How to make a rafter system. Installing rafters yourself - expert recommendations Aligning rafters

Installation and installation of a roof is a complex and responsible matter. The main element of the roof is the rafters. Figuratively speaking, this is the skeleton of the future roof or frame. You can make it yourself, while following strict rules. A poorly made rafter base will lead to many problems.

Types of roofs

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

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

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

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

What you need to know when installing rafters

Rafters are a load-bearing structure. It must reliably hold the entire weight of the roofing material, resist gusts of wind and withstand snow loads. In this regard, when choosing a material for making rafters, you need to take into account the above factors, as well as the climate in the area where construction is taking place. The main elements of the rafter system are the beams, the rafters themselves, and the mauerlat.

Kinds

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

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

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

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

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

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

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

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

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

Lathing with gaps is used to cover roofs using asbestos-cement slabs. When using slate, tiles or fiberglass, the sheathing is made from beams that have cross-section dimensions of 50x50 mm.

Installation technology

It is as follows:

Only high-quality wood is used for the manufacture of rafters, without external defects or damage. This is, as a rule, lumber of the first or, less often, second grade.
Rafters are produced using a circular saw, which performs cross cutting. Trimming is performed using special templates. Longitudinal cutting is also performed on the same machine.
In order for the integral structure to be assembled in the correct order, it must be produced according to a previously planned scheme.
After the preliminary work has been completed, the rafters must be numbered to avoid errors during the subsequent cycle of work.
Then sockets are selected for installing bolts and dowels.

Rafters can be purchased ready-made. Some construction organizations are engaged in this work. If material resources allow, it is better to use a factory design.

The most popular and stable version of the rafter structure requires the following requirements:

The basis of the structure is a beam, which consists of several beams connected to each other using plate dowels.
dowels are made only from oak or birch;
dowels are attached only to the outer parts, and in no case to the middle;
the wood must be dry, with a permissible moisture content of no more than twenty percent.

Installation

First you need to calculate the weight of the roof. If you plan to build a roof of a lightweight structure, then you don’t need to use a Mauerlat. It is designed to uniformly distribute the concentrated load, which is transmitted by the support points of the rafters to the outer area of the outer wall. But they perform another important function - they tie the roof to the walls of the house. This is especially true in areas where winds constantly blow. They are square beams measuring 15x15 cm in cross section. They are directly laid on the surface of the walls.

The rafters are also wooden beams, but of a different section. Their thickness is 5 or 7, and their width is 15 cm. If you are planning a roof made of heavy material, then the rafters must be chosen larger: 8x20 cm. The distance between adjacent rafters is called a pitch. Depending on the chosen system, the step can be from half a meter to one meter.

Before starting work on the installation of rafters, it is necessary to make scaffolding. Using a ladder for these purposes is neither effective nor very convenient. The most convenient option for joining rafters is when this process is carried out on the ground. Then the finished structure rises to the top. There are only three mounting methods:

The connection is made end-to-end, the rafters are fastened with two 200 nails. To further strengthen the connection, you can use a wooden overlay or a metal plate. They are fastened with self-tapping screws or bolts.
Using ridge beams. In this case, each of the rafters is attached separately, without the use of templates.
The joining is done with an overlap. For this purpose, special studs with wide washers and iron bolts are used. The last method is the most common.

The first step is to install the outer rafters. A measuring rope is stretched between them, which will make the roof level. Then, with a certain step, intermediate rafter triangles are installed.

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

Note! There are several options for fastening rafters, which can be used depending on the structure of the building and the features of the roof. If the house is made of stone, then the rafters can be secured with wire to the reinforcement driven into the wall.

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

Video

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

Practical issues of rafter installation are discussed here:

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 a simple design that is difficult to spoil. Fifth - she looks attractive. All this, and the fact that a gable roof is built with your own hands without special knowledge, determines its popularity.

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

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 the order is the 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.

Using raw wood with natural moisture when building a roof 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 kiln 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 then use it in the installation of the 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

The assembly of the gable roof rafter system begins with the installation of 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 with 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, a reinforced reinforced concrete belt is made on top of the last row of masonry, 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:

A smooth rolled wire of large diameter (two ends sticking up) is fixed in the masonry (in a reinforced concrete belt). Holes are then made in the board in the required places into 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 timber or board along the outer or inner edge of the wall, take a drill with a diameter of 12 mm and make holes for the 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 inclined boards, one end of which rests on 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 gable roof is assembled with your own hands and is ready for installation of 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

The difference between 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 that 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.

