How to make a rafter system with your own hands. Device and step-by-step installation of the rafter system Side rafters

Ideally, the installation of the roof should be entrusted to professionals, if you decide to do the work yourself, then there must necessarily be at least one person who is familiar with this business firsthand. Also, you should not immediately proceed to complex forms of construction, no matter how attractive it may seem to you. It is better to try your hand at installing simple gable roofs, with a minimum number of valleys and complex elements, because even the masters do not always succeed in their business.

Tools for installing the rafter system

First of all, for high-quality work, you need to stock up on the necessary tools. It does not have to be professional, but the convenience and speed of installation will depend on the completeness of the set. For the device of the rafter system, you will need:

Hammers, different types and weights;

Nail puller;

Pencil, marker for marking;

Center punch, with which it is very easy to punch points for drilling technical holes;

• Hacksaw or chainsaw for woodworking (sawing workpieces to size, at a certain angle and technological notches);

  Tape measure, for accuracy of measurement, its value should be not less than the size of the longest element of the roof, rafter leg or ridge girder;

  Drill with a set of drills and a countersink;

  Bulgarian;

  Level, plumb;

Also, for the convenience of installation, other devices are used that are made independently, these are "thorns", templates, etc. The "thorn" (Fig. 1) is used as a stop when the rafter sector is installed in a vertical position. It is a piece of timber with a section of 6x6 cm, on both sides of which a metal corner of 40x40 mm is nailed. It is cut in such a way that, as a result, two sharp ends are formed, with their help, a safe lifting of the structure is ensured and all kinds of sliding are excluded.

Another mechanism that can come in handy when installing rafters is insurance (Fig. 2). It is easy to build it from a cable hoist and a hoist. With the help of a simple device, you can adjust the length of the outlet and prevent the structure from tipping over in the opposite direction. The length of the safety rope must be checked in advance before lifting.

Templates (fig. 3) serve as an auxiliary measuring tool. By means of them, the corners are beaten off, the rafter sections are assembled on the ground and the distance between the frame elements is controlled.

Rice. Fig. 1 2

The procurement of structural details is impressive, rafter boards are required

The installation of rafters begins with a study of the drawings and a selection of the main dimensions of rafter legs, girders and other details, this is required in order for the manufacture of blanks, cutting lumber to be rational and economical. In some cases, when the overall dimensions of the house are lengthened. Not only must the joints be strong and reliable, the recommended location of the joint is at least 1 m from either edge of the rafter and no more than 1/3 of its length. It is not advisable to do it in the middle, from two equal parts, this reduces the bearing capacity of the elements.

You can lengthen the boards by overlapping and through the overlays. In the first case, technical holes for bolts are made on the docking board, the recommended location: the initial holes are drilled 50 - 100 mm from the end of the workpiece, this will prevent wood warping. The rest are drilled in a checkerboard pattern at a distance of 80 - 100 mm from each other, this will exclude the appearance of cracks.

In the second option, to lengthen the workpiece, wooden pads are used, which are nailed on both sides of the joint of two parts, thereby providing a rigid connection.

We also prepare in advance struts, crossbars, purlins and other details according to the project documentation. In order to eliminate miscalculations, you need to measure the size of the elements with a small margin, which can be easily adjusted in place. There is one more thing worth knowing. Before starting the installation, you need to carefully measure the geometry of the Mauerlat (support bar). For this, the length, width, rectangularity of the corners, the difference in diagonals are checked, the last parameter should not exceed 20 mm. The level breaks through the flatness of the base. If all values ​​are within the permissible range, then you can safely stamp all sections of the rafters according to a single template, otherwise, you will have to adjust each element individually.

Assembly and installation of the truss structure

Initially, you need to decide on the place of assembly of the rafter segments. It can be produced on the ground, but in this case the whole structure will have to be understood upward as a whole, which is not very convenient and expedient. Assembling the rafters in place is considered a good option; it is possible when the floor surface allows it. All elements are lifted separately, which is much easier and easier.

When assembling, we lay out all the parts as they should be, and fit each other (Fig. 4). In the upper part of the rafters, we fasten the planks with a nail fight, and then additionally fasten the legs with small crossbars. At least five nails are stuffed into each connection. In the lower part, where the legs rest on the tightening, we fasten the temporary bars (Fig. 5) so that when lifting the leg does not slip off the tightening. But the supporting elements of the structure are connected with permanent bolted fasteners with metal strips on both sides.

An inch board is often used as crossbars, it is sewn with nails on both sides of the structure. After the assembly of one section is completed, the structure is set in a vertical position.

To simplify the lifting process, it is divided into several stages. At the beginning, the rafters are raised to an angle of 25 - 300, in order to make it convenient to nail the upper cross member on the other side of the assembly. At the second stage of lifting, the structure is lifted by means of a belay and is fixed with a "thorn" at an angle of 55 - 600, in this position the second crossbar is nailed, just like the first one earlier (Fig. 6). At the final stage, the rafter section is installed in a vertical position, the reference point for the correct position is the plumb line attached to the crossbar. When the structure is vertical, we fix the assembly with a board. The sequence of subsequent actions has several variations.

In one case, two rafter sections are placed at the ends of the building, a cord is pulled between them, and the entire structure is already assembled along it.

At the same time, auxiliary elements, various supports, linings are very actively used, which help to fix individual parts of the rafter system in the desired position. Temporary structures are not removed until the final installation has been completed.

