top and bottom and one in the middle. So that they do not interfere during the manufacture of rafters, make a gap between the thread and the plane of about one centimeter.

Real professionals never make one rafter in the attic of a house. Such an algorithm of work significantly increases the construction time, complicates the process itself and makes it unsafe. It is very dangerous to work with electric tools on unsuitable sites, injuries from them are severe, often causing disability.

If the house is delivered with high quality with exact observance of dimensions and rules, then the rafter legs are made according to one template on the ground. Finished elements are assembled on the roof. This technology increases labor productivity by 3-5 times, at the same time the quality of the rafter system is improved, it is more reliable and durable. Of course, the wages of builders also increase proportionally. They work from the development and receive money not for the time spent in the attic, but for the assembled roof.

Prices for popular models of screwdrivers

Screwdrivers

Video - Manufacturing and installation of rafters on a gable roof

The construction of the roof frame is carried out according to the developed project, which indicates all the necessary parameters, including the type of construction, the pitch of the rafters, the section of the elements and the method of mounting the nodes.

System calculation principles

During the operation of the roof, its frame experiences high loads of various types.:

constants (the weight of the rafter system itself and the roofing pie);
periodic (wind and snow load, the weight of a person servicing or repairing a roof or chimney).

In order to correctly calculate and make a reliable roof, it is necessary to determine its configuration, choose the type of roofing, and calculate the optimal angle of inclination of the slopes. The degree of complexity of the frame and the dimensions of its elements to a certain extent depend on the parameters of the design load, the main part of which falls on the rafters. It is advisable to choose such dimensions of a wooden rafter as a section with a certain margin of safety.

How to determine the length of the rafters? For calculations, it is required to apply the Pythagorean theorem (if the length of the end wall and the height of the ridge are known), or the sine theorem (if, in addition to the length of the end wall, the angle of inclination of the roof slope is known).

For the manufacture of rafters, you can use boards or timber. To build a roof frame, designed for high loads, will help additional elements that give the structure rigidity.

Determine the pitch of the rafters

To calculate the pitch of the rafters, it is necessary to take into account the weight of the roofing, the angle of inclination of the slopes, wind and snow loads. On average, the step (the distance between adjacent legs forming the roof slope) ranges from 70 to 120 cm.

To eliminate the risk of deformation of the rafter legs under high loads, it is recommended to use dry lumber when installing the rafter system. Usually it is a beam or a board with a thickness of at least 50 mm. The exact dimensions of the wooden rafters and other elements are determined based on the requirements for structural strength.

The pitch of the rafters depends on the degree of slope of the roof and the length of the rafter legs. To build a solid roof by covering a large span between the ridge and the top of the wall, the pitch of the rafters should be reduced. For example, for a roof with a slope of 45 °, the maximum step should be no more than 80 cm. The rafter step should also be reduced when using heavy roofing materials, which include ceramic tiles, cement-sand tiles, asbestos-cement slate.

Calculation of the section of the elements of the truss system

If you have to build a roof with your own hands, you must complete. Also, you should pay attention to the characteristics of the material from which the rafter legs are made.

Regulatory documents regulate the bearing capacity, which wood of various species has. If the cross-section of rafters from timber or boards, weakened by cuttings and / or holes for bolted connections, is considered, the load-bearing capacity of wood is calculated with a factor of 0.8 of the standard value. It is also necessary to pay attention to the type of wood for manufacturing - defects reduce its resistance to stress. The cross section of the rafters is selected taking into account the standard dimensions of the lumber. To make a continuous supporting structure should be made of timber or boards with a length of not more than 6.5 m.

Having calculated the system and determined the dimensions of the rafter legs and crossbars, it is required to calculate the total weight of these elements and add the resulting value to the calculated loads:

the total volume of lumber required for the roof frame is multiplied by the volumetric weight of the wood;
the resulting value (own weight of the rafters, kg / m2) is added to the calculated load;
the calculation scheme of the structure is recalculated using the result obtained above.

Treatment of truss elements with an antiseptic

In private construction, the construction of a truss system is most often carried out from lumber, since wood is affordable and allows you to make structures with your own hands without the use of complex tools. Wood material prepared for installation (such as timber, logs) often gets to the construction site already treated with protective agents in a production environment. But a board or a bar that is not impregnated with special compounds is usually used for manufacturing.

