Installation of the roof frame. Do-it-yourself rafter system for a gable roof: a review of hanging and layered structures

The most important process in installing a roof is building the frame. If miscalculations and shortcomings are made during its planning and construction, then such a structure will not stand for long. In housing construction this “skeleton” roofing structure mainly made of wood. Let's talk about how to do this wooden device durable and practical.

The frame is made taking into account the selected roof structure (gable, sloping, mansard, etc.), type of rafter system and characteristics roofing. The most common type is a gable roof. Therefore, as an example, let’s take the technology for constructing just such a frame. Once you master it, you can easily build a “skeleton” of any type of roof. The key stage in the process of building a frame is the so-called raftering of the roof. You need to understand: the reliability and stability of the entire future roof depends on how clearly the truss structure is calculated and its installation is carried out correctly. Therefore, the first and important stage of work is drawing up a drawing and competent design, taking into account all future loads.

Based on the type of structure of the rafter system, there are two main types of frames:

Hanging.
Layered.

The main difference between these options is the method of connecting the rafters. The first type of rafters rests at the edges on the walls of the building using a Mauerlat, and the second - on an internal supporting element (load-bearing wall). The upper parts of the layered rafters are not connected to each other. The most commonly used option is mounting using a Mauerlat.

The frame structure of the upper part of the building includes:

Elements of the rafter system – ridge beam, rafter legs corner and central rafters, vertical racks and so on.
Attic floor.
Lathing.
Mauerlat.

Therefore, at the second stage, take care of purchasing the material to create these elements:

For rafters - edged board with a section of 50×150 mm.
For the Mauerlat – timber with a cross section of 150×150 mm.
For the sheathing - slats with a cross section of 40x40 mm.

In addition, you will need:

studs for rafters and for the Mauerlat (with thread);
nails;
staples.

Do not forget to treat all wooden elements with special compounds - antipyretic and antiseptic. The first substance prevents the wooden parts of the roof from fire, and the second from rotting.

The installation sequence of the roof frame is as follows:

Attaching the Mauerlat to the surface of the load-bearing walls.
Manufacturing and installation of rafters.
Construction of the attic floor.
Laying the sheathing.

At the first stage of construction of the frame for gable roof install the power plate. As a rule, such a support for the “skeleton” of the future roof is attached to the concrete of the load-bearing walls of the building using metal studs. To prevent the beams from being exposed to natural influences, lay them flush, covering the wood with brickwork on the street side. Now you can start installation rafter frame:

Make grooves in the Mauerlat for attaching the rafters.
Install the ridge beam. In the future it will serve as a fixation upper parts rafter legs.
Install the end rafters first, and stretch the cord between their ridges. It will be the guideline for all vertical intermediate elements.
Insert the rafter legs into the holes of the Mauerlat and secure them with brackets and brackets.
The “overhang” of the rafters beyond the walls of the building should be within 40 cm.
Secure the bottom of the rafters with strapping. It will become the basis for the attic floor.
Attach the upper part of the rafters to the ridge.
Connect all the rafters together with studs.

Install all rafter pairs using the method described above and begin assembling the sheathing. When choosing its type (solid or in increments), be guided by the type of roofing material. For example, for metal tiles or slate, thinned sheathing will be required. To do this, nail the prepared bars perpendicular to the rafters with a pitch equal to the size of the slate or tile.

As you can see, with a responsible approach, you can assemble the roof frame yourself, right on the roof. This option is considered more budget-friendly compared to installing ready-made roof trusses. After all, their installation requires special lifting equipment.

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The use of a metal rafter system is most appropriate in industrial and public construction, for example, in the construction of workshops, storage facilities, supermarkets, swimming pools, train stations. Housing construction does not justify the purchase of such building materials, which are also difficult to transport.

From wooden structures metal carcass for the roof it is resistant to heavy loads, which helps to increase the rigidity and reliability of the entire roofing pie of the building.

If the length of the roof slope exceeds 10 m, then it is recommended to install the rafters from metal, which should be supplemented with the same purlins, ridge supports and Mauerlat.