The installation of rafters can be in a different scenario, it is more suitable for those who decide to assemble sections in place. The main difficulty is that as the roof is erected, the space for connecting elements very quickly decreases. But this problem also has its own solution. At the beginning, rafters are installed over half of the house, five to ten pieces, depending on the size of the roof.

We collect the second half of the total number of rafters and lean against the already mounted ones (Fig. 7). Then the extreme section is exposed on the opposite side, and then we move apart and install the rest of the rafter assemblies. Moving them is not particularly difficult, since when tilted, they hang on the upper run and have no opportunity to fall. This option for installing the rafter system has become very popular among developers. It impresses with its simplicity and ease of implementation of many projects.

It is worth focusing on one more detail, since the structures are mainly made of lumber, it is necessary to take into account the fact that the tree shrinks over time. Therefore, it is strongly recommended that a sliding fastening element is used in the intermediate part of the rafter support (Fig. 8), among themselves the builders call it "sliding". "Slider" is installed strictly perpendicular to the rafter. Initially, the element is installed in the most extreme position, so that during the shrinkage of the house, the rafters have free play.

Upon completion of the installation of the rafter system, they proceed to the next stage - the sheathing of the structure.

The service life of a house directly depends on how well all parts of its structure are made. And the roof is no exception here, because it is she who protects the floors from precipitation and sunlight. In addition, the roof allows excess moisture to be transported away from the walls of the building. If you decide to make rafters with your own hands, you need to familiarize yourself with the features of their construction.

Many types of roofs are known today. Despite the variety of design features, all of them are attached to the frame of the house using rafters - wooden beams that can be installed either directly or at a certain angle to the walls. Subsequently, wooden elements are mounted on the beams, on which, in turn, the roof is laid. Before making the rafters, you need to familiarize yourself with the basic design features of different types of roofs.

Types of roofs and features of their construction

The easiest to arrange with your own hands are single-pitched or gable roofs. They are most often used in the construction of country houses. At the same time, single-slope structures are mainly erected during the arrangement of outbuildings: sheds, temporary huts and other utility rooms. In the construction of residential buildings, sloped or gable roofs are used.

There are also the following types of roof structures:

• hip;
• tent (hipped);
• cross.

These types of roofs consist of complex structural elements, so if you need to make them, it is better to seek help from specialists.

If we talk about rafters, then they are also divided into two types and can be layered or hanging. Hanging rafters are usually supported by the external or internal walls of the building. The upper end of the beams are attached to the ridge girder. The lower parts of the beams abut against the extreme supports, which are the walls of the house.

When installing hanging rafters, it must be remembered that this type of structure does not have an internal pivot point. Improper installation can cause the roof elements to press too high against each other, which can cause the walls to topple over or collapse.

To prevent this from happening, all elements of such a structure must be firmly connected to each other. To do this, a tightening belt is arranged in the lower part of the rafter system, which makes it possible to exclude the strut of the construction truss. The assembly of the hanging truss structure can be done both on the house and on the ground. In the second case, in order to raise the roof onto the building, a truck crane will be required.

Unlike a hanging structure, layered rafters are attached not only to the ridge girder, but also to the internal support, which makes the construction process of this system quite simple and does not require the use of special mechanisms and equipment.

Materials required for equipping the truss structure

Before making rafters for a gable roof, you should decide what materials will be used for their manufacture.

Here it is also necessary to focus on the recommendations of experienced builders. For example, many craftsmen do not recommend using logs for beams, due to their high weight. In addition, it is advisable to use self-tapping screws as a fastening material, not nails. And in fact, and in another case, you will need to use pads and liners.

The amount of materials that are needed in order to make the rafters for the roof also depends on the assembly option of the rafter structure. Today there are several of them:

• using racks;
• using struts;
• using both racks and struts.

Taking into account all of the above factors, the following materials and tools will be required to equip the structure:

• boards or beams made of coniferous wood with a thickness of 40 to 100 mm;
• a beam with a section of 10x10 cm for the ridge of the roof and the manufacture of a lath and a Mauerlat;
• steel strip clamps;
• nails or screws;
• staples;
• axe;
• inclinometer or laser level;
• hammer or screwdriver.

Before carrying out the work, it will be necessary to calculate the difference between the walls of the building for the slope of the roof. This can be done using a formula with the following indicators:

In this case, W is the distance between the walls of the house, L is the angle of inclination of the roof, H is the difference between the walls.

Determination of the cross-section of a bar or board for arranging a rafter system

Or the boards that will be used for the manufacture of elements of the truss structure depends entirely on their length. So, with a rafter height of 3 m, a material with a cross section from 8x14 cm to 10x12 cm can be used.The height of elements of 4 m will require the use of a board or a beam with a section from 8x18 cm to 10x10 cm. A beam or boards with the largest section of 8x22 cm or 10x20 cm should be used when the length of the roof rafters is at least 5 m.

Carrying out work on the arrangement of the rafter system

In order to make the rafters correctly, you first need to install the Mauerlat. This term refers to a roofing element, usually made from logs or beams. It is in the Mauerlat that every detail of the rafter structure is installed. Thanks to this element, the load from the weight of the rafters is distributed over the entire area of ​​the house. The number of Mauerlats depends entirely on the number of pairs of rafters, since the lower end of each rafter element is fixed in a groove cut in the Mauerlat.

