During the construction of private houses, the roof is most often made gable. There are reasons for this. First, it is reliable. Handles wind and snow loads well. The second - it is compatible with any roofing. The third is relatively inexpensive. The fourth is a simple design that is difficult to spoil. Fifth - it looks attractive. All this, and also the fact that a do-it-yourself gable roof is built without special knowledge, determines its popularity.

Do-it-yourself assembled gable roof ready for installation of roofing

Step-by-step installation of a gable roof

As you saw above, there are a lot of truss systems. Accordingly, when assembling each has its own characteristics, but in general the order is the same. It is necessary to say about the general step: pre-drying and processing of wood. This step is required if you bought fresh lumber, not dried.

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

Timber must be dried in ventilated stacks. To do this, they are laid in short pieces of boards. They are placed a meter from the edges and further through the meter. Spacers must be installed under the bottom

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

Mauerlat

The assembly of the gable roof truss system begins with the installation of the Mauerlat. It must be set strictly horizontally, therefore, before starting installation, the horizontalness of the wall to which it is attached is carefully checked, if necessary, it is leveled with cement mortar. You can continue work after the solution gains 50% strength.

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

There are several ways to connect walls and Mauerlat:

• In the masonry (in the reinforced concrete belt) a smooth rolled wire of large diameter is fixed (two ends stick up). Holes are then made in the board in the necessary places, into which the wire is threaded. She then twists and bends.
• Studs with a diameter of at least 12 mm are immured in the wall. Under them, holes are made in the Mauerlat, a beam / board is placed) and tightened with nuts with wide washers.
• Aligning the beam or board along the outer or inner edge of the wall, take a drill with a diameter of 12 mm, make holes for the anchor bolts. They (the same diameter of 12 mm) are hammered to the very hat, then tightened with a key.

The distance between the studs (wire) should not be more than 120 cm. Cut-off waterproofing must be laid on the wall (belt) under the Mauerlat. It can be rolled roofing felt or waterproofing in two layers, it can be smeared with bituminous mastic.

Rafter installation

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

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

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

On the one hand, this is convenient - it is easier to work on the ground, with a high assembly speed, the accuracy is high: one farm is not much different from the other, which simplifies the procedure. But it can be difficult to raise finished trusses, especially for large buildings. To make this easier, two inclined boards are installed, which at one end rest against the ground, and the other sticks out a little above the wall. Farms are brought closer to this “lift”, one by one they are installed below, ropes are tied and pulled along the boards to the roof. In the absence of a winch or crane, this is the most acceptable method.

The assembly of rafters requires certain knowledge: how and in what order to mount them, how to mark and make cuts. See the video for the assembly of one of the schemes with a headstock.

Assembly order of the truss system

Everything, the do-it-yourself gable roof is assembled and ready for installation of roofing material.

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

Features of the installation of the truss 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 truss system. If the elements are fixed rigidly, the roof may fall apart. Therefore, the mounts are made floating. There are special sliding fasteners, which in this case attach the rafters to the upper crown and to the girders, if any (see photo).

In order for the rafter to move freely during shrinkage, its long part is fixed strictly parallel to its edge, and the support is placed strictly perpendicular. If necessary, a platform is cut out under it. Mark the mount so that the hook is in the lowest position or near it. They are mounted on special self-tapping screws that come with the kit (ordinary ones do not fit). If the installation is done 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, it is called "slippery". How to attach the slippery to the beam, see the video.

Video on assembling and installing a gable roof truss system

It is not easy to build a gable roof with your own hands: there are a lot of subtleties and nuances, there are different ways of fastening, building up. Describing them in words is a thankless job. This is the case when it is better to see. Below is a selection of videos that you might find useful.

Video report on how a gable roof is made

The story of the owner of the house about the stages of construction. There are interesting technical points that may be useful.

Two types of rafter connection: rigid and sliding

Video about the two most problematic types of connections.

How to determine the angle of the rafters

Full video report on the assembly of the truss system

This movie is just under an hour long, but the entire process is shown from start to finish with plenty of detail. The roof is placed on, but when installed on buildings of a different type (except for wooden houses), there is no difference.

A good foundation does not mean that the house will stand "faithfully and truly" for many years. Another extremely important component is a reliable and high-quality roof truss system. Let's see how it works in the case of a pitched roof, what types it is and what elements it consists of.

Roof truss systems

What should be the rafters for roofs

Here are some types of rafters that are most often used in modern construction:

• metal is difficult to change, but this material is durable;
• wooden ones are easy to use and change, but require additional processing;
• wooden I-beams (made of timber and OSB) are even with a maximum length of up to 12 meters, but the cost is higher than a conventional wooden system;
• reinforced concrete are not amenable to change at all, but they are distinguished by a long service life;
• mixed or combined systems.

