Do-it-yourself rafter system for a gable roof: an overview of hanging and layered structures. How to install rafters on the roof Methods for installing the rafter system

When constructing private houses, the roof is most often made of a gable roof. There are reasons for this. The first is that it is reliable. Copes well with wind and snow loads. Secondly, it is compatible with any roofing covering. The third is relatively inexpensive. The fourth is not complex design, which is difficult to spoil. Fifth - she looks attractive. All this, and also the fact that a gable roof is built with your own hands without the presence of special knowledge, determines its popularity.

The assembled gable roof with your own hands is ready for installation roofing

Step-by-step installation of a gable roof

As you saw above, there are a lot of rafter systems. Accordingly, each assembly has its own characteristics, but in general order same. It is necessary to talk about the general step: pre-drying and processing of wood. This step is required if you bought fresh lumber rather than dried.

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

Lumber should be dried in ventilated stacks. To do this, they are laid with short sections of boards. They are placed a meter from the edges and then every meter. Spacers must be installed under the lower one

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

Mauerlat

Assembly of the rafter system begins gable roof from installing the Mauerlat. It must be positioned strictly horizontally, therefore, before installation, the horizontality of the wall to which it is attached is carefully checked, and if necessary, it is leveled cement mortar. You can continue work after the solution has gained 50% strength.

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

There are several ways to connect walls and mauerlat:

• Smooth rolled wire is fixed in the masonry (in the reinforced concrete belt) large diameter(two ends sticking up). The board is then done in necessary places holes through which the wire is threaded. It then curls and bends.
• Studs with a diameter of at least 12 mm are immured in the wall. Holes are made in the Mauerlat for them, a timber/board is inserted) and tightened with nuts and wide washers.
• Having aligned the beam or board along the outer or inner edge of the wall, take a drill with a diameter of 12 mm and make holes for anchor bolts. They (the same diameter of 12 mm) are hammered in to the very top, then tightened with a wrench.

The distance between the studs (wire) should not be more than 120 cm. A cut-off waterproofing must be installed on the wall (belt) under the Mauerlat. This can be rolled up roofing material or waterproofing material in two layers, or coated with bitumen mastic.

Installation of rafters

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

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

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

On the one hand, this is convenient - it’s easier to work on the ground, and with a high assembly speed, the accuracy is high: one truss is not much different from the other, which simplifies the procedure. But lifting prefabricated trusses can be difficult, especially for large buildings. To make this easier, install two slanted boards, which at one end rest against the ground, and the other sticks out slightly above the wall. The trusses are brought closer to this “lift”, one at a time they are installed below, ropes are tied and pulled along the boards onto the roof. If there is no winch or crane, this is the most acceptable method.

Assembling rafters requires certain knowledge: how and in what order to install them, how to mark and make cuts. Watch the video for assembling one of the headstock circuits.

The procedure for assembling the rafter system

That’s it, the do-it-yourself gable roof is assembled and ready for installation. roofing material.

The process of installing rafters itself raises enough questions, but there are many ways and it is impossible to tell about them all. Watch one of them in the video. The system was large and was lifted to the roof in parts, and then assembled into a single structure. This is convenient for large houses.

Features of installing the rafter system of a wooden house

Difference wooden houses is that the log house shrinks, and this leads to a change in the geometry of the rafter system. If the elements are fastened tightly, the roof may fall apart. Therefore, the fastenings are made floating. There are special sliding fasteners, which in this case are used to secure the rafters to the upper crown and to the purlins, if any (see photo).

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

Such fasteners are sold on any construction market, they are called “slipper”. Watch the video to see how to attach the slider to the beam.

Video on assembly and installation of gable roof rafter system

Building a gable roof with your own hands is not easy: there are a lot of subtleties and nuances, there are different methods of fastening and extension. Describing them in words is a thankless task. This is the case when it is better to see. Below we offer you a selection of videos that may be useful to you.

Video report on how a gable roof is made

The house owner's story about the stages of construction. There are interesting technical points, which may be useful.

Two types of rafter connections: rigid and sliding

Video about the two most problematic types of connections.

How to determine the angle of rafters

Full video report on the assembly of the rafter system

This film takes just under an hour, but the process is demonstrated from start to finish in great detail. The roof is placed on, but when installed on buildings of another type (except wooden houses) there is no difference.

Installation of rafters is one of the key stages of roof construction. To ensure that the rafter system does not deform or collapse under high loads during operation, the rafters must be properly secured.