Mauerlats are installed on walls and buildings under construction. At the same time, on the one and on the other hand, its removal beyond the walls of the house should be from 40 to 60 cm. The removal should have the same value along the entire length. Several methods can be used to mount the Mauerlat: fixing with staples, wire winding, fixing with long nails, etc.

In the places where the rafters are attached to the mauerlat, we make grooves that must fully correspond to the spike at the end of each rafter. The grooves should be located at the same distance at least 6-8 cm from the end of the bar or log.

When the required number of Mauerlats of the same length is installed on the walls of the house, you can start installing the rafter system. The structure is made taking into account the step between the rafters no more than 2 m. If the thickness of the timber or board is minimal (about 40 mm), the step can be made smaller.

In order for the roof rafters to be folded at the desired angle, a template is made of boards based on the calculations according to the above formula. Using this template, all the necessary distances are measured and a spike is cut out, corresponding to the groove in the Mauerlat. On the basis of the prepared template, spikes are made at the bottom of all rafter elements.

At the upper end of the elements, grooves are cut at a certain angle for attaching the ridge girder. The size of the angle depends on the angle of inclination of the roof and the size of the ridge bar. The ridge can be attached above the center of the rafters or, conversely, under them. The use of a ridge increases the rigidity of the rafter structure.

You can fasten the rafters without a ridge girder: this method is usually used in the construction of small buildings, the roof span of which is less than 4.5 m.In this case, the upper ends of the rafter system elements are cut at a certain angle so that each pair has a groove and a spike, which will be securely fastened to each other.

The prepared rafters are raised to the base of the roof and mounted in the grooves on the Mauerlats. Each post can be secured with either staples or long nails. In the case when a ridge girder is used, it is advisable to install additional posts under the rafters, which will exclude the possibility of their sagging. The posts are installed from a board, the cross-section of which is less than the cross-section of the rafters, and are fixed on the Mauerlat.

Once the roof rafters have been installed, the sheathing needs to be prepared for the roof anchoring. The type of lathing depends entirely on what kind of roofing will fit on the roof elements. For example, a crate with a pitch of 10 to 50 cm is suitable for fastening metal tiles, slate and sheet roofing materials. The lathing, the distance between the elements of which will be no more than 1 cm, will be required for roll materials, sheet slate or soft roofing.

If you need to make a rafter structure with your own hands, you can use the above recommendations. If the work is done carefully and accurately, the roof of the house will be reliable and will last for a long time.

A gable roof or gable roof is a roof with two slopes, i.e. having 2 inclined surfaces (slopes) of a rectangular shape.

The gable roof frame, due to its design features, ideally combines ease of installation and maintenance with reliability and durability. These and many other parameters make the construction of a gable roof a practical and rational solution for private and commercial housing construction.

As part of this article, we will consider how to make a gable roof rafter system with your own hands. For effective perception of the material, it is presented in the form of step-by-step instructions from A to Z, from selection and calculations, to the installation of the Mauerlat and the lathing under the roof. Each stage is accompanied by tables, diagrams, drawings, pictures and photos.

The popularity of the roof with a house is due to a number of advantages:

• design variability;
• simplicity in calculations;
• natural water flow;
• the integrity of the structure reduces the likelihood of leaks;
• profitability;
• preservation of the usable area of ​​the attic or the possibility of arranging the attic;
• high maintainability;
• strength and durability.

Types of gable roof

Installation of a gable roof truss system depends, first of all, on its design.

There are several options for gable roofs (types, types):

The most common version of the roof device due to its simplicity and reliability. Thanks to symmetry, an even distribution of loads on the load-bearing walls and the Mauerlat is achieved. The type and thickness of the insulation do not affect the choice of material.

The cross-section of the timber makes it possible to provide a margin of bearing capacity. There is no chance of bending the rafters. Supports and spacers can be placed almost anywhere.

An obvious drawback is the impossibility of arranging a full-fledged attic floor. Sharp corners create blind spots that are unusable.

The arrangement of one angle more than 45 ° leads to a decrease in the amount of unused area. It becomes possible to make living rooms under the roof. At the same time, the requirements for the calculation are increasing, since the load on the walls and foundation will be unevenly distributed.

This roof structure allows you to equip a full second floor under the roof.

Naturally, a simple gable roof rafter differs from a broken one, not only visually. The main difficulty lies in the complexity of the calculations.

The structure of the rafter system of a gable roof

Do-it-yourself roof construction of any complexity presupposes knowledge of the purpose of the main structural elements.

The locations of the elements are shown in the photo.

• Mauerlat... Designed to distribute the load from the rafter system to the load-bearing walls of the building. For the arrangement of the Mauerlat, a bar of solid wood is selected. Preferably larch, pine, oak. The cross-section of the timber depends on its type - solid or glued, as well as on the estimated age of the structure. The most popular sizes are 100x100, 150x150 mm.

  Advice. For a metal rafter system, the Mauerlat must also be metal. For example, a channel or I-profile.

• Rafter leg... The main element of the system. For the manufacture of rafter legs, a strong beam or log is used. Legs connected from above form a truss.

The silhouette of the truss determines the appearance of the structure. Examples of farms in the photo.

The parameters of the rafters are important. They will be discussed below.

• Tightening- connects the rafter legs and gives them rigidity.

• Run:

• Ridge run, mounted at the junction of one rafter to another. In the future, a roof ridge will be installed on it.