Each of them has its pros and cons, which include strength, price, ease of installation, the possibility of small changes associated, for example, with inappropriate dimensions, interaction with the environment. In this material we will talk about the most popular material for the manufacture of rafters - wood. Let us highlight the main tasks that are set for structures of this type.

First, and most importantly - strength each element. The roof must not warp or move. The basis of the construction of the rafters is a triangle. It is in the form of a triangle that trusses (frames) are made that are attached in parallel. Fixed and rigid, they "lead" the entire structure.

Small mass. A heavy roof is extremely bad. Therefore, most elements are made from wood. If the weight of the roofing system is large, then it is reinforced with a metal frame. A basis - coniferous breeds of a tree of small humidity.

How requirements the tree should answer:

• 1-3 varieties. No chips, knots or cracks.
• Wooden elements should not be less than 5 cm in thickness, and with an area of ​​​​up to 45 square meters. cm.
• The maximum length of a beam made of coniferous wood should not exceed 5-6 m.
• Mauerlat and purlins are made exclusively from hardwood.

The main structural elements of the rafters

Any owner planning the construction of a truss system must be aware of what it consists of.

1. Mauerlat. The basis of the whole structure. With the help of this element, the correct load is established on all load-bearing elements of the house.
2. rafter leg. The slope of the slope is touched, gives the roof an attractive appearance, securely fixes the structural parts of the system.
3. puff. Does not allow the legs to "disperse". Holds them firmly at the bottom.
4. Run. Fastens the rafter legs at the top of the system (ridge run) and on the sides (side run).
5. crate. Mounted strictly perpendicular to the beams. It is made from cut timber or boards.
6. Racks / struts. "Add" to the legs even more durability.
7. Overhang. Protects the main structures of the building from various natural precipitation.
8. Skate. The place where the slopes are fixed.
9. Filly. Create an overhang. Necessary in the case when the rafters do not have the required length.

Details of truss systems on the example of a gable roof that can be used for various roof structures

Let's deal with such constituent elements of the truss system as a farm. It is made flat, and, in addition to stretching, it includes braces and the beams themselves. All these parts are fixed in such a way that the load on the main structures is vertical.

In the case when the span is quite large, the farm is made of several components. The lower part of the truss is the attic ceiling. The exact number of farms is determined after serious calculations at each specific site.

Types of truss systems of different types of roofs

All design options are determined by two main types of truss systems: hanging and layered.

hanging

Ideal for gable roof types, with small spans - up to 5 m, without internal partitions. The lower support is Mauerlat. In such a system, tightening is used, which reduces the thrust of the structure on the main supports of the building.

Hanging roof structure

Hanging rafter beams are located below - they also play the role of floor beams. In the case when the floors were made of reinforced concrete structures, they can also be puffs of the system.

Important extras:

• You should not use the legs as the main supporting element for the roof overhang. A more optimal option is a filly (provided that the overhang has a width of no more than 1 m.). The leg, with this solution, transfers the load over its entire plane to the Mauerlat.
• When the wood has a moisture content of more than 20%, it is worth preparing in advance for the fact that after drying the system will begin to “walk”. The solution is to use bolts as fasteners, which can always be tightened. But, even more "advanced" option - "powerful" mounting screws.
• At the top of the roof, it is imperative to fix the wind board (should go from the Mauerlat itself to the top of the ridge). The corner is organized from the attic. This is necessary to create the most durable roof, resistant to wind loads.

Layered

They are used for roofs with spans of 9-15 m. At the top, such rafters are mounted on a ridge run, at the bottom - on a Mauerlat.

Layered truss system

If the span is more than 15 m, then instead of the ridge run, two side ones are mounted, which are additionally attached to the racks. In the case when an attic will be created, a wall is used as a support for the layered beams.

Peculiarities:

• Any structural part of such a system should not be thicker than 5 cm.
• The surfaces of the elements should be as smooth and machined as possible.
• Very carefully you need to consider the calculation of the loads on each structural element.
• Mauerlat must be located strictly in a horizontal position relative to the vertical supports.
• Symmetry must also be adhered to when mounting struts with racks.
• High-quality ventilation is a guarantee that your rafter system will not rot in the future.
• At the junction points of elements with stone or brick, good waterproofing is needed.

Depending on the shape of the roof chosen by the developer, its frame will also be different. We offer to explore various options for the most popular upper house designs.