How do metal rafters differ from other systems?

In construction, a combination of rafter systems is allowed, where both wood and metal will be used. It should be remembered that places where the metal roof frame is sheathed with wood can cause the formation of condensation, which leads to gradual rotting of the wood. To avoid such problems, all wooden elements are impregnated with a special composition and then insulated with roofing felt.

For insulation metal base it should be sheathed either from below or from above.
The insulation is laid on metal parts with a small gap so that during condensation, moisture does not penetrate into the insulation material.
When installing insulation under the rafters, the remaining roofing parts are fastened on top of it. Thanks to this design, heat is reliably retained in the attic.
A metal roof frame will last a very long time; in addition, the use of rafters of about 30 m in length is allowed.

The use of lightweight profiles for the construction of modern buildings

On this moment In construction, new technologies are being used that are aimed at constructing light truss structures in residential buildings.

These include galvanized cold-formed profiles, its advantages are:

resistance to destruction processes, including rotting and damage from insects;
high fire safety;
doesn't need constant antiseptic treatment;
such a metal roof frame is constructed, regardless of the time of year;
compliance of purchased parts with the specified dimensions, which reduces the amount of waste;
ease of installation - the work is performed with a drill and screwdriver;
the collapsible design kit allows it to be transported without expensive lifting equipment.

Thanks to similar rafters, significantly different from profile metal elements With a metal thickness of less than 2.5 mm, developers can save on the purchase of material.

Lightweight design does not increase the load on load-bearing walls and foundation, which also affects the reduction of the construction budget. Any craftsman with basic skills in such installation can assemble a gable roof frame. The work will not be particularly difficult also because all drawings of parts and their markings are thoroughly checked in production.

Along with the listed advantages, lightweight rafter structures still have a drawback - they act as a conductor of cold, which means they are difficult to insulate. Also, condensation often appears on them, which has a destructive effect on roofing pie. Based on this, it is still better to build residential buildings from wood.

Installation of a metal frame, watch the video:

How to properly install a frame

A metal frame for the roof is assembled from I-beams, angles, channels, which are made of profiled metal. The shape of these parts can be triangular, trapezoidal, rectangular or any other.

Being a construction High Quality, in particular, durable and practical for covering large spans, the frame has significant drawback– difficult to transport due to its heavy weight. The presence of this factor affects the need to order lifting mechanisms. Taken together, all the work done leads to an increase in cost, so metal rafters are very rarely seen in private construction.

With help metal rafters These trusses easily cover spans of about 50 m.
In most cases, the installation of such elements is carried out on top of rectangular trusses.
In industrial premises, the installation of rafter trusses is carried out with technological equipment, for example with beam cranes or overhead cranes.
Metal frame being laid hipped roof or any other roof supported from reinforced concrete columns, metal or concrete reinforced pads fixed to brick wall(read: " "). For this support part The steel truss is reinforced with a steel plate, and the reinforced concrete pads are reinforced with a metal embedded plate. The system is shown in more detail in the photo.
To make metal rafter assemblies, the individual parts are connected using steel gussets, which are welded or bolted.

Developers engaged in private housing construction still cannot do without metal rafter structures, the only difference is that they are based on hot-rolled bent pipes with round, square or rectangular profile. Thanks to such rafters, the entire system is much lighter, while its load bearing capacity remains the same. The explanation for the low weight of the pipes is the use of steel no thicker than 5 mm in production, which is several times thinner than the metal for other profile products.

One of the most important stages roof installations - production of a frame for the roof. If you make mistakes in the calculations and during its installation, it will not last long. When constructing residential buildings, the roof frame is most often made of wood. Therefore, many private developers are interested in the question of how to make a reliable wooden frame roof so that it lasts for the longest possible period of time.

In this article

Types of roof frame structures

It should be noted that the roof frame may differ depending on the roofing structure used, for example:

Frame rafter type - made of lumber, intended for pitched roofs buildings.
Reinforced concrete frame- made from special floor slabs, designed for flat roofing structures.
Metal frame - made from iron beams, used for arranging the roofs of industrial buildings.
Lumber frame- used in private housing construction for gable roofs.