Calculation of rafter pitch

When designing a rafter system, this issue is given Special attention. The strength characteristics of the roofing system depend on the cross-section of the rafters and the pitch of their installation.

The rafter pitch is the distance between adjacent rafter legs. The minimum pitch of the rafters is 60 cm, the maximum is more than 1 meter. A simplified version of calculating rafter pitch involves using the table:

The length of the eaves slope must be divided by the rafter pitch selected in the table, then add one to the resulting value and round up to a whole number. The resulting result means required amount rafter legs per slope. Then the length of the slope along the eaves should be divided by the calculated number of rafter legs - the final number corresponds to the value of the center distance between the rafters.

This calculation method is general; it does not take into account the specifics of roofing coverings and the type of insulation used. If you intend to lay a roll or slab insulator, it is recommended to adjust the pitch of the rafters to the size of the material. It should be taken into account that the width of the cotton insulation should be 1-1.5 cm greater than the span between the rafters.

When determining at what distance to install the rafters, you should also pay attention to the recommendations for installing the selected roofing covering.

Preparation of material

Installing rafters with your own hands requires not only knowledge of the process technology, but also proper preparation wooden elements systems for installation. The rafters are made from edged boards or timber, the cross-section of the lumber is selected at the roof design stage. The tree should not have cracks, wormholes or other damage.

Rafter legs should be made of well-dried wood coniferous species to prevent their deformation.

Wooden elements must be treated with fire retardant and bioprotective compounds. Before you begin installation, you need to decide on the method of attaching the rafters to the mauerlat or beams, and the type of ridge connection. In accordance with the project, metal and wooden fasteners are selected, including:

• plates (made of metal or wood);
• bolts or studs with nuts and wide washers;
• nails, screws, staples, etc.;
• wire rod.

Types of rafters and features of their installation

When constructing the roof of a house, hanging or layered rafters are used. In some cases, a combination of both may be used. Hanging ones rest only on the walls of the building, and layered ones require the installation of additional supporting structures, so this option is primarily used if there is a middle load-bearing wall or support pillars inside the building box.

The lower part of the layered rafters rests against the mauerlat; accordingly, the walls of the structure must have sufficient width for the installation of a special supporting structure made of timber with a section of 150×150 mm. The upper part of the layered rafters rests on ridge run. Thus, the installation requires the installation of a purlin, for which middle wall or pillars, racks should be mounted.

Hanging rafters rest only on the walls. This design can be mounted both on the Mauerlat and on thin walls without laying the Mauerlat. In this case, the support for the lower part of the legs is provided by floor beams protruding beyond the plane of the wall on both sides of the building. Hanging rafters are connected by a jumper (tightening, crossbar) which relieves the pushing forces. When covering large purlins, the trusses are strengthened additional elements to enhance the rigidity of the structure. When installing hanging rafters on a mauerlat, a low-lying tie can serve as a floor beam.

Before installing the rafters, it is necessary to mount the scaffolding. This makes it possible to ensure the necessary safety and convenience of work.

Installation of the upper ends of the rafters

When choosing how to install rafters, it is important to evaluate the complexity of the work and weight truss structures. If the farm is in assembled form has a relatively light weight, or it is possible to use lifting equipment, then the structures are easier to assemble on the ground, and then lifted and mounted on the roof. If the elements of the system are heavy and have to be lifted manually, then the trusses are assembled on the roof. About installation technology roof trusses explained in the video instructions.

The connection of the upper ends of the rafters can be done different ways. First of all, this is a butt mount. On the opposing rafter legs, cuts are made at the desired angle. Then the rafters are joined with the resulting ends and attached to two nails. The connection is further reinforced with a wooden or metal overlay.

Attaching the rafter legs with an overlap is done using bolts or studs with wide washers and nuts. In this case, the rafters are in contact with the planes.

If the rafter system is mounted on wooden house with gables made of timber or logs, it is necessary to install rafters on the walls using sliding fasteners to avoid deformation of the roof during shrinkage of the structure. Accordingly, in the ridge part, the rafters must be connected in a special way: the rafter legs must be positioned with a gap, and they are fastened together using a special movable metal connecting element.

If there is a ridge beam, installation of rafter trusses on the ground is not required - the rafter legs are installed one at a time and attached to the ridge girder.

The ridge run must be positioned strictly horizontally so that the rafter system evenly distributes the load experienced by the roof.