Shed roofs

They are made at an angle of 13-25 degrees, such roofs have the simplest (in terms of manufacturing and installation) rafters. In the case of a small building with spans up to 5 m, a layered system is used. In the case when spans are more than 5 m, trusses are additionally used.

gable

It's also a pretty simple option. Especially when an attic or attic floor is equipped under such a roof. Tilt angles - 15-63 degrees. If the capital partitions are located at a distance of up to 6 m (relative to each other), hanging rafters are mounted. For running house sizes of 6x6 or 9x9 meters, we recommend using the following roof arrangement schemes.

Recommended scheme for mounting a hanging truss system for a gable roof

Increasing the size of the house, it is necessary to modify (strengthen) the structure. In such cases, it is necessary to use layered technology.

Gable roof options for spans over 10 meters: using a layered truss system

Hip or four-slope

Rules for the construction of a hip roof truss system

With angles of inclination of 20-60 degrees, and spans of no more than 13 m. A prerequisite is internal reinforcing elements. For roofs of this type, trusses are used, or rafters are mounted for roofs of a layered type.

broken roof

Installation of sloping roof rafters

In its lower part it can have a slope of up to 60 degrees, in the upper part it is gentle. In view of this feature, the attic area becomes somewhat larger. The same types of rafters are used as in the version with hipped roofs. But, it is recommended to use farms.

Additional elements

To create the most durable roof, each component of the structure must be very firmly connected to the frame and other elements. In this case, it is extremely important to take into account the force of the wind and the direction of possible mechanical loads.

Moreover, it is worth paying attention also to wood. It may crack due to drying out. Therefore, it is important to create a design in which each element will "work" as smoothly as possible.

Previously, all structural elements of the rafters were fixed with notches. But, it was not too "cheap and economical pleasure", since it is necessary to take wooden elements of a large section.

Methods for attaching rafters to the Mauerlat and ridge run

So, today, not cuttings are used for fasteners, but special bolts and dowels:

Metal overlays with an anti-corrosion coating are another option for fasteners. They are mounted on the elements of the system using toothed plates or nails. The advantages of such mounts are as follows:

1. Small consumption per unit of wood.
2. Ease of installation.
3. High fastening speed.

Perforated fasteners: corners, plates, timber support

Features of the installation of the truss system and Mauerlat gable roofs

The installation scheme of the truss system in the case of a gable roof

I - Mauerlat, II - rafter leg, III - ceiling.

Using narrow rafter legs is a "direct path" to system sagging in the future. To prevent this, you need to use a special lattice - reinforcement, which includes struts, racks and crossbars. To create it, you need to take wood with a thickness of 2.2 and a width of 15 cm, or use plates of wood with a minimum diameter of 13 cm.

Roof rafters - the supporting structure of the slopes. It consists of elements that can be interconnected with crossbars, spacers, racks, etc. The material for the support beams, in addition to the most common - wood, can be any - metal, reinforced concrete, or mixed.

Table for calculating the rafter system, depending on the distance between them and the length

Wood (bar) should have a cross section of 40 by 150 to 100 by 250 mm. This figure depends on the distance of the legs from one another, and the number of sediment loads for a particular area (the calculation is carried out separately).

The board should not have more than 5 cm in cross section. The width is directly proportional to the length. For example, if your board is 5 m long, then its width should not be less than 13 cm. The main material of the roof sheathing is also important. When choosing it, you should pay attention to the presence of knots, chips and cracks. If you cannot find the most even wood blocks, then the maximum length of the knots should not be more than 1/3 of the thickness of the wood.

The last step in the installation of roof rafters is to securely fasten each element. Staples and metal corners are the most optimal elements for these purposes. But, in modern construction, bolts are increasingly used.

A roof with two slopes is the most common option for completing the box of a private house. In its manufacture, it is important to correctly select the cross-sections of the supporting elements, securely fasten the nodes and choose the right type of construction. The truss system of a gable roof does not have great difficulties and may well be made by hand.

Classification of truss systems according to the method of support

The structure can be classified in two ways. The first of them is the method of supporting the load-bearing elements. The gable roof truss system of the house in this case includes the following types:

• with layered rafters;
• with hanging rafters.

Roofing with the use of layered rafters involves their support at two points. The design in this case avoids the occurrence of a serious spacer. To do the installation yourself, you will need the following basic elements:

• rafter legs;
• Mauerlat;
• crossbar;
• intermediate racks and struts with a large span of load-bearing beams;
• crate and counter-crate;
• overlays persistent bars.