How to process the rafters before installing the roof frame? Treatment is required to protect the wood from rotting and prevent fire hazards. Treatment with antiseptic and flame retardant can be carried out separately. With the use of a complex fire and bioprotective agent, processing will take half the time.

Treatment with an antiseptic or a combined composition should be performed in two steps. It is necessary to impregnate the top layer of wood with a special liquid, applying it with a brush or roller. After the first layer has dried, the antiseptic treatment is repeated.

pitched roof rafters

How to make rafters for a pitched roof? Do-it-yourself construction of a truss system of a shed or gable roof requires a careful approach to the manufacture of rafter legs. Dimensions are calculated at the design stage of the roof. To properly make these structural elements, it is necessary to use lumber of a section and length regulated by the project.

The degree of complexity of the work largely depends on which design is chosen for installation. If it is required to make layered rafters from boards or timber, each element is adjusted at the installation site when attaching it to the ridge run and Mauerlat. It is important to strictly monitor the observance of the geometry of the entire structure.

Hanging roof trusses are more convenient to make according to a template in order to achieve an exact match in the dimensions of each structure. For this, cutting in boards and assembling trusses is recommended to be done on the ground. Then it is necessary to check the horizontalness of the mauerlat or support beams, the geometric dimensions of the building box. Having eliminated possible shortcomings, you can proceed with the installation of roof trusses on the house.

Diagonal rafters

Do-it-yourself arrangement of the hip roof truss system requires the installation of various types of rafters, such as:

sloping (diagonal beams forming a triangular slope);
central hip;
side;
shortened (spidermen).

The side rafter legs are made of a board and installed in the same way as elements of a conventional pitched roof with a hanging or layered structure. The central hip rafters are layered elements. To make sprigs, bars or boards are used that are attached to diagonal beams and Mauerlat.

How to make rafters for a hip roof? In order to properly mount this type of roofing structure, it is required to accurately calculate the cross section and angle of inclination of the sloping beams. The dimensions of the elements depend on the length of the overlapped span. It is important to observe symmetry when installing diagonal rafters, otherwise the roof may deform under load.

Making rafters to a given size

The use of unified lumber for the manufacture of various elements of the truss system allows you to optimize construction costs and simplify the calculation and installation of roof units. In particular, if it is necessary to make rafter legs of a certain section and length, a solid beam, its segments or boards can be used.

To make a rigid beam with your own hands, the method of rallying boards is used - they are connected by wide sides and pierced in a checkerboard pattern with nails. A long beam of a given section can be made from four or more properly cohesive boards - interconnected with a shift of half the length of the board. Such a beam is highly durable and can be used as a diagonal rafter.

When deciding how to lengthen the rafters, you can apply the liner method. In this case, a third board is placed between the two boards, protruding to a certain length. To connect the boards, nails driven in a checkerboard pattern are used. It is important not only to carefully align the boards, but also to put fragments of the board (inserts) corresponding in thickness to the central board into the empty gap between the extreme elements. This method allows you to increase the length of standard rafter legs (not hip).

Principles of fastening rafters

To ensure the reliability of a do-it-yourself rafter system, it is necessary to decide in advance how to fix the rafters in the ridge and to the roof support. If it is planned to make a fastener that will prevent the deformation of the roof during the shrinkage of the building, it is necessary to fasten the rafters together at the top with a bolt with a nut or a hinge plate, and install a special fastener at the bottom - a sliding support.

The truss frame sets the geometric and operational parameters of the pitched roof. Due to violations in the installation technology, due to flaws in the manufacture of its elements, distortions of the system, traditional leaks, holes in the coating appear, threatening emergency situations.

In order to build a reliable and stable roof structure, you need to clearly know how the sawing and installation of rafters is performed, followed by fixation to the supporting elements.

Rafters, or rafter legs, are wooden or metal beams installed on the house box at a given angle. They determine the configuration of the roof structure, take on and steadfastly resist the sum of permanent and temporary loads acting on the upper enclosing system of the building.

The structural simplicity of the rafter legs is extremely deceptive. In fact, these are quite complex elements that require careful marking and accurate cutting. Inconsistencies in the connections of the rafter legs with the Mauerlat, with each other and other components of the system lead to a change in the shape of the slopes, a violation of the integrity of the coating and the destruction of nodes.