Types of rafter systems

Depending on the type of roof, frames can be arranged in different variations.

For the manufacture of roof trusses it is used wooden beam with a minimum cross-section of 15x5 cm. After securing the individual components of the truss structure to each other and fixing them on the house, the sheathing is attached to the frame.

The structure of the rafter system can be hanging or layered. Both options are used in private housing construction. Their main differences:

In case of production hanging system rafters load-bearing beams rest against the mauerlat, which is arranged around the perimeter of the house without finishing. It is fixed to the load-bearing walls of the structure, on the outermost masonry on top. Mauerlat is an ordinary timber beam with a section of 100x100 mm. The rafter legs are fixed to each other on top of the truss using a ridge beam.

When using the layered version, the rafters on top of the trusses are not fixed to each other. In this case, the trusses rest on columns, the longitudinal center wall of the structure.

When choosing a design option for a rafter system, the dimensions of the building are of great importance.

You need to understand! Hanging rafter structures are used in the construction of roofs of buildings, the external load-bearing walls of which are located at a distance of up to 6 meters from each other. Layered systems can be built if this parameter exceeds 6 meters and there are supporting columns or a central longitudinal wall, which is load-bearing.

Materials, tools for making a frame

Before you start building a roof frame, you need to choose a quality consumables. To arrange the rafter system, wooden beams and edged boards are used. It is recommended to use building materials made from coniferous species trees, since it contains natural resin, which acts as an antiseptic that prevents wood from rotting. Wooden beams for making a frame must have a cross-section of 15x15 cm, parameters edged boards- 5x15 cm.

It is also necessary to remember that truss structure It includes not only rafters - purlins and racks are also installed under them, including attic flooring, sheathing, and counter-lattice. If attic space will be used as a warehouse, and there are no plans to turn it into a living space in the future, then 5x15 cm boards will be enough to cover the attic. But if the attic is being built, then you need to use timber with a section of 15x15 cm.

For the manufacture of sheathing and counter-lattice, timber with a cross-section of 4x4 cm is perfect. This building material can withstand the load of any roofing structure.

Necessary construction tools

Staples, brackets necessary for attaching rafters to the support beam.
Special metal studs for reliable fixation of the mauerlat (support beam).
Additional fastening elements - galvanized nails, studs, self-tapping screws.
Yardstick.
Plumb line (building level).
Saw on wood.
Axe.
Plane.
Electric drill.
Hammer.

Rules for installing the Mauerlat

It is necessary to understand that the Mauerlat is the main supporting structure for both the roof frame itself and the entire roofing system. It is the Mauerlat that will fully accept external loads on the roof and distribute them evenly between the load-bearing walls of the building.

This makes it possible to significantly extend the operational period of the entire structure, because in the absence of such timber, roofing loads will destroy the walls in certain areas. We can confidently say that the Mauerlat is a key supporting component of any rafter structure.

There is no need to arrange a mauerlat when logs and wooden beams are used as rafters, the outermost row of which performs these functions.

The described supporting component of the rafter system is mounted at the level of the walls with inside. This makes it possible to significantly simplify further Finishing work inside the building.

WITH outside the supporting element is covered with a metal strip and brickwork. This makes it possible to protect lumber from the adverse effects of the natural environment.

The top row of building blocks or brickwork requires the construction of a high-quality concrete blind area, which is subsequently covered with dense roofing material in several layers or a bitumen mixture. Roofing material will prevent moisture absorbed by the walls of the building from entering the wooden support beam.

The most reliable and simplest option is to attach the Mauerlat to the load-bearing walls of the building using specialized metal pins. IN building block When laying bricks, holes of the established diameter are made, then metal fastening pins are lowered into them (they are made from ordinary metal reinforcement). Next, a support beam is placed on the inserted studs, and the points of the holes that also need to be made in the beam are marked. The length of the stud is taken such that the reinforcing bar, after installing the Mauerlat, protrudes beyond the timber by at least 1.5 cm.