While building your house, you will definitely encounter many difficulties. First you need to draw up a project, then prepare the material, and then begin building the structure. Each stage has its own characteristics and difficulties; if you do not get acquainted with them in advance, then construction can easily be delayed. For example, installation of a rafter system. The durability of the entire house depends on the correct execution of this stage. How to do it correctly?

First, about the design itself

Installation of the rafter system is carried out in a certain sequence. To know how to do the work, you must first become familiar with the structure itself. The roof truss system consists of the following main elements:

The lowest “tier” of the rafter system is the mauerlat. It is a wooden beam located around the entire perimeter of the building. Mauerlat serves two purposes. Firstly, it evenly distributes the load from the rafter system onto the walls of the house. Secondly, the Mauerlat allows you to align the base horizontally;
Rafter pairs are the main element of the entire system. It is he who takes on all the loads and also connects other components;
Run. It is a wooden beam. Most often it is installed up at the ridge and connects the rafters. Also, in some cases, the purlin is installed from below. In this case, it serves as an additional fastening element for the rafter legs;
Puff. It is required to be used in. The tightening fastens the lower ends of each pair together. In some cases, the element may be located in the upper part of the rafter triangle;
Struts, racks. The elements serve as additional support for the rafter legs;
Filly. Additional element. Installation of the filly is necessary in order for the overhang.

The rafter system has both mandatory and optional components. For example, Mauerlat. It is used almost always, with the exception of houses made of wooden beams. Here you can do without an element. In this case, the role of the Mauerlat will be played by the upper beam.

Some experts also include sheathing in the rafter system. This structure serves as a support for the roofing material. In some cases, a continuous sheathing is required, and in others, a thin sheathing is required. The first option is used for soft roofing.

Types of system

Rafters are the basis of the entire roof structure. They are the ones who take on all the loads and transfer them to the walls. If we are talking about a gable roof, and this is the option that is used most often, then the rafter system itself can be made in two main versions:

. Such rafter systems are used in cases where the house has a small width. The span length should not exceed six meters. The hanging system involves the support of the rafters only on the mauerlat or directly on the walls. From above, the pairs are simply connected to each other; there is no ridge run. From below, the rafters are additionally attached to each other, in pairs, by guy wires;
. This rafter system is used if a load-bearing wall or column runs through the middle of the house. They serve as a support for installing the ridge girder. The layered rafter system is used in the construction of wide houses.

A combined option is often used. For example, it is used in the construction of a gable roof. In this case, extensions extend from the main building at right angles. The main house is covered with a roof using a layered rafter system. Side extensions, since they are usually not wide, can be “covered” with a hanging structure.

Installation procedure

Correct installation of the rafter system is carried out in a certain sequence. A lot depends on the characteristics and type of roof. The simplest option is a flat roof. In this case, no special skills are required. It is enough just to lay the beams, creating the necessary slope, and install the sheathing and roofing materials on them.

The second most difficult is considered to be a gable roof. This is exactly what we will talk about. Knowing the sequence in the case of a gable roof, you can easily navigate other options.

The sequence of actions when installing the rafter system is as follows:

At the end of the installation of the rafter system, the sheathing is installed. Waterproofing material must first be laid. If this is not done, the wooden elements will get wet and quickly fail.

There are some features of installing a rafter system on a house built of wood. Firstly, in this case the Mauerlat is not used. Secondly, the rafters themselves are necessarily attached to the upper crown of the walls using a sliding method. This is necessary due to the nature of wood. It begins to dry out over time. If the rafters are fixed in a rigid way, then the entire system will definitely fail and the roof will simply collapse.

Features of installation of different types of roofs

There are a lot of roofing options. Each owner chooses according to his preferences and tastes, and the features of the house itself are also taken into account. Depending on the type of roof, the installation of the rafter system is carried out with some differences, namely:

You can build a gable and single-pitched roof yourself. To install a rafter system, you need some carpentry skills and clear calculations and planning of your actions. All calculations can be easily done using special programs on the Internet. There you can also find installation instructions.