Methods for installing rafters on walls

The lower ends of the rafters are attached to beams or mauerlats. The hanging rafter trusses, assembled according to a template, rise to the roof. The outer trusses are installed first. It is necessary to make two or three holes in the tightening to attach the rafters to the beams laid on the upper crown of the frame.

If hanging rafters are mounted on stone building, you need to use special fasteners - the so-called “ruff”, made of durable steel. This fastener is driven into every fourth row brickwork. Using the loops extending from the ruff, you can secure the beams. It is recommended to use a strong beam as a mauerlat - in this case the load will be evenly transferred to the walls.

On buildings made of brick or other material that is not prone to shrinkage, the rafters should be firmly secured. To do this, a cutout is made in the rafter leg, the lower part of which should lie firmly on the Mauerlat. The rafter is fixed with three nails (two are driven in on both sides at an angle, and the third vertically from above) and tied with wire. A connection using corners and a support bar can also be used to prevent the rafters from shifting.

Proper installation of rafters involves making a fire break in the place where the roof passes chimney. If its arrangement involves the installation of a special rafter system, this should be taken into account when installing a shortened rafter leg (from the Mauerlat to the chimney structure). Between structural elements and the pipe the distance must be at least 130 mm.

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The rafter system is the supporting load-bearing frame for the roof. That is why it must be reliable, since the durability of the entire structure directly depends on the quality of the material from which the system elements are made, and the professionalism of its assembly.

It is quite possible to manufacture and install it if you have a craftsman nearby who has dealt with similar work more than once. Without experience in this work and a reliable adviser, it is dangerous to undertake it yourself - it is better to entrust this undertaking to a team of qualified craftsmen. However, if you still decide to try your hand, then you need to approach all the details of the system with all responsibility and caution, since the work is not only difficult, but also quite dangerous.

Requirements for rafters

In order for the entire roof system of the house to serve for a long time, dried coniferous wood is selected for the manufacture of its elements. For the rafters you need a beam with a size of 100÷150 × 50÷60 mm.

Coniferous wood is light in weight, which is beneficial for the entire construction of the house, since a heavy rafter system, creating a lot of pressure on the walls, can lead to their damage and destruction.

Another advantage of coniferous material for constructing a roofing base is high percent cm of foliage in its structure, which means an increased ability to withstand atmospheric moisture.

To manufacture elements of the rafter system, it must meet certain requirements that directly affect the durability of the entire structure:

• The wood for installing the rafter system must be seasoned, which will eliminate the risk of its deformation in the structure.
• Wood moisture content should be no more than 2-2.5%.
• If a hanging rafter system is being installed, then for the tie-downs and the rafters themselves, be sure to use only first-grade wood.
• When constructing a layered system, the second grade of material is also suitable.
• For supporting elements - racks and struts, you can use a third grade of wood, however, trying to choose raw materials with a minimum number of knots.
• The exact thickness of the blanks is selected depending on the weight of the selected roofing material and weather conditions in this region. Especially it concerns maximum thickness snow cover in winter period. For example, for middle zone Russian regions, it is necessary to calculate the load per 1 kv.m. roofs 180÷200 kg.
• In addition, the parameters of the rafter legs depend on general sizes rafter system and its slope.
• Before installing the system, the wood must undergo antifungal and fireproofing treatment.

When installing the structure, you need to know and types of loads that the entire roof system is subjected - they are also taken into account when choosing rafter parameters and installing the structure.

• Temporary loads are the weight of a person at repair work roofs, snow cover in winter and the strength of wind gusts.
this is the weight of roofing, insulation and insulation materials.
• Special types of loads include seismic impact if the structure is located in earthquake-prone regions.

General design of the rafter system

The most widespread The rafter system has the shape of a triangle and is intended for arrangement. It includes several triangular elements consisting of two rafter legs and auxiliary supports and ties. Each such triangular structure is called a rafter. The triangular elements of the system are located at a certain distance from each other, and most often it ranges from 50 to 80 cm.

This form has become traditional, as it creates better rigidity and reliability of the structure. It can end at the level of the walls or be continued to install overhangs, which can be 40 centimeters or more in length. Sometimes rafters ending on the walls are extended with additional bars - “fillies”.