It is necessary to make threads at the ends of the reinforcing bars for final fixation of the support with nuts and washers.

The procedure for securing the support can be significantly accelerated using a standard welding device.

Arrangement of the rafter frame

The roof frame with your own hands should be made exclusively from dried building materials so that the wood does not subsequently become deformed.

The structure of the truss must include two rafter legs, respectively, connecting ties to fix their lower part. Bolts and anchor components are used to secure the tie to the rafter legs. The required number of trusses is attached to the Mauerlat. For their fastening it is used simple technique, which is as follows. You need to make grooves in the support correct form appropriate quantity. Next, using simple manipulations, rafters are inserted into the cutouts. The distance between individual roof trusses is selected based on the exact parameters of the roof, based on the size of the building. As practice shows, the distance between the rafters is usually no more than one meter. It is worth noting that some roof frames use vertical rafters. Similar items are used for arranging high roof structures with a vertical parameter of three meters.

The wooden lathing structure reliably connects the components of the rafter frame. But before installing it, it is necessary to ensure the stability of the trusses. For this purpose, a ridge beam is provided at the top of the structure. Temporary strapping is performed at the bottom of the structure, and after installing the sheathing boards (slats), it is removed. Lathing is of great importance not only when installing the roof covering, it is also necessary for the high-quality connection of all structural elements in the manufacture of the roof frame.

Lathing structures can be of a continuous or intermediate type in their design. The lathing option is selected depending on the type of roofing used building material. An intermediate version of the lathing is used when the roof covering is sheet building materials. In this case, the established distance is maintained between the slats.

When using a soft roof to cover the roof of a house, the sheathing is made continuous, since only on such a base is it possible to lay roofing material at a quality level, thus ensuring a longer service life for the roof. Exactly for soft tiles fits perfectly solid option lathing, and on the intermediate lathing structure soft roof will hang under the roof and will quickly fail as a result of poor-quality operation.

Important to remember! Wood is a flammable material and is susceptible to insects and fungi. To provide reliable protection from such unfavorable factors, all wooden elements of the roof structure are pre-treated with special antiseptics. Fire retardants are used to prevent wood fires. All these measures will significantly increase the service life of the roof frame.

Material options for building a private house on modern market a bunch of. The most common ones are brick, block and log. But in Lately Frame houses are becoming increasingly popular. They are simple and quick installation. You can do it yourself without resorting to the help of professionals. Below you will find recommendations on how to build a roof. frame house with your own hands.

The roof structure is heavy and rests on the load-bearing walls of the house.. In case of frame house the roof is installed on vertical posts covered with OSB boards up to the middle of the beam top harness. Decorative cladding walls are made after the roof is installed. And after this, the pediment and cornice overhangs are hemmed.

They are erected and sheathed before the roof is assembled. Therefore, before starting work, you need to prepare a project where it will be determined appearance roof and its slope. The pediment can be attached in parallel with the installation of the roof, but first you will still have to install the outer trusses, securely secured using braces.

The roof height of a frame house is usually more than 6 meters. Before starting work, you need to decide on the type of rafter system. Depending on the width of the span to be covered, the rafters may have a ridge board, a support screed or sloped braces if there is a central load-bearing wall. If the span is small, then rafter ties are usually installed. Attic walls can act as a supporting screed.

The rafters are secured using nails, self-tapping screws, metal plates or angles. The pitch of the rafters is determined within the range of 40 - 100 centimeters. This figure depends on the section size wooden beams, from which the racks are made. They can be within 2.5 - 5 meters.

Wooden blocks with a cross-section of 10x10 centimeters, called mauerlats, are laid on the external load-bearing vertical posts of the wall to support the rafter legs. Required condition its settings are rigid fixation. It is best to connect the rafter legs using serrated overlays. If the overlapped span is more than five meters, it is necessary to install a special support under the rafters. After installation, the sheathing is installed to lay the roof covering. It can be made of OSB boards, plywood, edged, half-edged or unedged boards. This depends on the chosen roofing covering.