For other roofing options, quite a lot of experience is required. That is why their construction is most often trusted to professionals. Of course, in this case the cost of the roof will increase significantly. But you will have a guarantee that everything is done correctly. This means that the house will be reliably protected from external influences and will last for decades.

21.02.2017 1 Comment

The rafter system of a gable roof is a simple design that can be installed with your own hands even by a novice developer. You just need to make preliminary calculations, familiarize yourself with the details and stages of roof construction, and calculate the materials needed for installation. When making calculations, it should be taken into account that the load-bearing capacity of a gable roof depends on the influence of loads from wind, snow, and the weight of materials on it.

To make the process of building a gable roof rafter system as easy as possible for you, below is detailed step-by-step instructions for installing a rafter system with your own hands.

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Requirements for building materials

For the installation of a rafter system, the best option would be to use lumber from coniferous wood - pine, spruce or larch, grades I - III.

The material for the rafters is taken at least grade II, the mauerlat is made from boards or timber of grade II, material of grade II is taken for racks and purlins, the sheathing is made from lumber of grades II-III, it depends on the roof. Crossbars and tie-downs are made of Grade I material. Grade III material can be used on linings and linings.

Note! The lumber must be dry with a moisture content of no more than 20%. Before installation, it should be treated with fire retardants and antiseptics against fungal diseases.

Lumber should be stored under a canopy, providing protection from the sun and moisture. Level the storage area and cover the lumber with pads for ventilation.

For installation you will need fastening elements: ties, plates, studs, bolts with washers and nuts, self-tapping screws with EPDM gaskets, 2.8 mm thick, mounting tape, galvanized brackets.

Brackets are used when attaching the Mauerlat; they are secured with nails or self-tapping screws.

KR corners serve to attach the rafters to the mauerlat and prevent the rafters from moving.

All fastening material must be made of high quality material and be protected against corrosion.

Tools for constructing a rafter system

To install a gable roof rafter system, you will need the following set of tools:

tape measures of different lengths 5, 10, 20 meters;
markers, pencils;
cord for tensioning;
hammers, for various purposes, nail puller;
scissors, for cutting;
roofing knife;
putty knife;
scotch;
hacksaws, electric saw, electric drill with various drills and attachments;
screwdriver with attachments;
markings, horizontal and vertical levels;
slats, rulers;
polyurethane foam;
safety belt and rope - for safe work.

Keep all tools on the roof in a tool bag for safety reasons.

Types of rafter systems for a gable roof

Sent rafters

They rest on the mauerlat and racks installed on the internal wall, with a pitch equal to the rafters. To provide rigidity for spans of 6 m, additional struts are installed.

Scheme of layered rafters of a gable roof

Hanging rafters

If the building is small in width, you can arrange a rafter system where the rafters rest on the mauerlat or walls, without intermediate supports. The maximum span is 9 meters. Such roofs can sometimes be installed without a Mauerlat. The rafters are installed on the wall using spacers; in this embodiment, a bending moment acts on the rafters.

To unload, wooden or metal plates are installed. They securely strengthen the corner. For hanging rafters of a larger span, a headstock and struts are installed. For hanging systems, the rafters are made with a larger cross-section, and lumber is chosen at least grade I II.

Scheme of hanging rafters of a gable roof

Calculation of the rafter system

You can determine the cross-section of a gable roof beam required in a rafter system by collecting all the loads acting on it: the weight of the covering, sheathing, snow, wind pressure, precipitation.

Constant loads can be determined by the weight of 1 m 2 of roofing and sheathing. It is important that the weight per 1 m 2 of roofing be in the range of 40-45 kg.

Variable loads from snow and wind are calculated using tabular values of SNiP normative documents, depending on the height of the building and temperature zone. The load from snow is equal to its weight multiplied by a coefficient depending on the slope of the slope. All these calculations are performed during the project.

What if there is no project and the roof is being erected on a small building? You need to look at the construction of a house in the neighborhood, which is being carried out according to a design whose roof area is the same as your building. The gable roof rafter system will serve as a model.

Dimensions of timber for rafters

At the top point a ridge is laid that connects the rafters. The height of the ridge depends on the slope of the roof. The slope is affected by the choice of coating material. The minimum sizes are:

for tiled roofs, slate 22 gr.;
for metal tiles - 14 g;
ondulin - 6 g;
corrugated sheeting - 12 gr.