At the top point, the installation provides for leaning on the crossbar. The installation also provides support at the lowest point - Mauerlat. You can assemble such a structure for a house with your own hands only in two cases:

1. A layered system is possible if the distance between the gables is not large. That is, such an installation is suitable for a small house with your own hands. The greatest length of the structure, which allows the construction of a wooden crossbar without additional reinforcements, is 6 m. For large spans, it will be necessary to install metal beams as a crossbar. When using a wooden beam, it will be necessary to provide intermediate racks, which are located on average every 2 meters. This can be avoided only when using glued laminated timber of a sufficiently large cross section as a crossbar. In this case, a free layout of the space becomes impossible - the racks in the middle of the room cannot be removed.
2. The second option, when it is possible to install a layered gable roof system with your own hands, is the presence of a wall in the middle of the house. The device in this case provides that the beam, on which the rafters will rest at the top point, will transfer the load to the inner wall. In this case, the supporting structure should not be confused with the partition. The partition rests on the floors, and installing the wall of the house with your own hands involves resting it directly on the foundations. Such a device is suitable for buildings with sufficient width, where it makes sense to install a wall fence in the middle.

The second option is hanging rafters. They are more complex in calculation, but they allow the installation in the under-roof space of a free-plan house. The design assumes the absence of a supporting wooden or metal bar in the upper part. Installation involves supporting the rafters only at the lowest point. In the upper part, the bearing beams are securely connected to each other. Installing such a system is like a farm. The design works on thrust, so it is important to prevent excessive horizontal load on the walls of the house. You can do this by doing the following:

• the device of a monolithic belt along the edge of the walls;
• it is necessary to make a reliable fastening of the Mauerlat of a gable roof to the wall of the house with your own hands;
• to eliminate the spacer, a contraction is established.

The fight or screed becomes one of the significant elements of the gable roof of the house. It prevents the expansion of the walls under the action of thrust. The following types of fights can be distinguished:

• located at the attic floor level;
• located at the level of the attic ceiling.

It is worth noting that the second option provides less reliability, since the higher the element is mounted, the stronger the rafters have an effect on it. If the fight turns out to be too long, you need to make it stronger with your own hands. For this, additional elements of the gable roof of the house are installed - suspensions. They connect the skate to the middle of the puff, which prevents it from sagging.

The gable roof truss system with hanging rafters allows you to perform installation with pre-assembly of trusses on the ground, then raise them to the roof and fix them.

This option is only suitable if you have lifting equipment, since the finished gable roofs of the house will become too large and heavy to lift with your own hands.

Classification by type of slope

The second division can be made depending on how the ramp line is designed. The views here suggest the presence of two options:

1. With straight slopes. The easiest way to do. Allows you to get the job done without any hassle. The disadvantage of this do-it-yourself roofing option is the reduction in attic space.
2. With broken slopes. Such types of roofing are more difficult to perform. It is assumed that there is a line along which the angle of inclination changes. The angle of inclination of the lower part of the slope must be made greater than that of the upper. Thus, it turns out to raise the ceiling of the attic and increase the free space. The installation of the roof is carried out with the installation of an additional crossbar at the fracture site.

These types involve a choice between them, depending on the wishes of the future owner of the building.

The main elements of the roof

The rafter system of the gable final part of the building consists of many elements. Installation should begin with a detailed study of each of them and the choice of their sections.

Mauerlat

When installing elements under a metal tile or other coating, it implies the use of a bar with a section of 150x150 or 200x200 mm. It is this size that allows you to most optimally distribute the load. then you need to choose a method of fixing it depends on the material of the walls. There are several options:

1. Frame, timber or log walls do not require the installation of a Mauerlat. In the case of a frame building, the top framing of the walls serves as a support for the rafter legs. during the construction of fences from timber or logs, the upper crown becomes the Mauerlat. It is important to correctly fix these elements in the wall structure.
2. When used for the construction of lightweight concrete, additional reinforcement will be required. Lightweight concretes include materials such as foam concrete, cinder concrete, expanded clay concrete. They can collapse if the roof is not supported centrally on them. To evenly distribute the load, a monolithic reinforced concrete belt is poured along the edge of the walls. During work, a special wire, studs or bolts are laid in it, on which the Mauerlat will be fastened.
3. For brick means, it is possible not to provide a reinforced concrete belt. In this case, to connect with the strapping beam, a wire is inserted into the masonry, which is then wrapped around the Mauerlat and twisted. The second option - one row before the walls are cut, wooden blocks impregnated with an antiseptic are brought into the masonry from the outside. Such plugs and Mauerlat are fastened with staples. It is also possible to use studs and bolts, for fixing which will require pouring a monolithic belt.

An important point is waterproofing.

When installing, it is important to provide roofing material, linokrom or waterproofing at the junction of concrete or brick with wood. This is required to prevent the wood from rotting on contact with material of a different moisture content.

rafters

After fixing the Mauerlat, rafter legs are installed. Their cross section is selected depending on the pitch of the supporting beams, their span, snow load and type of coating. When installing a frame under a metal tile with a step of 60 cm, it is recommended to follow the following recommendations, depending on the span:

• 3 m - 4x15 cm;
• 4 m - 5 \u003d 15 cm;
• 5 m - 5x17.5 cm;
• 6 m - 5x20 cm.