• Side girders, they provide the truss with additional rigidity. Their number and size depend on the load on the system.

• Rafter rack- vertically located timber. Part of the load from the weight of the roof is also taken over. In a simple gable roof, it is usually located in the center. With a significant span - in the center and on the sides. In an asymmetrical gable roof - the installation location depends on the length of the rafter. With a broken roof and the arrangement of one room in the attic, the racks are located on the sides, leaving free space for movement. If there are two rooms, the racks are in the center and on the sides.

The position of the pillar depending on the length of the roof is shown in the figure.

• Brace... Serves as a support for the rack.

Advice. Installing the brace at an angle of 45 ° significantly reduces the risk of deformation from wind and snow loads.

In regions with significant wind and snow loads, not only longitudinal struts (located in the same plane with the rafter pair) are installed, but also diagonal ones.

• Sill... Its purpose is to serve as a support for the rack and as a place for attaching the strut.

• Lathing... Designed for movement during construction work and for fixing the roofing material. Installed perpendicular to the rafter legs.

Advice. An important purpose of the lathing is to redistribute the load from the roofing material to the rafter system.

The presence of a drawing and a diagram indicating the location of all the listed structural elements will help in the work.

Advice. Be sure to add data on the device for the passage of the ventilation shaft and chimney to the gable roof truss system diagram.

The technology of their device is determined by the type of roof.

The choice of material for rafters

When calculating the material for a gable roof, you need to choose high-quality wood without damage and wormholes. The presence of knots for beams, Mauerlat and rafters is not allowed.

For boards, there should be a minimum of knots, and they should not fall out. The wood must be durable and treated with the necessary preparations that will enhance its properties.

Advice. The length of the knot should not exceed 1/3 of the thickness of the bar.

Calculation of the rafter system of a gable roof

The calculation of the parameters of the material is an important stage, therefore, we present the calculation algorithm step by step.

It is important to know: the entire rafter system consists of many triangles, as the most rigid element. In turn, if the slopes have a different shape, i.e. are an irregular rectangle, then you need to divide it into separate components and calculate the load and the amount of materials for each. Summarize the data after calculations.

1. Calculation of the load on the rafter system

The load on the rafters can be of three types:

• Constant loads... Their action will always be felt by the rafter system. These loads include the weight of the roof, lathing, insulation, films, additional roofing elements, finishing materials for. The weight of the roof is the sum of the weight of all its constituent elements; such a load is easier to take into account. On average, the value of the constant load on the rafters is 40-45 kg / sq.

Advice. To make a margin of safety for the rafter system, it is better to add 10% to the calculation.

For reference: The weight of some roofing materials per 1 sq. M. presented in the table

Advice. It is desirable that the weight of the roofing material per 1 sq. roof area, did not exceed 50 kg.

• Variable loads... They act in different periods and with different strengths. Such loads include: wind load and its strength, snow load, precipitation intensity.

Basically, a roof slope is like a sail and when wind load is taken into account, the entire roof structure can be destroyed.

The calculation is carried out according to the formula: the wind load is equal to the indicator for the region, multiplied by the correction factor. These indicators are contained in the SNiP "Loads and Impacts" and are determined not only by the region, but also by the location of the house. For example, a private house surrounded by multi-storey buildings has less stress. A detached country house or summer cottage is experiencing increased wind loads.

2. Calculation of snow load on the roof

The calculation of the roof for the snow load is carried out according to the formula:

The total snow load is equal to the weight of the snow multiplied by the correction factor. The coefficient takes into account wind pressure and aerodynamic influence.

The weight of snow, which falls on 1 sq. roof area (according to SNiP 2.01.07-85) is in the range of 80-320 kg / sq.

The coefficients showing the dependence on the angle of inclination of the slope are shown in the photo.

Nuance. At an angle of inclination of the slope over 60 ° the snow load does not affect the calculation. Since the snow will quickly slide down and will not affect the strength of the timber.

• Special loads... Such loads are taken into account in places with high seismic activity, tornadoes, and stormy winds. For our latitudes, it is enough to make a margin of safety.

Nuance. The simultaneous action of many factors causes a synergistic effect. This is worth considering (see photo).

Assessment of the condition and bearing capacity of walls and foundations

It should be borne in mind that the roof has a significant weight that can harm the rest of the building.

Determination of the roof configuration:

• simple symmetrical;
• simple asymmetric;
• broken line.

The more complex the shape of the roof, the greater the number of trusses and trusses needed to create the necessary safety margin.

The angle of inclination of a gable roof is determined primarily by the roofing material. After all, each of them puts forward its own requirements.

• soft roof - 5-20 °;
• metal tile, slate, corrugated board, ondulin - 20-45 °.

It should be noted that increasing the angle increases the area of ​​space under the roof, but also the amount of material. What affects the total cost of work.

Nuance. The minimum angle of inclination of the gable roof must be at least 5 °.

5. Calculation of the step of the rafters

The pitch of the rafters of a gable roof for residential buildings can be from 60 to 100 cm. The choice depends on the roofing material and the weight of the roof structure. Then the number of rafter legs is calculated by dividing the length of the ramp by the distance between the rafter pairs plus 1. The resulting number determines the number of legs per ramp. For the second, the number needs to be multiplied by 2.

The length of the attic roof rafters is calculated using the Pythagorean theorem.