So, as mentioned above, the rafters are one triangular section, including:

• Two rafter legs connected on a ridge beam, or without its use, directly to one another.
• Struts or rafter legs are spacers that support the rafter leg and relieve the load placed on it. They rest against the bed and are secured to it.
• Racks or vertical supports consisting of bars. They, like the spacers, support the rafter leg, but closer to the center of the triangle. The stand is installed on a bench.
• A crossbar is a board that holds two rafter legs together.
• The scrum is two crossbars attached to both sides of the rafter leg. It performs the same task as the crossbar - it gives rigidity to the structure.
• Headstocks are a vertical block that is supporting and is installed in the middle of the triangle, resting against the floor beam and supporting the ridge. This part is used in hanging systems ah rafters.
• Purlin - it connects individual rafters in common system. They are located parallel to the wall.
• Ties are floor beams that connect the rafter legs, completing the rafter triangle.
• - a powerful beam installed at the upper end of the wall structure, to which elements of the rafter system are subsequently attached.

There are three types of rafter systems - layered, hanging and combined, i.e. including elements of both one and the other.

Hanging system

The hanging rafter system is used to cover buildings without internal main walls. The rafter legs are laid on a mauerlat attached to load-bearing walls Oh.

Since such a system experiences a large load, which is transferred to the load-bearing walls, the following additional elements are used to relieve this stress:

• A tie that simultaneously acts as a floor beam. It can be used for flights up to 6 meters. If the span is larger, then it is raised higher along the rafter leg, and in the lower part the triangle is also closed with a floor beam.
• The headstock supporting the ridge is required if the span between the load-bearing walls is more than eight meters.
• Struts extending from the headstock at an angle and supporting the rafter legs.
• Help that strengthens the rafter leg.
• A ridge beam is required in this system.

All elements are fastened together metal corners, staples or screws.

Layered system

The layered system is more stable and reliable, thanks to additional supports in the form of permanent partitions inside the building. Their presence makes it possible to make attic extra room.

When making such a decision, the racks in the rafter system are installed closer to the load-bearing walls, freeing up space.

In this system, the rafter legs are installed on a mauerlat, which is secured to the side load-bearing walls. To ensure reliable installation, special grooves are cut into the rafter legs, and the elements are fastened together with staples.

A ridge beam in this system is desirable if there is a large span between the load-bearing walls, and it is planned to arrange a living space in the attic. The same applies to the ties, which in this case are fixed at the ceiling level of the future room.

You also need to know that the Mauerlat must be very securely fastened to the wall with pins going 350÷400 mm deep into the wall, since it bears a large weight and dynamic load from the entire rafter system.

If it is assumed that capital walls buildings may shrink slightly, then the lower parts of the rafters are attached to the Mauerlat with sliding fasteners, allowing the element to take the desired position without causing harm to either the walls or the entire rafter system.

Video: installation of a gable roof rafter system

Prices for various types of timber

Installation of truss structure

Having prepared suitable material and having a design for the roof structure, you can begin its installation.

Gable roof

On load-bearing walls, mauerlat bars are fixed to a pre-laid waterproofing material - roofing felt, and the installation of rafters is marked on them. It is very important to mark the two sides of the installation equally, otherwise the rafters will be skewed.

• The first rafters are adjusted and rigidly fastened directly at height, so as not to make mistakes in fastenings and in selections for installation on.
• Then, they are lowered down, and all other rafters are made according to the first sample. On the ground it is much easier and safer to fit all structural elements to each other and make reliable fastenings.
• When sawing timber for rafters, you need to leave a small margin, i.e. make them a little longer than required so that you can adjust them to fit.
• To make it easier to navigate, when setting up the first rafters, take a beam whose length is equal to the distance between the outer edges of the walls - this will be the base or hypotenuse of the future triangle.
• The middle of the block is determined, and a perpendicular board is temporarily nailed to it, having a height from the front wall of the structure to ridge - peaks equilateral triangle.
• Then they are laid out and secured sides - legs triangle, they are also rafter legs.

• If a hanging rafter system is chosen, then the ties are immediately marked and secured.
• If it is intended to install additional fasteners, then they are fixed in place after installing the rafters on the roof.
• Next, the first rafters are first raised and temporarily installed. On each of them, places are marked where rectangular selections will be made to secure them to the Mauerlat.
• Then, the rafters are lowered down again, and grooves having a right angle are cut out on them.

• Using the first pair, taking it as a sample, the same grooves are measured and cut out on the remaining rafters.
• Next, two triangles are climbed onto the walls, which are installed at the beginning and end of the future. If a ridge beam is provided, then both installed parts are immediately connected with it.