Table of average values ​​of rafter legs

These are average values, in order to perform a more accurate calculation, it is better to contact a specialist or study additional literature.

There are two ways to fasten the rafter legs to the Mauerlat:

• with a notch;
• without her.

Fastening rafter legs to the Mauerlat with and without a notch

In the first case, they washed down on the strapping beam, in the second, a special plank is nailed to the rafters, which becomes a persistent bar. Further, for both methods, the work is performed in the same way. With the help of metal corners, the inclined beam is fixed so that it does not move relative to the design position along the Mauerlat. Additionally, nails are driven in at an angle.

Scheme of fastening rafters with wire and brackets

In addition, you will need to fasten the rafter to the wall. The implementation of this measure is provided for in the regulatory documents. You can do this in two ways:

• on brackets (suitable for wooden buildings);
• using wire twisting (a more time-consuming option, but the only one possible for stone houses).

You can perform fastening according to the norms through one leg. This is necessary for a more secure attachment of the roof to the box of the house.

If you do the work correctly, you can not worry about its condition even in the strongest winds.

Racks, ties, struts

Such elements are most often made of boards. The optimal thickness is in the range of 32-50 mm. Racks are an exception. Here you can use boards with a thickness of 50-100mm. Fastening is carried out on studs or using support bars.

The simplest gable roof in execution is at the same time the most reliable. The availability of do-it-yourself execution does not give rise to self-confidence - before starting work, you need to thoroughly familiarize yourself with the design features in order to competently make decisions and execute them.

Scheme and features of the gable roof device

A gable roof is a roof formed by the intersection of two rectangular slopes at a certain angle. Such a device is the most reliable and simple, so even a person with average carpentry skills can mount a gable roof on their own.

The base of the roof is a truss system that acts as a support for the roofing cake and topcoat. The service life of the roof and the comfort of living in the house depend on its strength and reliability. The truss system, subjected to regular wind and snow loads, must be securely fastened to the building body. This problem is solved with the help of a Mauerlat, which is firmly fixed to the upper plane of the walls of the house. Thus, an almost monolithic system is created that reliably protects the interior of the house from any manifestations of the external environment.

Photo gallery: how you can use the space under a gable roof

Under the gable roof, you can arrange a residential attic A gable roof with a Danish half-hip ennobles the exterior of the building and allows you to increase the size of the attic The attic above the garage can be used to store spare parts, arrange a rest room, or equip a warehouse for household equipment. The area of ​​​​the attic under a gable roof depends on the height of the ridge and the angle of inclination of the slopes

The design of the gable roof truss system

A roof with two opposite slopes is the most common design used in individual housing construction. The line of intersection forms a ridge, and the side openings of the extreme rafter legs serve for the construction of gables - vertically located walls that create a closed under-roof space. To obtain a strong and durable structure, many retaining and reinforcing elements are used, giving additional rigidity to the entire structure. The gable structure is based on a triangle - the most rigid geometric figure. The rafter system consists of the following main elements:

1. Mauerlat is a wooden beam that acts as a connecting element between the box of the house and its truss system. It is attached to the walls with threaded studs, anchor screws or wire bundles. The size of the cross section of the beam is from 100x100 to 150x150 mm and depends on the size of the building, its number of storeys and the shape of the roof.
2. Rafter leg - a wooden beam measuring 50x150 or 100x150 mm, connected at the top of the roof with a ridge and resting on the Mauerlat with the opposite end. Rafters are the main load-bearing element of the roofing system, which perceives all types of external loads: wind, snow, rain and the own weight of the structure.

   Rafter trusses form the power frame of the roof and determine its geometric shape.

3. Lying - a bar made of wood, laid horizontally with support on an internal load-bearing wall. The size of the bed, as a rule, is equal to the size of the Mauerlat. Supports roof racks.
4. Tightening - an element used in hanging truss systems. Its purpose is to compensate for the tensile forces that occur at the lower ends of the rafter legs.
5. Racks - square bars that transfer part of the load from the rafters to the beds.
6. Struts - structural elements that transfer part of the load from the rafter legs to the puff. Thus, a truss is formed with increased strength characteristics.
7. Counter-lattice - wooden bars ranging in size from 25x50 to 50x50 mm, stuffed onto the upper edge of the rafters. The purpose of the counter-lattice is the formation of a ventilation gap between the crate and the waterproofing film. This element is required when installing a roofing pie in the attic.
8. Lathing - a supporting base for installing the finishing coating of the roof. The lathing is solid or sparse and can be made of 25 mm thick boards, waterproof plywood, OSB sheets and other similar materials. The choice of the design of the crate depends on the characteristics of the finish coating.
9. Skate - a horizontal beam along which opposite slopes intersect.
10. Roof overhang - is a continuation of the rafters at a distance of up to 40 cm from the walls of the building. It protects the walls from getting wet, and also serves to accommodate spotlights, which are an integral part of the ventilation system of the under-roof space. With insufficient length of the rafters, the overhang is formed by additional details for their lengthening - filly.