Parameter "a"(roof height) is set independently. Its value determines the possibility of arranging a dwelling under the roof, the convenience of being in the attic, and the consumption of material for the construction of the roof.

Parameter "b" equal to half the width of the building.

Parameter "c" represents the hypotenuse of the triangle.

Advice. To the resulting value, you need to add 60-70 cm. For sawing and carrying the rafter leg over the wall.

It should be noted that the maximum length of the bar is 6 lm. Therefore, if necessary, the rafter beam can be spliced ​​(building, docking, joining).

The method of splicing the rafters along the length is shown in the photo.

The width of the roof rafters depends on the distance between the opposing load-bearing walls.

7. Calculation of the cross-section of the rafters

The cross-section of the gable roof rafters depends on several factors:

• loads, we have already written about it;

• type of material used. For example, a log can withstand one load, a beam - another, a glued beam - a third;

• rafter leg length;

• the type of wood used in construction;

• distance between rafters (rafter pitch).

You can determine the cross-section of the timber for the rafters, knowing the distance between the rafters and the length of the rafters, using the data below.

Rafters section - table

Advice. The larger the step of installing the rafters, the greater the load falls on one rafter pair. This means that the cross-section of the rafters needs to be increased.

Sizes of lumber (timber and boards) for a gable rafter system:

• thickness (section) of the Mauerlat - 10x10 or 15x15 cm;

• the thickness of the rafter leg and tightening is 10x15 or 10x20 cm. Sometimes a 5x15 or 5x20 cm bar is used;

• run and brace - 5x15 or 5x20. Depending on the width of the leg;

• rack - 10x10 or 10x15;

• bed - 5x10 or 5x15 (depending on the width of the rack);

• thickness (section) of the roof lathing - 2x10, 2.5x15 (depending on the roofing material).

Types of gable roof truss system

For the roof structure under consideration, there are 2 options: layered and hanging rafters.

Let's consider each type in detail in order to make an informed choice.

Hanging rafters

They are used with a roof width of no more than 6 lm. Installation of hanging rafters is carried out by attaching a leg to a load-bearing wall and a ridge girder. The design of the hanging rafters is special in that the rafter legs are under the influence of a bursting force. Hanging rafters with a tie between the legs reduce its influence. The tightening in the rafter system can be wooden or metal. Puffs are often placed at the bottom, then they play the role of load-bearing beams. It is important to ensure that the fastener is securely attached to the rafter leg. Because a bursting force is also transmitted to it.

Advice.
The higher the tightening is, the more strength it should have.
If the tightening is not installed, the load-bearing walls can simply "disperse" from the pressure created by the rafter system.

Sliding rafters

They are used for arranging roofs of any size. The design of the layered rafters provides for the presence of a bench and a stand. The bed lying parallel to the Mauerlat takes on part of the load. Thus, the rafter legs are, as it were, inclined to each other and are supported by a stand. The rafter legs of the layered system work only for bending. And the ease of installation also tilts the scales in their favor. The only drawback is the presence of a rack.

Combined

Due to the fact that modern roofs are distinguished by a large variety of shapes and complexity of configurations, a combined type of rafter system is used.

After choosing the type of rafter system, you can accurately calculate the amount of materials. Record the calculation results. At the same time, professionals recommend drawing up drawings for each roof element.

Installation of the rafter system of a gable roof

After the rafters of the gable roof have been calculated, you can proceed with the installation. We will divide the process into stages and give a description of each of them. You will get a kind of step-by-step instructions containing additional information on each stage.

1. Mounting the Mauerlat to the wall

The beam is installed along the length of the wall on which the rafters will rest.

In log cabins, the upper crown plays the role of Mauerlat. In buildings built of porous material (aerated concrete, foam concrete) or brick, the Mauerlat is installed along the entire length of the load-bearing wall. In other cases, it can be installed between the rafter legs.

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Since the length of the Mauerlat exceeds the standard dimensions of lumber, it has to be spliced.

The connection of the Mauerlat to each other is done as shown in the figure.

How to connect the Mauerlat?

The bars are washed down only at an angle of 90 °. The connection is made using bolts. Nails, wire, wooden pins are not used.

How to mount the Mauerlat?

The Mauerlat is installed on the top of the wall. The mounting technology provides for several ways of attaching the Mauerlat:

• strictly in the center of the bearing wall;
• offset to one side.

Advice.
Mauerlat cannot be placed closer than 5 cm to the outer edge of the wall.

To protect the timber for the Mauerlat from damage, it is laid on a layer of waterproofing material, which is most often an ordinary roofing material.

The reliability of the Mauerlat fastening is an important aspect of construction. This is because the roof slope is like a sail. That is, it is experiencing a strong wind load. Therefore, the Mauerlat must be firmly fixed to the wall.

Methods for attaching the Mauerlat to the wall and rafters

Anchor bolts. Ideal for monolithic construction.

Wooden dowels. Used for log cabins and beams. But, they are always used with additional fasteners.

Staples.

Hairpin or fittings. It is used if the cottage is built of porous materials (aerated concrete, foam concrete).

Sliding mount (swivel). A bundle in this way allows you to ensure the displacement of the rafter legs when the house shrinks.

Annealed wire (knitting, steel). Used as an additional mount in most cases.