On the other hand, the competent installation of rafter legs can correct some errors in the construction of the house box, and not aggravate the situation by clearly repeating and increasing the wall height differences. True, in such situations, the frame elements are made individually and scrupulously adjusted in fact directly at the facility.

However, before dealing with the specifics of installation, you need to find out what their design differences are, according to which the rafter legs are divided into two groups, these are:

Hanging. Type of rafters that do not have an upper support. At the top of the roof, the rafter legs rest against each other with their ends. So that under the weight of the components of the roofing cake and snow, such a design does not burst the Mauerlat beam, the hanging rafters are connected with a horizontally installed puff.
Layered. A kind of rafter legs, stacked on two supports of different heights. At the top, they most often rely on a ridge run installed in the cross to the rafters, less often they rest against each other, cut down at an angle. The bottom rests on the Mauerlat beam or rests against it.

The scope of their application and installation technology depend on which group the rafter legs belong to. The hanging variety is collected on the ground, and the trusses, made in the form of peculiar triangles, are raised to the roof and mounted in a form completely prepared for installation.

The advantage of building a truss frame using hanging technology lies in the safety of work and the ability to perform nodal connections as accurately as possible. If the simplest version of a hanging truss with a puff at the bottom is used in the construction of the roof, you can abandon the Mauerlat device, in place of which a narrow leveling board is quite suitable.

The disadvantages of hanging technology are accompanied by advantages. For example, a truss assembled on the ground is much more difficult to transport to the installation site than boards and timber for layered rafters. There are restrictions on the spans to be covered: the limit is 14 m, above which it is unreasonable to install wooden beams prone to sagging without intermediate supports.

The rafter legs of the layered group both top and bottom are based on independent structures. The top of them is laid on a purlin structure, which is mounted on the floor beams or on the bed, replacing the Mauerlat on the inner wall. The bottom is either installed on the Mauerlat, or rests against it, catching on the bar with a tooth or a support bar sewn instead of a tooth.

The advantage of layered systems is rightfully recognized as the possibility of overlapping almost any span in size. It’s just that with an increase in the overlapped space, the design becomes more complicated: it is supplemented with struts for a couple with racks, additional runs, coupled with beds, fights.

The layered structure is assembled and mounted longer, because. it is built not from farms, but from individual elements. However, just this scheme has more opportunities to correct the shortcomings of a box or an unevenly settled log house. Because layered rafters are stacked individually, it is possible to slightly change the position and size of the node, in order to eventually form a perfectly aligned slope plane.

The specifics of the manufacture and installation of rafters

It is clear that for the construction of the truss system, lumber will be needed - long-length products of timber processing enterprises with clear geometric parameters. You will need a board or timber, on which, of course, there are no mounting cuts and cuts for installation.

Why are cuts and cuts needed? The fact is that when placed on an edge, boards and beams have too little support area. They are in contact with the Mauerlat with only one vestma in a thin line, because of which, at the slightest load from above, they can tritely “move out” from their position and drag the entire structure with them.

In order to increase the area of \u200b\u200bsupport in the junction of the rafter and the Mauerlat, or it and the additional run, a corner cut is selected in the beam or board, a tooth is cut out or a support bar is sewn on. If the top of the rafter is paired with a mirror-opposite counterpart, then for a reliable stop, you will need a gash, the plane of which must be clearly perpendicular to the horizon.

The basic rule in the construction of truss frames is that the support sites selected in the lumber are strictly horizontal and vertical. At the slightest violation of horizontality with verticality, stability is lost, structural parts are displaced under their own weight and load, up to the complete destruction of the system.

Note that the nodes of the truss systems are entrusted with the obligation to ensure the possibility of a slight displacement and rotation when the load is exceeded. These movements are necessary in order for the structure to bend slightly, move slightly, but not collapse and maintain stability.

These subtleties should be known both to the master who decided to do the manufacture and installation of rafters with his own hands, and to the owner of the house under construction, who does not want to pay for the poor-quality labor efforts of the builders' team. Let's analyze the common options to understand the essence of the process.

Hanging roof frame construction

Consider an example of the construction of a truss system over a log cabin of a bath. The span between the walls is small, it is easier and more reasonable to block it with a hanging structure, the installation of which will be carried out on the bypasses of the ceiling beams - matrices.

The log base is an almost ideal option for installing hanging systems, because. it is easiest to cut it into the horizon, eliminating the need to adjust the rafters in case of a violation of the geometry of the foot. There is no need for a Mauerlat device. However, the puff will have to be moved up in order to bypass the upper crown of the log house and form a useful attic space.