The optimal angle is 35-45 degrees. tilt, ensures rapid discharge of water and snow. In regions with strong winds, the roofs are made flat and then the angle of inclination is within 20-45 degrees.

The height can be determined using the formula: H=1/2Lpr*tgA. Where A is the angle of inclination, L is the width of the building.

The task is simplified when using a ready-made table. The coefficient depends on the width of the building and the angle of inclination. Multiply the coefficient by 1⁄2 the width of the building.

The rafters are made from pine or spruce bars, with a section of 50x100 mm, 50x150 mm.

The size of the rafters depends on the pitch. The pitch of the rafters is smaller, a larger number is installed, and the cross-section will decrease. The distance between the rafters on a gable roof ranges from 600 mm to 1800 mm, it all depends on the design of the roof and the materials used for its construction.

Table of rafter sizes, depending on the step of their installation

Length rafters, mm	Distance between rafters, mm	Rafter beam cross-section size, mm
up to 3000	1200	80×100
up to 3000	1800	90×100
up to 4000	1000	80×160
up to 4000	1400	80×180
up to 4000	1800	90×180
up to 6000	1000	80×200
up to 6000	1400	100×200

The roof does not end at the level of the walls; it is extended outward by 500 mm. The rafter leg can protrude, or a board or block can be built up. In this case, moisture does not get on the wall and the foundation is not poured.

Step-by-step installation of a gable roof truss system

The rafter system of a gable roof consists of the following elements:

Mauerlat.
Lay down.
Racks.
Rafters.
Struts.
Puffs.
Lathing.

Mauerlat installation

Fastening the Mauerlat to a monolithic reinforced concrete belt

Mauerlat evenly distributes the load on the walls of the building; its installation can be done in several ways:

attached to the wall through a reinforced concrete belt with studs;
studs are inserted into the masonry;
a simple and common method for simple roofs, fastening with wire rod.

For it, take timber with a cross section of 100×100 mm, 150×150 mm or 200×200 mm. Which section to choose depends on the size of the roof and its covering. The Mauerlat is joined along its length; to do this, make 100 mm cuts, 500 mm long, fold the bars and fasten them with pins.

In the corners, the mauerlat is tied with notches into the floor of the timber, fastened with staples or bolts. For wooden buildings, the Mauerlat is the last crown. On brick walls, make a monolithic reinforced concrete belt with a cross-section of 400×300 mm. Along the belt, place threaded pins 12 mm in diameter, every 120 mm, for fastening.

Drill holes with a diameter of 12 mm in the Mauerlat, lay them so that the pins go into the holes. Tighten the top with nuts. First, we lay two layers of roofing felt or roofing felt under the block. On the outside of the wall, lay the mauerlat with bricks. Lay the Mauerlat on a horizontally and vertically level base. You need to check with a level that the surface is horizontal. Check diagonals. If necessary, level with pads.

Installation instructions for beds, racks, rafters, struts and tie rods

The installation of a gable roof rafter system with your own hands is carried out in the following order:

Install the beam with the rafters in place.
Mark the installation step of the rafter legs.
Prepare according to the size of the rack.
Install them if there is a need to secure them with spacers.
Lay the purlin. Check geometry. Install fasteners.
Try on the first rafter leg and mark the cutting areas.
Mark the points and install the rafters at the beginning and end of the roof, stretch the cord between them in order to align the remaining elements along it.
Having installed the rafter leg, we first attach it to the mauerlat, then to the ridge purlin, to each other.
Screw each second leg to the mauerlat with wire.

The rafters are fastened to the mauerlat using notches, stop corners and a hemmed support bar. Secure with nails or staples.

Methods for attaching rafters to the Mauerlat

Install the support posts on the beds or pads and overlays. A log is a beam 50×100 mm or 50×150 mm, laid on the middle wall along a layer of roofing felt. Place brick pillars under the linings, 2 bricks high.

The rafter legs are connected to each other at the ridge. Let's consider the common connection nodes of the rafter system:

They make cuts at one leg and cut down at the other. Insert one leg into the cut of the other and fasten with a bolt.
Install overlays, wooden or metal.
Using notches in the purlin, they are secured with nails or bolts.