Subject to availability attic floor, the roof must be insulated. The insulation is placed between the rafters. Provided that its thickness is 10 - 15 cm, the cross-section of the rafters will be 15x5-15x7 cm. The cross-section of the rafters is selected according to the thickness of the insulation and the amount of snow load. To do this, calculations are made. If it is not possible to carry it out, then take a larger section of rafters. If the insulation thickness is more than 15 cm, rafters with a section of 20x7 cm are suitable.

When installing rafters on the mauerlat, a triangle equal to 1/3 of the rafter height is cut out in the support bar.

The roof may have one or more slopes. Wherein complex roof looks more interesting. But the best option, both in terms of the amount spent and the work carried out, would be a gable roof. It does not have valleys and has only one ridge, which will be a definite advantage when building a roof with your own hands, since these places in the structure are the most vulnerable.

When choosing the slope value, it is worth considering that with an indicator of less than 28 degrees, the load on the rafter system increases. This will lead to the need for strict calculation and control over load-bearing elements. And with a slope exceeding 50 degrees, wind loads increase. Optimal choice there will be a slope of 35-45 degrees. Such a roof will look better, and snow will not linger on it.

Roof installation

Let's look at roof installation using the example of a house with overall dimensions of 6x8 meters, a gable roof with a slope of 45 degrees, where bitumen slate is used as a roofing covering. The design includes an attic floor with a wall height of 1.1-1.6 meters.

The height of the walls of the attic floor should not be less than 1.1 meters. This will cause inconvenience during the operation of the under-roof space. In a cold attic, there is no need to raise the walls, and the roof structure will not change.

As a rafter system we will use two inclined rafter legs connected by a crossbar to ensure rigidity. It is also called a tie, jumper, cross member, etc.

The presence of an attic floor requires. Therefore, we will choose the parameters 15x5 cm as the cross-section of the rafters. And we will take the thickness of the insulation 15 cm (according to calculations for Moscow - 138 mm).

Next you need to decide on the length of the rafters. This can be done by making calculations. First of all, you need to decide on the angle of inclination. If you don't yet know which inclination to choose, follow the instructions below

Two slats 6 meters long need to be knocked together using nails in the shape of the letter “L”. This will clearly show what the roof truss will look like. The work is carried out on the ground. After this, it is worth preparing a test crossbar. It is a long strip that is applied to the rafters to measure its length.

After this, we lift the resulting truss onto the roof and rest it on the beam of the upper frame. Next, using the selection method, we determine the angle of inclination and, accordingly, the length of the rafters. When determining this parameter, it is necessary to take into account that the overhang of the rafters relative to the wall should be 30-55 cm.

The roof overhang is made to protect the walls of the house from precipitation. If there is no drain, the overhang should be at least 50 cm.

With this method of selecting the length of the rafters, it is necessary to take into account that the final height will be 5 cm lower due to installation on the mauerlat. To make such an installation, a rectangle of 5x5-5x6 cm is cut out of the Mauerlat bar for rafters with a cross-section of 15x5 cm. And when trying on the rafters, it is necessary to mark where the support will take place and draw a vertical line. Thus, we will mark one side of the triangle, and mark the other on the ground at an angle of 90 degrees.

The pitch of the rafters is determined depending on the cross-section of the rafters and the roof slope. For the example under consideration, a step of 70-80 cm is best suited.

The next stage is preparation required quantity rafter legs. To do this, we use the already marked roof truss. This work should be carried out on the ground. We mark each subsequent rafter leg according to the first sample to prevent the accumulation of errors.

Then we proceed to fastening the crossbars. Best place for their placement - as low as possible. The crossbar is necessary to perceive the thrust, and the lower it is, the better it works.