    The truss system of a gable roof consists of triangular trusses, based on a Mauerlat and a ridge, battens and several auxiliary elements that reinforce the structure.

Calculation of the load on the rafter system of a gable roof

The rafter system experiences certain loads, which can be divided into two types.

1. Permanent loads acting independently of any other factors. Their value is determined by the design of the roofing pie and consists of the weight of waterproofing and vapor barrier films, insulation, additional elements, fasteners and any other elements of the roofing, including the finish. In practice, the average weight of all components of the roof of a house is about 40–45 kg / m 2. More precisely, this value can be calculated by summing the values ​​​​of the specific load of each material used, which can be taken from the lookup tables. When calculating the weight of the roof, it is recommended to lay a safety margin of 10%.

   When calculating the load, the weight of each element of the roofing pie is taken into account

2. Variable loads. These include the effects of wind and snow, depending on their intensity. In fact, the roof of the house is a sail that takes the load from the wind. The force of direct impact on the roof along the normal depends on the angle of inclination of the slope - the smaller it is, the lower the load. At the same time, turbulences appear on the lee slope, and a load appears on the roof with a reverse impact vector. With hurricane winds, the pull-off force can reach 630 kg/m 2 . Variable loads include snow impacts. It should be noted that they also have clearly defined regional indicators.

   Wind loads are a risk factor for roofs as they create large tearing and overturning forces.

Obviously, a careful calculation of the loads from snow and wind, taking into account local climatic conditions, is vital when choosing a roof structure and materials. These loads can be determined from a map compiled on the basis of SNiP 2.01.07–85.

On the map, you can determine the magnitude of the wind and snow load in the construction region

The values ​​of snow and wind load marked on the maps for each region are called standard. In order to obtain the calculated snow load, the standard value must be multiplied by a special coefficient that takes into account the angle of the roof. This ratio is equal to:

• 1 with a slope of less than 25 o ;
• 0.7 at an angle of inclination from 25 to 60 o ;
• 0 for steeper slopes.

The calculated wind load is determined by multiplying the standard value by a factor that takes into account the height of the building and the type of terrain in which construction is underway.

Table: correction factor for calculating wind load (taking into account the height of the building and the type of terrain)

The specific load of the most popular roofing materials can be taken from the following table.

Table: weights of some roof materials

It is possible to take into account the peculiarities of the impact of different types of loads only in the aggregate, therefore, calculations of this nature should be entrusted to an experienced specialist.

Video: calculation of the truss system

Types of gable roof truss systems

According to the principle of the device, truss systems are of two types:

1. Hanging.
2. Layered.

Hanging rafters are used for buildings in which the load-bearing supports are located at a distance of up to 10 meters in the absence of an intermediate wall inside the building box. For other cases, it is necessary to use a layered truss system.

Features of the hanging truss system

The support for the hanging rafters are the outer walls. Since the arch has a connection at the top point, when vertical loads are applied to it, bursting loads are created on the lower supports. To compensate for them, puffs are used - horizontal ligaments between the lower ends of the rafter leg. The result is a rigid power triangle. When constructing an attic room, floor beams are used as puffs. Various design solutions for a hanging truss system are possible:

1. A simple three-hinged arch. It is a triangular structure. In this case, the tightening works only in tension and is not a support. Therefore, it can be replaced with a conventional metal beam. The connection of the cornice assembly in this case is performed by a simple orthogonal tie-in using wooden overlays or metal plates.

   The three-hinged arch is the simplest truss truss design for a gable roof.

2. Three-hinged arch with reinforcement. This scheme was previously used in the construction of industrial buildings, when the span exceeded 6 meters. At the same time, the puff is suspended on a headstock made of wood. The knots are connected using metal parts and are equipped with devices for tension adjustment. The main load in such a system falls on the ridge of the roof. In individual housing construction, such truss systems are not used.

   A three-hinged arch with reinforcement differs from a simple one by the presence of a vertical stiffener (headstock) and the ability to adjust the tension at the joints

3. Hinged arch with raised puff. In this version, the rafter leg is partially unloaded through the roof ridge with a suspension to a raised puff. It rises to a height of at least 2.2 m from the level of the attic floor. Such a system is ideal for arranging an attic room in the under-roof space. The connection of the puff with the rafters is made by a tie-in, as a result of which the connection in the node becomes fixed.