2. Production of roof trusses or pairs

Installation is carried out in two ways:

• installation of beams directly on the roof. It is not often used, since it is problematic to carry out all work, measurements, trimming at height. But it allows you to completely complete the installation yourself;

• assembly on the ground. That is, individual elements (triangles or pairs) for the rafter system can be assembled at the bottom, and then raised to the roof. The advantage of such a system is the faster execution of work at height. And the disadvantage is that the weight of the assembled truss structure can be significant. To lift it, you need special equipment.

Advice. Before assembling the rafter legs, you need to apply the markings. It is very convenient to use templates for these purposes. The rafter pairs assembled according to the pattern will be exactly the same. To make a template, you need to take two boards, the length of each of which is equal to the length of one rafter, and are connected to each other.

3. Installation of rafter legs

The collected pairs go upstairs and are installed on the Mauerlat. To do this, at the bottom of the rafter legs, you need to make a wash.

Advice. Since the slots on the Mauerlat will weaken it, you can only make cuts on the rafter leg. In order for the saw to be the same and fit snugly to the base, you need to use a template. It is cut from plywood.

The ways of attaching the rafter leg are shown in the figure.

You need to start the installation of rafter pairs from opposite ends of the roof.

Advice. To properly position the rafter legs, it is best to use temporary struts and struts.

A string is pulled between the fixed pairs. It will simplify the installation of subsequent rafter pairs. And also, it will indicate the level of the skate.

If the rafter system is mounted directly on the roof of the house, then after installing the two outer rafter legs, the ridge support is installed. Further, half of the rafter pairs are attached to it.

It is worth noting that the opinions of professionals differ on this issue. Some advise using a staggered fastening order, which will evenly distribute the increasing load on the walls and foundation more evenly. This procedure involves the installation of one rafter in a checkerboard pattern. After part of the rafter legs are installed, the missing parts of the pair are mounted. Others insist on sequential editing of each pair. Depending on the size of the structure and the configuration of the truss, the rafter legs are reinforced with struts and struts.

Nuance. Additional structural elements are connected by cutting. It is preferable to fix them with construction brackets.

If necessary, you can lengthen the rafter leg.

Methods for splicing rafter legs are shown in the photo.

Advice. The way in which the Mauerlat is lengthened (washed down at 90 °) cannot be used in this case. This will loosen the rafter.

4. Installation of the gable roof ridge

The ridge roof assembly is made by connecting the rafter legs at the top.

Roof ridge device:

• Method without using a support bar (see fig.).

• The method using a rafter bar. The beam is needed for large roofs. In the future, it can become a support for the rack.

• Timber overlay method.

• A more modern version of making a ridge knot can be considered the method shown in the photo.

• Cutting method.

After the rafter system has been installed, we make the capital fastening of all structural elements.

5. Installation of roof battens

The lathing is mounted in any case, and is designed for more convenient movement along the roof during work, as well as for fastening the roofing material.

The step of the lathing depends on the type of roofing material, for example:

• for metal tiles - 350 mm (the distance between the two lower boards of the sheathing should be 300 mm).
• for corrugated board and slate - 440 mm.
• we lay a continuous crate under the soft roof.

Gable roof rafter system with an attic - video:

Conclusion

As you can see, despite the apparent simplicity, the installation of the gable roof truss system contains many pitfalls. But, based on the recommendations given, you can easily build a reliable structure with your own hands.

The rafter system is the roof frame, which is the base for the decking of the roof coverings.

The rafter system is designed to withstand the load of the roof, taking into account natural loads: winds, snow, rain.

The roof option is approved at the design stage.

The purpose of the roof includes several functions: warmth in the house, protection of the room from natural phenomena, therefore the rafter system must be given special attention.

You can read how to calculate the rafter system.

It is customary to classify rafter systems so that the task of choosing a future roof option is easier to solve:

• Single slope... The most simple ones. More suitable for utility rooms, baths, small private houses, gazebos... Provides for an inclined position of the structure at a slight angle (no more than 25 °);
• Gable. Used for small houses and summer cottages... They look like a triangle, in which the rafter boards are connected by a beam and are at a certain angle;
• Gable broken lines... They have two slopes with a fracture, due to which it is possible to increase the area of ​​the attic;
• Three-slope (half-hip). Have two trapezoidal slopes, which are connected by one end triangular slope (hip);
• Four-slope (hip). Used for residential buildings, require significant labor costs. They have two end triangular slopes and two trapezoidal ones;
• Hip-roof. Used for square-shaped buildings. They consist of four triangular slopes, the upper corner of which is connected in the center of the roof;
• Multi-pliers. Consist of trapezoidal or other slopes of different shapes, connected to each other.

The most suitable designs for - and broken gable. There are others, but they are less common and not as practical as the ones listed above.

Roof structures are also classified into:

• Hanging. With this type of roof frame due to the absence of load-bearing walls in the room;
• Forced. Rafter installation option, providing support on a load-bearing internal wall or support in a building.

The calculation of the material for the roof frame when designing a building is based on the intended configuration and load. Do-it-yourself rafters are not difficult to do, it is important to get down to business wisely.

Roof systems of the layered and hanging type

Calculation of the load on the rafters

To correctly calculate the load on the rafters, it is necessary to take into account many factors that can affect the severity of the structure.

Important metrics to consider:

• Constant load: includes the mass of the roofing cake, covering material;
• The load is temporary: constant and maximum amount of snow, rain, intensity of wind gusts, and in areas with high seismic activity - the action of storm winds, tornadoes, hurricanes.