Before performing the installation of the rafters, a phased preparation of the log house is carried out. On both sides of the foot, we align the bypasses according to the lace tied to the nails hammered into the two extreme beams. On top of the bypasses, we cut off the slab so that the edge of each beam ends with a flat horizontal platform.

The surface formed after squeezing the upper bulge of the log along the edges of the beams is aligned to the horizon according to the level. We apply the specified control tool to three or more beams at the same time. If the level is not long enough to carry out such a check, use a long rail or board instead.

After squeezing all the excess, we mark the nests for the rafter tooth. To do this, we again use nails and lace. Note that it is possible to draw nest sampling sites on the bypasses both before the construction of hanging trusses and after. However, it is much more convenient to make nests before making rafters. They will help to carry out the fitting with higher accuracy.

To facilitate your work, it is advisable to find the center of the log house from the side of future tongs. At these points, it is recommended to nail along the control rail, one of the edges of which will indicate the axis of symmetry. You can do without rails if you already have some experience in the construction of roofs.

We sew two inch boards 10–15 cm longer than the designed length of the rafters at the top with a nail or bolt so that they can rotate around this connecting point.
On the rail installed in the center of the future tongs, we mark the design height of the truss system. We put one more mark above it - this is the height of the tooth, more precisely, the length of the vertical laid off from the base of the tooth to its top.
We set the boards sewn at one point to the extreme bypasses so that the corner of each board rests against the future socket under the tooth.
We combine the connection point of the boards with the upper mark on the rail, which determines the length of the rafters with the tooth.
From the lower corner of both rafters, we set aside the height of the tooth, return with the template blank to the ground and cut out the tooth according to the markup.
We return the template blank to its place, install it by inserting the teeth into the sockets intended for them. It may happen that after installation, the top of the workpiece does not match the directions of the rail. Then you need to pull out the nail and adjust the position of the top, be sure to mark a new point.
After fitting the top, we draw a vertical line of their upcoming joint on both boards, measure the size of the crossbar and mark on the trimmings of the board the shape of the overlays for the upper joint of the rafters.

If everything turned out exactly and no more adjustments are required, the template is ready. We return with him to the ground. We disassemble the workpiece and make cuts along the marked lines. The parts obtained as a result of fitting and fitting will serve as a standard for the practically in-line production of roof trusses in the required quantity.

We will assemble hanging farms on the ground. Their installation, as well as fitting, should be carried out by at least two people. One master simply can not cope with such work. The performer at the top will install the truss, and the second one will change its position according to the plumb line. The position of each leveled and installed truss should be fixed with temporary struts.

To increase the stability of the system, we will install racks under the rafters:

Let's mark the matrices under the place of installation of additional supports in an already proven way: we will hammer in a nail from opposite sides and pull the cord.
We will hollow out nests in the logs according to the markings.
Let's try a piece of a bar to the installation site. We mark on it the line washed down, taking into account the height of the spike.
We will make a rack and two linings for attaching it to the rafter.
Install the support made and fix the position of the truss truss on the other side in the same way. According to the verified scheme, we continue to work until we equip each rafter with an additional support.

To ensure the rigidity of the hanging system, the truss trusses are connected by wind ties - boards, poles or slats nailed from the inside of the structure. On the outside of the truss frame, rigidity will increase due to the construction of the crate.

The rafter legs are attached to the matrices with 200 mm nails or angle brackets. In this regard, metal corners and plates with perforation for fasteners significantly lose to traditional methods. To the sidewalls of the rafters we nail fillies made of a board, the width of which is half the material used in the manufacture of the rafters.

The length of the filly should be 70 - 80 cm more than the designed width of the overhang. This distance is necessary for their reliable connection with the rafter legs. The fillies can be cut in advance, or without preliminary cuts, you can nail the trimmings of a narrow board to the rafters, and then draw up the line of the eaves. However, the first option is more convenient and economical.

In most cases, as in the example above, fillies must be partially buried in the mats bypass, for this:

We note in fact the width of the filly at the bypass.
We make two cuts with a saw according to the markup for 2/3 of the thickness of the filly. We also saw the log between the extreme cuts with a saw. We refine the recess with a chisel, accompanied by a hammer.
We install the fillies in the formed recesses, sew them with rafters with nails 100 mm long.