In the presence of an attic floor best height fastening of crossbars – 2.25 – 2.35 meters. This will allow you to place doorways 2.1 meters high. When reducing the height of the openings, the crossbars can be placed lower. But at the same time, the height of the premises will be correspondingly lower. To make the height of the premises equal to 2.5 meters, which is considered the most convenient parameter, the crossbars are made at an identical height of 2.5 meters.

The presence of a counter-lattice will provide a gap for ventilation in the roof. There should be two of them - a lower and an upper ventilation gap, each 2-4 cm high. This is done regardless of whether the roof is insulated.

The lower ventilation gap is made under the waterproofing layer, and the upper one is made above. They allow condensation to evaporate and prevent water accumulation. The presence of both ventilation gaps will ensure that the wooden elements do not become covered with mold or mildew.

The counter-lattice is attached to the rafters lengthwise. The pitch for them is chosen in accordance with the pitch of the rafters. The cross-section of the boards for these purposes is 2x5 cm.

Next we attach the sheathing. The size of the section and pitch will depend on the selected roofing material. According to the conditions of our example, this is . Therefore we choose unedged boards for sheathing with a cross-section of 4x5 cm. And we will install them in increments of 35 cm.

We select the length of the sheathing taking into account the presence of an overhang beyond the outer rafter leg of 20-50 cm. It can be equated to the overhang of the rafters.

Material selection

For roofing works undried wood is suitable (sometimes called wet wood). You can buy it at the sawmill. When choosing, pay attention to appearance. If the wood is gray, this may indicate the presence of fungus. Undried wood will require less financial investment than dried wood, since its price depends on the cubic meter rather than the square meter.

After purchasing, be sure to remove the bark from the wood - this will prevent the formation of bark beetles.

After calculating the roof elements, you should order the material. It must be taken into account that standard length lumber will cost less. And you can trim them yourself, using the leftovers for something else.

The roof frame of a house is one of the key elements the buildings. And if the frame is erected taking into account all the rules and compliance with construction standards, then there is a high probability that this building will serve its owners faithfully for decades.

Arrangement of the foundation and construction of the walls of the house is approaching the finish line, and novice builders are faced with the question: how to build the roof of the house? In fact, the choice of roofing and waterproofing materials is quite large, and you can always purchase it taking into account your financial capabilities. But the roofs of the house demand special attention. First, you will need to decide what kind of roof you see and choose its type: single-pitch, gable, hip or sloping.

There are many advantages to making your own roof frame. Firstly, you will have great opportunity save on payments for hired craftsmen. And secondly, you yourself will control the entire construction process and will be able to prevent possible repair work in the future.

Once you have decided on the type of roof you want, you can safely begin building it. As an example, the process of constructing a gable roof frame is given, since this type is the most common among most private house buildings.

Choosing a rafter system

As you know, absolutely any rafter system is a connection of two rafter beams at the top of the structure. In the lower part of the structure, the rafters are secured due to the presence of a lower tie, and it can serve as an additional support that secures the integrity of the structure.

There are two main types of rafter systems: inclined and hanging. It is the inclined rafter system that is used in the construction of private housing. The choice of rafter system is usually determined by some design features the building itself. So, for example, if the distance between the two main load-bearing walls of the house is at least 6 meters, you can safely install a hanging rafter system. Then the main load-bearing mass will be taken over by the walls of the house. If the width between the walls is more than 6 meters, then there is a high probability of subsequent sagging of the rafters. In this case, care must be taken to install additional support.

Choosing material for a durable frame

Before making the roof frame, it will be useful for you to decide on the choice of material.

Wood is used as material for rafters, namely edged boards and timber. It is best to give preference to coniferous wood, since this material contains resin, which acts as a kind of natural antiseptic that prevents rotting. The size of the edged board must correspond to the following parameters: 50x150 mm, and the size of the timber - 150x150 mm.

Also remember that the rafter system consists not only of the rafters themselves, the racks and the purlins for them. These also include attic floor, lathing and counter-lattice. If you plan to use the attic as a warehouse and do not plan to make additional living space out of it, then boards measuring 50x150 mm are quite suitable for the attic floor. And if you have always dreamed of an attic, then you should purchase timber measuring 150x150 mm.