In addition, one should bear in mind the mass and strength of the rafter legs, and also pay attention to the fastening of the rafters of the gable roof and the installation option.

Truss systems diagram

The distance between the rafters of the gable roof and the thickness of the rafter

The pitch of the gable roof rafters is the empty space between the rafters. The functionality of the roof depends on the correct calculation of the step. Typically, the step is about a meter.

For a more accurate calculation of the distance between the rafter boards, there is a certain calculation scheme:

1. Determine the length of the slope.
2. The length of the ramp is divided by the distance between the rafters.
3. To determine the number of rafter boards, add one to the resulting value and round up towards a larger value. This is how they determine how many boards are needed per slope.
4. The length of the slope is divided by the number of boards, the distance between the rafters is obtained.

This calculation is not always final.

Additionally, you should take into account the load of the roofing (its weight), the thickness of the rafters, as well as the dimensions of the rafters for a gable roof.

The thickness of the rafter board largely depends on the covering material:

• . Boards are used with a section of 5x20 cm at a step from 60 to 90 cm with a sheathing flooring with a section of 4x5 cm;
• . Rafter boards - 5x15 cm, step - from 60 cm to 95 cm;
• . The section of the board is 6x18 cm or 5x15 cm, the distance between the bars is from 80 cm to 130 cm;
• . The rafter section is 5x15 cm, 5x10 cm with a step from 60 cm to 90 cm;
• . The cross-section of the timber is the same as for the corrugated board at a step of 60-80 cm.

All indicators should be taken into account and the thickness of the rafters should be accurately calculated so that there is no excessive load on the foundation.

Incorrect calculation of the length of the rafters of a gable roof, as well as incorrect calculation of the step indicators, can lead to sagging of the roof.

Installing the rafters of a gable roof with your own hands requires taking into account the weight of the rafter board and all additional fasteners of the structure.

What the rafter system consists of

Rafter structure - a complex system and installing a gable roof rafter system is not an easy task. Rafter system consists not only of rafter boards, but also of other additional elements:

• Mauerlat. An element that distributes all the load evenly to the supports;
• Run. The boards that fasten the legs of the rafters: at the top - the ridge, on the side - the side run;
• Puffs. A connecting beam that prevents the rafter legs from diverging;
• Braces, racks. Bars that fix the stability of the rafters, resting on the bed;
• . A lattice of bars, which is applied perpendicular to the rafters. Transfers the load of the covering material to the rafter frame;
• . Connecting beam, which serves as a union of the roof slopes;
• Filly. If the length of the rafter legs is insufficient, they are mounted to form an overhang;
• Roof overhang. It extends beyond the bottom line of the slope to prevent precipitation from entering the walls.

The rafter system implies rafters, braces, braces and racks located in the same plane. They are positioned in such a way that the main load of the roof structure falls vertically on the external load-bearing walls. Therefore, the manufacture of gable roof rafters is a very important process.

What does the gable roof rafter system consist of?

Installation of a rafter system with layered rafters

The layered rafter system is used when the span does not exceed 6.5 meters.

If there are supporting structures inside the building, it is possible to install additional racks.

The main support of the rafter legs is the Mauerlat.

Mauerlat installation

Before installing the Mauerlat, you must install the armpole. It consists of a formwork in which the reinforcement is laid and poured with concrete. At the base, when the concrete has not yet hardened, studs are installed, to which the Mauerlat is then attached.

Mauerlat is a beam that is laid on a support (load-bearing wall) and is the base of the rafter frame. A layer of waterproofing material is pre-laid. If the length of the timber is not enough for the length of the wall, then it is increased.

• Check the equality of the diagonals. A discrepancy of a few centimeters can lead to re-equipment of the frame;
• Fix the corners of the Mauerlat;
• Attach the Mauerlat with pins or wire. The studs are tightened in two steps, having previously drilled holes for them.

The stability of the roofing structure depends on how firmly the Mauerlat will be installed.

Therefore, it is necessary to take seriously the fastening of the Mauerlat to the bearing support.

Mauerlat installation

Sill

After the Mauerlat has dried (after 5 days), mark the installation of the bed on the Mauerlat bar: its axis should be with the same indent on each side of the Mauerlat bar. The bed is attached to a two-layer waterproofing layer with anchor bolts. To the wall from the inside, the bed should be fastened with wire twists or staples. Next, markings are made for installing the rafters.

Installation of the rafter system of a gable roof

The anchor points of the layered rafters are the walls and posts inside the frame. The rafters are mounted with hinged attachment points. When using sliders for fastening, a slight lowering of the roof frame is ensured in the first years of the roof's service.

This installation method is necessary to prevent distortions., as in the early years the building subsides a little.

The rafter beams should be fastened either by installing them in the prepared grooves and reinforced with fasteners, or by attaching the board overlays.

Installation of rafters

Ridge knot

The rafters are connected end-to-end, cutting off the edge of the bar so that the angle when joining opposite beams corresponds to the angle of the slope. The rafters are hammered under the ridge with nails. An option is possible in which the beams are connected with bolts, a nail or a hairpin, that is, with an overlap.

If necessary (if provided by the project), a cut is made in the rafter beams to fasten the ridge beam (run).

Ridge knot

Racks

The uprights are attached with a short span - in the center, on the sides and in the center - with a wider roof base. Fastening is done vertically from the ridge to the inner wall.