Video: how rafters are attached to the Mauerlat

• Along each slope, cords are stretched between the already mounted rafters, which will also serve as guides for aligning the remaining parts of the structure.
• First installed rafters are immediately reinforced with racks, struts and other elements of the system that provide rigidity and reliability of the structure.
• Next, the remaining rafter pairs are raised and installed.
• If necessary, they are connected to each other by purlins and beds.
• When installing a rafter system, all its elements are fixed temporarily, since some of them may have to be adjusted and reinstalled later. They are firmly attached only after the entire system has been aligned. Then corners, brackets are used for fastenings, and, if necessary, sliding elements. Self-tapping screws, nails, bolts, staples and studs are used at various joints.

If necessary, the rafters can be extended with “fillies”

• After the system is basically installed, the rafters can be “filled” on the overhangs - this is done so that the walls of the building are as well protected as possible from moisture getting on them during rain.
• The next stage of work is the installation of lathing on top of the rafters. The thickness and width of the boards for this part of the structure are selected taking into account the installation technology of the selected roofing material - this will depend on the width, weight and length of its sheets.

Video: installation of a gable roof rafter system

Prices for various types of fasteners for rafters

Rafter fasteners

Single slope systems

It is generally accepted that a lean-to system is used only when constructing roofs for garages, sheds, gazebos and other non-residential buildings, but this is not at all true. This type of roof also serves well as a covering. residential buildings, and you can even arrange an additional warm room under it if you correctly calculate the slope of the structure.

A shed system can be considered as half of a gable roof, but with some deviations. For example, if when installing a gable roof, the gable part is the width of the building, then with a shed roof it is its length.

The pediment can be raised from brick or wooden beams and boards. Its height will depend on the selected roof slope. The roof gable is raised high if an additional room is built underneath.

Rafters in this system are easier to lay, but if the distance between the walls is large enough, then it is still necessary to install additional supporting elements for rigidity.

To correctly determine the desired slope angle, you need to rely on the following factors:

• Snow depth in winter and average precipitation in other seasons.
• The weight of the roofing covering that is planned to cover the rafter system.
• Temporary loads, in the form of gusts of wind.

The angle of this type of roof can vary from 5 to 45, and sometimes there are buildings with an angle of even 60 degrees.

Installation of the single-slope option is carried out on site, i.e. at a height, since the gable and rear walls of the building serve as supports for the rafters.

If the roof slope in a one-story mansion is not too large, then the rafters can be extended forward from the front or rear side of the house. This is done in order to arrange a veranda or terrace under the roof.

Attic systems

The most complex to implement are mansard roof systems.

If the project immediately includes making the attic of the house residential, then you can choose one of two roof designs. The choice will depend on the desired attic area and ceiling height. It can be a gable roof with a high ridge or a broken mansard roof.

Gable roof

In order to arrange an additional room under a gable roof, the space must be free from various additional fastenings. Therefore, you will have to make do with a minimum number of them.

Stands and ties will be mandatory in this design - they will also perform the functions of the sheathing on which it will be attached. finishing material walls and ceiling of the created room.

But in this case, it is very important to use massive beams for the floor beams, which will easily support the weight of the rafter system with insulation and roofing material, plus the entire load given by the pieces of furniture that will be installed in the room. In addition, it is necessary to install the floor beams at a short distance from each other, which should not exceed 50 ÷ 60 cm, but in order for the walls of the building to withstand the entire load without problems, they must be quite massive and strong.

Installation of the system takes place in the same sequence as a gable roof.

Attic “broken” structure

The mansard roof structure of a house is more complex than a conventional gable roof, but its advantage is that living space, which is obtained as a result of its installation, will be much larger, and the ceiling will be higher.

Approximate diagram of an attic “broken” system

This type of roof is called broken, since the system consists of two parts, in each of which the rafters are located at a different angle.

The side rafters can be located at an angle of 30 or 45 degrees from the vertical - this is the most common option for their installation.

The top is fixed at an angle that can vary from 5 to 30 degrees from the horizon.

IN attic structure Both rafter systems can be used. It is preferable to arrange the lower rafters using a layered system, but if the building does not have permanent partitions, then a hanging system can also be used. In the latter case, beams attic floor, as well as the rafters, should be installed at a distance of no more than 50-60 cm from each other. It should be noted that the walls must be well reinforced, since the load on them will be quite serious, much more significant than when installing a gable roof.

• The construction of the lower rafter system begins with the installation of racks, secured with strapping at the top and at the bottom with floor beams. The distance between the rack systems will be the width of the room, and their height determines the height of the room.