For counter-lattice and sheathing, a beam measuring 40x40 mm is suitable; this is quite enough to support the weight of any roof. The main requirement for such material is that it is sufficiently straight, because if the timber has deviations, the sheathing of the frame will turn out uneven and the weight of the roof will be distributed unevenly.

Necessary equipment

In addition, you will need following materials and tools:

special metal pins, which, thanks to their threads, securely fix the support beam (mauerlat);
brackets and brackets for fixing the rafters to the support beam;
various fasteners (galvanized nails, self-tapping screws and small diameter studs);
drill;
saw;
hammer;
roulette;
axe;
plane;
level or plumb.

Stages of constructing a roof frame

The main stages of constructing a roof frame for a house are as follows:

Wood processing. Since you will not have the opportunity to process lumber in the future, it would be best to do this at initial stage construction work. The material is treated with two compounds. The first, an antipyretic, can reduce the flammability of wood. The second, antiseptic, helps prevent rotting wooden elements. Remember that after processing the lumber must dry thoroughly.
Installation of the Mauerlat. Mauerlat is usually called a beam that acts as a support for the entire frame structure. It must be laid directly on the load-bearing walls of the house. And its main function is to evenly distribute the load associated with the weight of the roof.
To lay the support beam, it is necessary to erect a solid concrete blind area along the perimeter of the entire building. After drying concrete screed it must be laid on its surface in several layers waterproofing material, roofing felt is perfect for these purposes. Next, special metal pins with a diameter of at least 10 mm are installed in the concrete blind area. After that, the support beam is “put on” the installed studs; to do this, holes must be drilled in it in advance. Remember that the ends of the studs will need to protrude at least 10mm. Subsequent fixation is carried out using nuts.
We install the rafters. Experts advise: if you work alone, then to make the work easier, it is best to assemble the rafters on the ground. If you have an assistant, then you can safely assemble the structure directly on the roof of the house. First, you need to make grooves in the support beam for installing the rafter legs. The distance between the grooves must be determined in advance, based on the dimensions of the structure itself, but they should not be more than 1.5 m. Otherwise, the structure will have insufficient rigidity.
Rafters are installed from the front-end part of the building. Then you need to pull the cord between the ridges of the two end rafters. Thanks to this technique, it will be easy for you to navigate while aligning the vertical of the remaining intermediate rafters.
Next, the rafter legs must be inserted into pre-prepared grooves. Fastening is carried out through the use of complex fastening: transverse and longitudinal. Transverse fastening is carried out through the use of steel brackets, and longitudinal fastening is carried out through the use of special brackets that securely fix the rafters to the mauerlat. When installing the rafters, make sure that they extend beyond the perimeter of the building by about 40 cm.
We fix the lower part of the rafter system using strapping for these purposes - the base of the attic floor. If necessary, the harness can be extended with additional beams, laying them overlapping.
The rafters must be connected to each other by two pairs of studs. The presence of two, rather than one, studs is due to the fact that when fixed with one fastening element, the rafters will rotate around their axis.
We give the structure greater rigidity and install an additional cross beam. Now the rafters will outwardly resemble the shape of the letter A; this technique is relevant in cases where the distance between the walls is more than 6 m. The dimensions of the transverse beam can be following values: 50x150 or 50x100 mm. Fixation is carried out using self-tapping screws.
We install the ridge beam at the top of the rafters. If necessary, you can strengthen the upper unit with an additional cross beam.
After all the rafters have been erected, you can safely proceed to the lathing and counter-lattice. Today there are two options: thinned and solid, depending on what roofing material you plan to use. Thinned sheathing consists of horizontally packed beams on rafters with a certain distance. Any roofing material of increased rigidity (slate, corrugated sheeting, etc.) can be laid on such a sheathing. With continuous sheathing, sheets of moisture-resistant plywood are placed on the surface of the rafters; this design is excellent for laying soft covering(roofing felt or any other rolled roofing material).