Methods for connecting rafters on a ridge

To ensure the roof's resistance to wind loads, tie-rods, struts and purlins are installed. The tightening is a 100×150 mm block, purlins and struts are made from a 50×150 mm or 100×150 mm block.

With the installation of contractions, the reliability of the rafter structure increases. The sections of the timber are the same as the rafters. They are attached to the legs with bolts or nails. The device of struts adds rigidity to the structure. They are installed tightly to the surface of the rafters

The lumber has a standard length of 6 m. The rafters can be longer. Then you need to dock them. There are several connection methods:

Fasten by placing bars on both sides at the junction, connecting them with nails in a checkerboard pattern.
Connect with an overlap, one part of the rafters to another, at a distance of 1 meter, fasten with nails in an alternating order.
Make a cut obliquely, cut out part of the rafter legs, connect them, strengthening them with bolts.

Sheathing device

Lathing is installed along the roof rafters. It serves to distribute the load from roofing material and snow onto the rafters. Plays the role of an air gap between the roof and the rafter system.

The design of the sheathing depends on the roofing material used:

under the soft tiles, make the sheathing continuous, lay an anti-condensation film on the rafters, press it on top with a counter batten, nail the sheathing onto it, then OSB boards and underlayment carpet, lay the tiles on top.
Under the roof made of corrugated sheets, the sheathing should be sparse. The pitch of the sheathing depends on the brand of corrugated sheeting, its thickness and the angle of inclination of the roof.
The lathing for standard slate should be made in increments of 500 mm from a bar of 75×75 mm or 50×50, as well as boards from 30×100 mm. The design features of the roof should be taken into account when making the final choice of the appropriate option.

The lumber from which the sheathing is made is first or second grade pine. It is advisable to take the width no more than 14 cm. With a wider width, the boards may warp and damage the roofing. The length of the nails should be three times the thickness of the sheathing. Lay the boards along the ridge. Install the first board of greater thickness to the height of the roofing.

Install continuous sheathing along the roof slope.

The first layer is to place a board along the ridge from it at a distance of 500-1000 mm to the next one and so on. Lay the second layer of sheathing along the rafters. Place the joint between the boards only on the rafters at intervals. Sink the nail, head and all, into the flesh of the wood.

Cornice overhangs

They are installed to protect against precipitation and play an aesthetic role. Eaves overhangs are arranged tightly without gaps. The final stage of installing the roof.

Diagram of the eaves overhang of a gable roof

Gable

The gable roof has two gables. They have the shape of a triangle, with the apex at the ridge and the sides coincide with the slopes of the roof. The gables support the rafters and enclose the attic space. They protect from wind and precipitation and provide stability to the roof.

In wooden buildings, the pediment is framed. In brick buildings, frame or brick. Gables made of brick or gas block are erected before the roofing is installed. They require very precise execution.

Frame pediments fit into the finished opening when the rafter system is already assembled.

The frame is made of bars or boards. The frame elements are connected on tenons or in the wood floor, all fastened with nails. They are sheathed by nailing boards, lining or siding, maintaining the color scheme in the decoration of the building facade. To construct a window opening, an additional frame is made under it according to the size of the window. If the attic is insulated, then the gable also needs to be insulated. The insulation is placed in the middle of the frame. Mineral wool insulation with reduced flammability is used. On the outside, the frame is covered with a hydro-windproof film or windproof membrane; on the inside, a vapor-proof film or a vapor-proof membrane is nailed under the finishing material.

In contact with

It is better to entrust the installation of rafters to specialists; the roof is not an element of the building with which you can experiment. However, it is necessary to know the basics and features of how to install rafters on a house, at least in order to control the quality of work and be able to build a simple rafter structure.

How to correctly install rafters on a house - let's understand the terms!

If most people have the slightest idea what rafters are, then a problem may arise with the other terms encountered in the roofer’s business. Mauerlat, crossbar, beam, stand, strut, purlin - it’s unlikely to do without the help of specialized literature or an experienced builder! However, if you are reading this article, you can do without them.