   Hinged arch with raised drawstring ideal for attic roofing

4. A three-hinged arch with a crossbar is used to strengthen the truss system by creating an additional power triangle. The system is used with significant bursting loads. The connection of the crossbar with the rafter must be fixed, otherwise the entire system will not have the necessary rigidity.

   An additional horizontal element (crossbar) gives the system greater resistance to bursting loads

The crossbar, unlike the lower tightening, works in compression, not in tension.

In addition to those listed, other elements are also used to strengthen the roofing skeleton. Very popular are the struts and racks located in the system at the places of the greatest loads on the rafters.

In the most loaded places, roof trusses can be reinforced with struts and struts.

Video: rafter system step by step

Rafter systems of layered type

Laminated rafters are used for buildings with a width of more than 10 meters. They are characterized by the presence of a load-bearing wall inside the building, which is an additional support for the truss system. Layered structures are of several types:

In non-thrust layered systems, the main load from the roof frame is transferred to the Mauerlat

Determining the pitch of the rafters of a gable roof

The task of ensuring sufficient strength of the truss system is solved by selecting the material for the manufacture of its elements and calculating the parameters of their installation. The pitch of the rafters is one of these elements and is selected depending on the weight of the roofing cake. The distance between the support beams is usually set within 0.6–1.5 m. The actual step between the rafters depends on the geometry of the roof and is calculated as follows:

1. The number of rafter legs is determined. To do this, you need to use the ratio n \u003d L / d 1 + 1, where n is the number of rafter legs, L is the length of the roof along the ridge, d 1 is the desired distance between the rafters.
2. The estimated distance between the rafters is calculated, for which the length of the roof along the ridge is divided by the amount obtained in the previous paragraph: d = L / n.

For example, consider a variant with a roof length of 13 m with a preferred distance between rafters of 750 mm (option for a roof with ceramic tiles).

1. The number of rafter legs n \u003d 13000 / 750 +1 \u003d 18.33. Since the number of rafters must be an integer, we round this value up to 19.
2. Rafter pitch d = 13000: 19 = 684 (mm).

Thus, on the roof of our choice, the rafters must be installed in increments of 68.4 mm.

It should be remembered that the result obtained is the distance between the axes of the rafters.

Knots of the truss system of a gable roof

We have already considered the main types of connections in the nodes of the supporting structure of the roof above. But it makes sense to dwell in more detail on auxiliary materials that make it possible to make the truss system more reliable and durable.

It is possible to strengthen the fastening of parts during the installation of the truss system using metal plates and corners of various shapes

Such products are made of galvanized steel up to 1.5 mm thick. They have a different configuration and can be installed on any type of connection.

Photo gallery: types of connections in the nodes of the gable roof truss system

In the ridge part, the rafter legs are usually connected by bolted flat plates. To strengthen the structure of the truss system, it is necessary to select metal plates that correspond to the configuration of the fastening unit Sliding junctions of nodes unload the truss structure Junction points in the truss system can be further reinforced with metal inserts Depending on the type of truss system used, there are different ways of attaching the ridge assembly. On flat joints operating under heavy loads, it is convenient to use nail plates

All docking nodes of the truss system have the function of strengthening the rafters due to the redistribution of loads and strengthening of the bearing elements. So, in the lower part, the rafters are supported on the Mauerlat at a right angle, for which they perform the corresponding inserts.

To strengthen the rafter system, they try to use connections with maximum bearing capacity, for example, inserting the rafter into the Mauerlat at a right angle

In addition, metal mounting plates are used for additional reinforcement in the docking nodes. The same principle is used when installing struts to the rafters. In any case, the mating parts must work "on the stop" and not move during operation.

Any parts must be loaded along their axis

There are three main types of nodes in the truss system:

1. Skate connections. This is the joining of two rafter legs at a given angle along the line of intersection of the slopes. They can be articulated or deaf. The former are used when installing a truss system on timber or log houses, which tend to sag and rise depending on the season for almost the entire period of operation. Blind joints are used in the roof systems of houses made of building stone. In such buildings, a reinforced belt is installed on top of the wall, which takes on lateral loads.
2. Fastening the lower ends of the rafter legs to the Mauerlat. Since they are at an angle to the support beam, a sliding vector is created, directed outward from the building. To compensate for it, a tie-in is made in the Mauerlat, and a heel is made on the rafters. The rafter is inserted into the groove with an emphasis on it and fastened with a nail through the edge of the beam into the Mauerlat. Additional supporting parts made of bars are also used. In cases where the rafter beam must move (on wooden log cabins), sliding fasteners are used. They make it possible to compensate for seasonal changes in the height of the walls.
3. Other nodes. All other parts of the truss systems are essentially thrust elements working in compression, rarely in tension. They are installed by cutting into mating parts to prevent them from moving under load. Such details include crossbars, struts, racks, stops and other similar details.