Upon completion of the installation of all fillies in the last ones, we hammer in a nail. We pull the control cord and mark where to saw off the excess.

The device of the layered roof frame

In the construction of a truss frame using layered technology, there is much in common with the installation of a hanging structure. The fitting is carried out in almost the same sequence, so it makes no sense to describe the actions twice. The main difference is in the methods of forming the upper node, because the tops of the layered rafters have a support - a ridge run.

If at the top the layered rafters are tritely based on a ridge run, they are laid either with a run, i.e. parallel to each other, or with a strictly vertical joint, similar to the docking of hanging legs. However, in most cases, they try to fix the upper part with a notch or a vertical cut with a tight fit to the ridge beam.

There are schemes according to which the layered rafters are based not on the ridge, but on the side run. In such situations, the top is formed according to the hanging principle, and the point of support on the girder is made out with a corner cut.

Let us analyze the most popular option in private construction for the construction of rafter legs with support on the lower corner cut and on the ridge run through a vertical gash. Note that the maximum depth of the cut should not exceed 1/3 of the width of the board.

Option for marking with a construction square:

On the square, we mark the height of the roof and half the span on a scale. These values reflect the slope of the slopes and set the main angles. The proportions must be exactly maintained.
If further use of the square is not planned, then the delayed points can be marked with screwed bosses or short screws with screws, if planned, it is better with paint that is removed with a solvent.
We apply a square to the board laid flat with the side on which the height of the roof is marked. We draw a line according to the indications of the square - this is the line of the upper cut of the rafter - the section of its interface with the ridge run.
Cut along the marked line with a circular saw. Lay the board for sawing flat, as it should be when cutting in width. Longitudinal cuts are made with setting on the edge.
From the top of the formed angle, we set aside the length of the so-called diagonal. This is the distance from the junction point with the run to the outer edge of the Mauerlat or the upper trim, if a frame house is being equipped.
We move the square to this point. We draw a line parallel to the first.
We turn the square over, move it along the workpiece so that 2/3 of the total distance is on the left, and 1/3 on the right. In the picture, these are 8ʺ and 4ʺ.
The line of a smaller segment will just designate a cut for us.

At the end, we draw the outline of the cornice overhang on the board, cut it along the outlined lines and use the rafter blank made by ourselves to saw the rest of the roof elements.

You can apply the described method without a building square and marking the parameters of the roof on it. It is enough to imagine the process in order to set aside the necessary distances with a conventional drawing tool. However, without experience, you can get confused in the calculations of angles and segments.

To help novice builders, a template has been developed with options for forming corner cuts. It will help you navigate the manufacture of rafter legs from the most common lumber in this area.

In cases of laying rafter legs with notches in the upper and lower parts, it should be remembered that the depth of both notches must be the same so that the roof slope does not change during construction work. Usually, for the device of two equal cuts, an auxiliary bar is used, the thickness of which is not more than 1/3 of the thickness of the board.

The rafter blank is then installed with an edge on the Mauerlat and on the run. The bar is applied on the side in the area of the lower and upper nodes to outline the cut.

If the cut is needed only in the lower part of the rafter, and the top will be based on the run with a cut, the board is installed at the bottom on the Mauerlat, and at the top on the run and the bar, so that as a result of cutting, the slope of the slope does not change. At the bottom, a second bar of the same size is applied to the future node and the outline of the future cutting is outlined with it.

The same methods are used to form cuts with a tooth. The difference is only in the form washed down.

The installation of layered rafters begins with the installation of two extreme trusses. The elements are mounted one at a time, their position is carefully checked using a plumb line. Most often, extreme farms are arranged from paired boards, because. they carry more load. They are fixed with temporary spacers, then connected with a cord or rail to indicate the plane of the slope.

Ordinary rafters located between the extreme load-bearing trusses are installed according to the instructions of the laces. If necessary, correct the position of the legs according to the actual situation.

Video about installing rafter legs

Installation of rafters with fastening with metal corners:

How to make rafter legs with cuts for landing on a Mauerlat:

The device of the truss frame under the roof of the garage:

We have given and described only a part of the methods for constructing truss frames. In reality, there are much more manufacturing and installation methods. However, an analysis of the basic options allows you to perfectly understand how to properly make rafters and truss trusses for the roof, how to saw them down before installation.