Mauerlat is traditionally a wooden beam with a cross-section of 15*15 cm, which serves as the extreme lower support for the rafters, distributing the load from the joining points of the rafters over the entire upper area of the wall. Recently, instead of wood, metal is often used; for Mauerlats these are channels and I-beams. The Mauerlat is installed with a slight indentation from the outer edge of the wall and secured. To prevent rotting and corrosion from below, the beams are insulated with roofing felt or other waterproof material. It is from this element that the installation of rafters often begins.
Lezhen is an additional beam for distributing the load from the rafters along the entire perimeter of the walls. They differ from Mauerlats in that the beams are installed inside complex rafter structures, that is, they are not a mandatory element of the roof, but only an addition in the necessary cases.
A stand is a vertical beam that strengthens the rafter structure from the inside. Purlins are in turn installed on the racks, which are supported by struts - inclined beams that support horizontal elements and resist compression or distortion of the structure.
A purlin is a horizontal beam that crosses the rafters perpendicularly along the entire length of the roof. In the roof structure, three types of purlins can be distinguished - ridge purlins (on which the rafters meet at the top of the roof), side purlins and mauerlats, which are described above.
A crossbar is a beam that is installed between the rafter legs, increasing the strength of the structure and its stability. Typically, the cross-section of the crossbars is 10*15 cm.
Rafters or rafters are beams on which the roofing covering is directly installed. Rafters are also a general name for the entire rafter structure. For this element, a beam with a cross-section of 10*15 cm is used. For the manufacture of a plank rafter system, a pine board with a cross-section of 50*150 mm or 60*200 mm is used.

Before installing the elements, it is necessary to accurately calculate their number, and also take into account the possible loads on the rafters: they can be one when installing slate, another for tiles and a third for.

For example, a pitched roof, built from a minimum number of elements, can easily support sheets of metal or slate, while under the tiles, over time, the rafters can become deformed and bend, which means you will need to additionally strengthen the structure with racks or struts, and also use beams with a large cross-section .

How to install rafters correctly - layered or hanging?

Rafter structures are divided into two groups - layered and hanging. Hanging rafters are usually constructed on the roofs of buildings without internal load-bearing walls. The hanging structure rests on the ridge girder and mauerlats, and is fastened at the bottom with ties that prevent the rafters from moving apart under load. It should be noted that much more timber is used for hanging rafters, since this ensures their stability. You can save wood on plank rafters, since log options require 15-20% more timber.

Layered rafters are installed on those buildings that have load-bearing walls inside, since this type requires a minimum of three support points. Layered elements can be used to cover spans up to a maximum length of 6.5 meters. If there is a need to increase the width of the area to be covered, then this can be easily achieved by installing additional supports: with one additional riser, the width can be increased to 12 meters, and with two – up to 15!

Depending on the cross-section of the beams that are used to make rafter legs, the spacing of the rafters varies from 0.8 to 1.2 m. The lower ends in the layered type of rafter structure rest against the mauerlats, and the upper ends against the purlins. The construction of a rafter frame, including purlins, racks and struts, ensures special stability of the rafter legs. This type is most often used in private construction, since on the one hand, you get a strong and reliable roof, and on the other hand, layered rafters are very economical– wood on them, compared to hanging ones, is needed several times less. Quite often, roofing is constructed by combining both types.

How to install rafters on the roof - what for what?

To begin with, following detailed instructions like those given in a separate article, calculate how much material you need. Before installing elements of the rafter structure, they must be treated with compounds against fungi, insects and fire retardants that prevent ignition. By investing in these compounds before placing rafters on the roof, you will extend their service life by decades.

How to install rafters on the roof - step-by-step diagram

Step 1: Installation of Mauerlats

The most important connection in layered versions is considered to be the place where the rafter leg rests on the mauerlat. It is with securing the Mauerlat that the installation begins. To do this, metal pins are pre-concreted in the walls, which go at least 40 cm deep into the walls. Twisted wires with a diameter of at least 6 mm will also be suitable for the same purposes.

Step 2: Making a Layout

Lift up two beams that will serve as rafter legs. Cut out notches on the left and right legs to support the mauerlats, do not forget to mark for yourself which side belongs to which beam. Install the beams, connecting them at the top to make marks for the notches at the top. The notches are needed in order to make a connection with a stop, and not an overlap - this is considered extremely unreliable even with strong reinforcement with nails.