Run

Girder - connecting beam for securing the rafter legs. Bolts or brackets to the rack.

Installing filly

The final stage in the installation of the layered system is the installation of fillies with a short length of rafter legs for the overhang. To install the visor, it is necessary to install additionally small rafter boards.

Installation of a rafter system with layered rafters

Diy gable roof rafter system: installation with hanging rafters

Rafter system equipped with hanging rafters, is a triangular design, where the sides are the rafters, and the base is a tightening connected to the lower heels of the rafters.

Installation of a hanging type rafter frame can do without installing a Mauerlat: a board that is fixed to a two-layer waterproofing can replace it.

If the structure has a large span, then struts, headstock, crossbars are attached to it.

There are no racks in the hanging system.

Puffs

The brace is the longest beam of the roof frame. To prevent it from sagging, it is necessary to fasten the headstock - boards that are attached to the top of the structure on one side, and to the tightening on the other. Fastened with bolts or wood strips. Threaded clamps can be used to adjust the slack.

The device of the rafter system

Installation of brace beams

The headstock can be supplemented by strut beams, forming a rhombus, where two struts are the lower sides, and the rafter boards are the upper ones, the upper corner is the ridge. Thus, the struts rest against the headstock, distributing the load.

Strut beams

Rafters

Hanging rafters are mounted like a layered one. When installing attics, the tie is installed closer to the ridge, providing more space under the ceiling. In this case, the tightening is secured by a bolt-in slot.

ATTENTION!

When installing a hanging system, a prerequisite for installation is the accuracy of calculations and the strength of the rafters and tightening.

The presence of errors leads to a displacement of the axes of the elements of the system, which provides a skew of the structure.

This photo will tell you how to install rafters for a gable roof:

Installation of rafters

Hanging rafters

How to strengthen the rafters of a gable roof

It is necessary to strengthen the rafters of a gable roof when the calculation of the load is performed incorrectly or defects in the frame are found.

Strengthening can be done with:

• Beams, which are installed in order to transfer the load to them;
• Installation of struts with an inclined mount with an emphasis on the bed;
• Overlapping double-sided slats;
• Increasing the cross-section of the rafter beam in the place of supports on the brace by imposing planking from boards with nails or bolts;
• A wall of boards which are attached to the rafters in places of expected snow accumulation to increase the bearing capacity of the rafters.

You can resort to strengthening the Mauerlat bar and the base of the rafter bar. Due to the increased humidity and reduced ventilation, these parts of the frame are more susceptible to rotting, therefore, when arranging the roof special attention must be paid

The rafter system is the "skeleton" of any roof structure. The reliability, quality and durability of the roof made directly depends on the correctness of its manufacture and installation. If desired, you can cope with the arrangement of the rafter system yourself. Do you want to know how? Check out the following guide!

There are layered and hanging rafter systems. According to statistics, layered structures are most often used. When arranging such a system, they run into the Mauerlat. The function of the central part is performed by a simple ridge run. To increase the strength of the system, support beams are installed.

In the case of hanging rafters, the structure of the system is completed with additional posts, which contribute to the optimal distribution of the load over the entire area of ​​the roof structure.

Take an extra pair of nails and fix the angle set between the planks. At this point, the template is ready. Additionally, fix it with a crossbar. To prevent the set slope angle of the roof slope from changing under the influence of loads, fasten the crossbar with self-tapping screws.

Be extremely careful when creating your template. Even due to the slightest deviations, the entire structure can deteriorate.

Next, we make a new template for preparing mounting cuts on the elements of the system. Use 0.5cm plywood. Use a 2.5cm plank for reinforcement. Select the dimensions of the grooves taking into account the cross-section of the used rafters.

Using ready-made templates, we make cuts and start assembling the farm.

Video - Gable roof rafter system

Truss assembly order

The structure includes support legs and connecting components. The farm resembles a triangle. Perform the work in the specified sequence, and the finished structure will be able to adequately transfer all incoming

The farm can be done on the ground with a further rise upward or directly on the roof. The first option is simpler and easier to carry out.

We collect the truss in the following order. First, we cut the prepared material to the desired size, join the bars with the upper edges and fasten them with screws. To prevent the appearance of cracks in the fastening points, we pre-drill holes in the bars with a diameter slightly smaller than the size of the fasteners.

We also use a crossbar to connect the rafter legs. We fix it half a meter below the upper attachment point of the elements. The crossbars will help to increase the rigidity of the structure and eliminate the risk of deflection. The crossbar is fastened in the recesses, previously equipped in the rafters by cutting.

If necessary, the rafters are cut at an angle, if this is required by the features of the roof structure being equipped.

Installing a truss truss

We install roof trusses in the following sequence:

• we mount extreme farms;
• we fix the central trusses.

When installing extreme farms, we adhere to the following important rules:

After completing the installation of the extreme trusses, we proceed to fixing the central and subsequent structures, if their placement is provided for by the project. The optimal pitch for installing trusses is 100 cm.

To secure the central rafter triangle, we use temporary jibs. After the visor is installed, the jibs can be removed. The recommendations for fixing the central and other trusses are the same as in the case of the extreme structures.

After installing all structural elements, we proceed to fastening the lathing and further arranging the roofing system: moisture, heat and vapor insulation, as well as the installation of the selected topcoat.

Happy work!

Prices for various types of fasteners for rafters

Fasteners for rafters

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Video - Hip roof. Rafter system