Beginning of installation - installation of two rows of racks

• This frame will determine the placement of the remaining elements of the system.
• Next, you need to find the middle of the distance between the rows of racks, and this will determine location in the upper part of the attic. A vertical beam is installed in this place, the same height as the rack system.

• Then, the side rafters are installed and secured to the rack frame and beam overlap, thus creating triangles in which the stand and beam the overlaps form a right angle.
• When all side elements will be installed, proceed with the installation of floor beams, they are also attached to the strapping bar and the end side rafter. The diagram of this bundle is shown in the first figure in this section.
• Next, the floor beams are connected to each other by a horizontal rail, which is placed on top of them, in the middle of the structure.
• Installed ridge rafters, which are supported by struts. They are attached to the rail connecting the floor beams.

• On a ridge, the rafter legs can be fixed to a ridge board or connected to each other with a metal or wooden overlay
• Sometimes, for structural rigidity, a supporting headstock is installed between the ridge and the floor beam.

• The gable walls with openings for windows are lathed. If the entrance is from the street, then on one of the gables, in addition, there will be an opening for a door.

• Further, if necessary, the entire rafter system is sheathed with sheathing or plywood if a soft roof, for example, flexible tiles, is chosen as the roofing material.

Video: example of installation of a roof truss system

It is not at all necessary to equip the rafter system Just, and you can’t cope with this work alone - you will need at least two assistants. It is desirable that at least one of the invited craftsmen have some experience in this field of construction.

The rafter system is the basis of the roof; the reliability and strength of the roof, its ability to withstand precipitation and wind depend on it. The design of the rafter system is determined by the shape of the roof and the layout of the house, as well as the materials used. A do-it-yourself rafter system is usually made of wood, but other materials can also be used, for example, a metal profile.

Types of rafters and their application

Choosing a rafter system is a crucial step that requires knowledge of the design of each type of roof. Rafters can be:

1. Layered rafters supported by a ridge girder and a mauerlat. They are used in the construction of a single-pitch roof, a simple gable roof, and also as one of the elements of a hip and sloping roof. mansard roof.
2. Sliding rafters are a type of layered rafters used for wooden buildings, giving greater shrinkage. Their difference is the sliding fastening of the rafters to the Mauerlat, which makes it possible to compensate for the shrinkage of the walls without deforming the roof.
3. Hanging rafters - a system of rafters tied together with crossbars or tie rods, usually used in the construction of a simple gable roof, and also as upper rafters mansard roof. In a hanging rafter system, there is no ridge purlin, and in the upper part the symmetrical rafter legs rest directly on each other.
4. Sloping rafters, otherwise called corner or diagonal. Used to perform three-slope or hipped roof, as well as for roofs with complex geometry.

Elements of the rafter system

Any rafters are designed to distribute and transfer the roof load to the walls of the house. The main elements on which the rafters rest are:

• Mauerlat is a beam fixed to the upper plane of the walls along the perimeter of the entire house;
• Bedding - support beams laid on internal load-bearing partitions or columns;
• Floor beams of the upper floor;
• Racks and supports;
• Purlins are horizontal supporting elements laid along the axis of the roof on racks.

The roof truss consists of the following elements:

• Rafter legs - boards or timber that form the contour of the roof and are laid at a certain pitch;
• Tightenings or crossbars are horizontal elements that tighten paired rafter legs together;
• Struts - supports placed at an angle and supporting the rafter legs;
• Fillers are boards attached to the lower end of the rafters and forming roof overhangs;

Rafts are short rafters resting on diagonal rafters in a hip roof.

All these elements in private construction are usually made of wood - timber or naturally dried softwood boards. The wood is impregnated with an antiseptic, which extends its service life. The thickness and cross-section of the elements is determined by calculation.

Technology for making layered rafters

1. Before construction begins, it is necessary to sketch the roof and calculate its dimensions. The cross-section and pitch of the rafters, as well as the need to install additional supports and struts, are also determined by calculation.
2. Supporting elements are laid and positioned: mauerlat, floor beams and beams, racks, ridge and intermediate purlins. These operations are described in detail in articles dedicated to various types roofs:
3. Make a rafter template. To do this, take a board with a width corresponding effective length rafters, with the same width, but with less thickness - it is lighter and easier to precisely adjust to the location. The board is applied to the installation site of the outer rafter with one end to the ridge girder and the other to the mauerlat.
4. At the top of the template, mark the top notch. The shape of the cut should be such that the board rests on the ridge girder and at the same time fits tightly to the opposite rafter. The depth of the cut should be no more than 1/3 of the width of the board.
5. After cutting out the top cut, the template is once again applied in place and the bottom cut is marked - it should rest on the Mauerlat without leaving large gaps. The end of the template is filed at an angle so that the cut is in a vertical plane.

   

6. The resulting template is applied to the installation site of all rafter legs, checking whether adjustment will be necessary in place. If the template fits perfectly (which rarely happens), you can immediately make the required number of rafter legs. If adjustments to the bottom cut are needed, then only the upper part of each rafter is cut out using templates, and the bottom cut is made in place each time.
7. The rafters are placed with established calculation step. Typically it ranges from 50 to 120 cm and depends on the type of roofing covering, namely its severity, and the expected snow load. The heaviest coverings are slate and ceramic tiles, but they are currently rarely used. More often, the choice is made in favor of more modern, lightweight and reliable materials: metal tiles, ondulin, soft roof. For them, the rafter pitch can be chosen to be about 100 cm without performing complex calculations.
8. First, install the rafters on the gable side. Rafter leg rest on the ridge girder and the mauerlat and fasten it to two 100-150 mm nails in each fastening point. Having installed rafter pair, they additionally fasten it: in the upper part with the help of metal plates and screws on one side and corners with a stiffener on the other, in the lower part with staples or also on the corners.

   

9. After installing the rafters from both gables of the roof, string is pulled between them and the remaining rafters are aligned along it. The rafters are fastened in the same way.

   

10. Install struts if the calculation results require it. The struts are made of the same material as the rafters. Apply a board of suitable length at the desired angle to the rafters and mark the bottom cut. It is important to consider what the strut will rest on: the floor beam or the beam; the shape of the bottom cut depends on this. After completing the bottom cut, the strut is placed in place and the cutting line along the rafters is marked. The prepared strut is placed between the beams and rafters and secured with metal plates or corners.

Installation of roof struts

Technology for making hip diagonal rafters

1. Since the rafters are for hip roof install diagonally usual ways their fastenings are not suitable. In addition, the load on diagonal rafters is much higher than on layered or hanging ones, so the material for their implementation must have a larger cross-section. You can use timber with a thickness of 100 mm or more, but practice shows that it is more convenient to make these rafters from two folded and fastened boards of standard thickness.
2. The upper end of the diagonal rafters rests on the racks, and the lower end on the mauerlat bars converging at right angles. They are marked in place, and their main feature is that the cuts are made not perpendicular to the plane of the board, but at an angle of 45 degrees. When making rafters from spliced ​​boards, first one side is made with oblique cuts, then the second, in a mirror image.
3. The boards are pulled together using screws, nails or studs. The hip rafters are secured using overlays and self-tapping screws.

The video will help you better understand the basic techniques for constructing a rafter system with your own hands.

When making any rafter system with your own hands, it is important to carefully secure all components and connections and remember that the roof is the main protection of your home from bad weather. Therefore, it is important not only to make a high-quality frame, but also to choose a suitable one, for example, corrugated board, and lay it correctly.

For a good roof, it is very important that every step in its creation goes perfectly. The basis of the entire roof structure is the rafter system, the configuration of which determines the type of upper part of the building. Exist different types such systems, among which you need to choose the most suitable one for yourself, because the functionality and quality of the entire roof depends on the correctness of your choice.

Types of rafter system

The construction of the roof during the construction of a building is of significant importance. And in order for the roof to be strong enough, special attention is paid to load-bearing systems, which are divided into:

• combined;
• hanging;
• layered.

The roof is a rather complex structure consisting of various parts. The main requirement for a roof is - This is the ability to protect a structure from all kinds of weather conditions and withstand different loads.

The main loads of the roof fall on the rafter system, so it is very important to choose necessary materials, calculate everything correctly and install it in accordance with the technology.

Installation of hanging rafters

Hanging rafters are intended for buildings in which there are no permanent partitions inside, and the distance between the common load-bearing and side walls is no more than 10 meters. The roof structure in this option rests on the main walls of the building, but because of this it is subject to high loads. To make the voltage a little weaker, use additional details(bolts or crossbars) that secure the truss in a horizontal position.

Depending on the span length, various reinforcing elements are used in the construction of hanging rafters

The lower ties are connected at the base of the rafters and can be used as beams for the attic floor, but they must be laid on the mauerlat. To make hanging rafters, a board with a cross-section of 50x200 mm is usually taken, but each individual building needs its own specific calculations.

Sequence of actions for installing hanging rafters:

Installation of layered rafters

Layered rafters are mainly installed in those buildings where there are load-bearing partitions. They are much easier to install than a hanging system, since strong load-bearing walls located inside the house provide reliable support for the rafters. In addition, this system requires a minimum amount of building materials.

The ridge board in this case serves as a reference point. Such roofing system installed in one of three options:

To secure the rafters at the bottom of the roof, it is necessary to use sliding fasteners, which relieve the load-bearing partitions from additional stress. In this case, the rafters are not fixed very tightly, so that when the building shrinks, they can move without overloading the roof structure.

But in some cases, you can use a spacer system that is tightly attached to the Mauerlat below. Struts and ties are installed in the structure to reduce the load on the walls. This method is called complex because it combines elements of two systems.

This roofing system is used mainly for the construction of private buildings, so it is worth mentioning the installation work, which is carried out in the following sequence:

Installation work Installation of a layered system should begin with laying boards on the floor beams. This device will help you carry out work comfortably and safely.

Combined roofing system

Combined rafters have elements from layered and hanging systems in their design. They are used in the manufacture mansard roof. The walls of the rooms on the second floor are made up of vertical posts, which act as a fulcrum for the rafter beams.

Horizontal bars, which were installed on top of the racks, perform two functions: for the upper slopes they are the Mauerlat, and for the side ones - ridge beam. Some part of the rafter system, which is connected at the top of the ends of the racks, simultaneously becomes a tightening for the upper elements and a crossbar for the slopes located on the sides.

The combined roof uses fragments of layered and hanging rafter systems

To increase the strength of the structure, it is necessary to install struts that secure the rafters and vertical racks roofs. Making combined rafters is a little more difficult than other systems, but the labor intensity of the work is offset by an increase in the load-bearing characteristics of the roof and the presence of a full-fledged room under the roof.

Photo gallery: options for rafter systems

In the design of a hip roof, layered rafters are used. For an envelope roof, a rafter system is erected, similar to the attic. broken roofs at the joints there are special rafters that support the valleys. Multi-gable roofs consist of several different rafter systems combined into one. In the rafter system of an attic roof, the same element can be both a mauerlat and a ridge

Installation of roof truss system

The rafter system is made of coniferous wood. You can use boards or timber that are treated with antiseptic substances before installation. Fasteners can be as follows:

• wooden scarves;
• metal plates;
• various cuts;
• nails.

When starting to install the rafters, the level of the floors and load-bearing walls is raised, after which waterproofing is laid. The rafter structure is necessary to prevent deformation of the rafters. The supporting elements that give the rafter system stability can be:

• sunbeds;
• struts;
• runs;
• racks.

Insulation of the roof is necessary, but for this you should choose a material for hydro-, heat- and vapor barrier. Installation is carried out layer by layer and only in the sequence in which it is necessary: ​​initially steam-, then heat- and finally moisture-proofing material.

Before laying the roofing covering, the necessary protective materials in compliance with the established ventilation gaps

To ensure long-term operation of the rafter system, the necessary air circulation is arranged by installing ventilation holes. To prevent leaks, “collars” are made near the holes to prevent water from penetrating under the roof.

Video: DIY rafter system installation

How is the Mauerlat attached?

The Mauerlat is the foundation of the roof, so you should treat it responsibly. Otherwise, roof repairs will be inevitable in the future. Sequence of work:

Methods of fastening roofing Mauerlat and splicing rafters

The Mauerlat is attached to the walls of the building along the entire perimeter, and the fastenings must be located in close proximity to the inside of the wall. Outside the house wooden detail protected by a slight projection of the wall. The mounting location is also initially determined.

How to fix the Mauerlat to the wall

The Mauerlat can be attached to the wall in the following ways:

How to fasten rafters to the Mauerlat

All options for attaching the roof rafter system to the Mauerlat can be divided into the following types:

How the rafters are attached at the ridge level

The most common option for attaching rafters to the ridge is a butt connection:

Rafter splicing options

IN construction industry used everywhere various options rafter splicing, while selecting a certain technology, you need to pay attention to the design characteristics of the rafter system, which are influenced by:

• purchased materials;
• technical data of the construction site;
• rafter installation step.

Rafters can be spliced ​​as follows:

Each type of rafter system has its own characteristics and is only suitable for a certain type roof structures. Exactly from correct installation rafters depend not only on the reliability, but also on the strength of the roof, so this stage of work must be approached with maximum responsibility.

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