For a stronger connection, the additional elements mentioned above are used.

Installation of a gable truss system

Currently, the construction market offers services for the manufacture of custom-made roof trusses for specific buildings. It should be noted that this service has a number of advantages:

1. Guaranteed product quality, ensured by the use of special equipment and assembly technologies.
2. Fire safety, as all parts of the trusses are flame retardant treated.
3. Extended service life, which is achieved by antibacterial treatment of products with special compounds.
4. Ease of installation of finished farms.

The only drawback of this method of installing the truss system is the relatively high cost of products.

For self-construction of a gable roof, you can use ready-made roof trusses ordered from professional manufacturers

Assembly of roof trusses on the ground

The assembly of rafters on the ground is used in cases where there is a flat area of ​​sufficient size directly next to the house for the manufacture of trusses. At the same time, not complete trusses are mounted, but rigid structures of three or four parts, which can be lifted to the installation site by the efforts of two or three people. The ascent is made with the help of ropes along the sleds. The advantage of this assembly method is the possibility of using a single template, which ensures high precision in the manufacture of each structural element. A possible option for partial installation of trusses below is as follows:

1. Make a slipway for assembling trusses. It consists of three sites, the distance between which corresponds to the length of the mating parts. They can be assembled from several boards or bars located in the same horizontal plane.

   For the convenience of assembling the truss form on the ground, a free area of ​​​​a certain size and auxiliary elements are required, on which structural details can be placed

2. To assemble the first truss, you need to take two rafter legs and a puff - lower or upper.
3. Having laid out the parts on the slipway, place them in accordance with the truss drawing and fasten them with nails. Check the truss blank for compliance with the dimensions specified in the technical documentation. If necessary, correct the location of the components.
4. Perform the final fixation of parts in the truss nodes using additional mounting plates. Nail plates can be installed using a power clamp, using additional thick steel pads under its jaws.

   Power clamp allows you to pre-pull the nail plates, and then fix them in any convenient way

5. Lay the details of the second truss on top of the first and fix with clamps, exactly following the contours of the lower truss, which plays the role of a template. After assembling the second farm, remove it to the side.
6. Make the required number of farms, repeating the operations from the previous paragraph. Thus, full compliance of all manufactured trusses is ensured.

   When manufacturing roof trusses according to one template, they will exactly repeat the size and shape of each other

Installation of the truss system at the installation site is carried out as follows:

1. The first two farms rise to the roof. To do this, you can use an inclined flooring of several bars and fairly strong ropes.
2. Gable trusses are installed first at the ends of the roof. They need to be set strictly vertically and fixed to the Mauerlat with temporary jibs.

   First you need to install gable trusses

3. Between the gable trusses, a construction cord is stretched perpendicular to the location of the rafter legs.
4. Each subsequent truss is installed in compliance with the previously calculated rafter pitch.

   In order for all truss trusses to be installed evenly, twine is stretched between the extreme structures

5. After the installation of the last truss, the entire structure of the truss system is reinforced with girders, after which the temporary fasteners are dismantled.
6. Next, the rest of the structural elements are mounted - jibs, ridge beams, beds, racks, etc., provided for in the design of the truss system.

Additional strength to the roof is given by the crate, stuffed last.

Assembly of rafter legs directly at the installation site

Local assembly of rafters is used on small roofs. At the same time, blanks are fed up, from which the necessary details are cut. Installation is carried out from the bottom up, starting with the installation of the rafter legs. The horizontal level of the truss system is controlled by tensioned cords, and the verticality of the truss assembly is controlled by a plumb line. The installation order is the same: gable trusses are mounted first, then the rest in any convenient order.

The assembly of the rafter system directly on the roof begins with the installation of racks and a ridge run, on which the rafters are laid

Accurately fulfilling the requirements of the drawings, you can mount the truss system yourself. It is almost impossible to do this alone, so the participation of one or two assistants is mandatory.

Video: do-it-yourself installation of rafters

When assembling a truss frame for a gable roof, it is important to follow certain rules:

1. All wood used for the installation of the truss system must be treated with antiseptic and fire-fighting compounds.
2. When working with hand-held power tools, the safety requirements specified in the instructions must be observed.
3. Installation of nail plates cannot be done by hammering, this leads to their deformation. A clamping tool must be used during installation.
4. A layer of waterproofing must be laid under the Mauerlat. Traditionally, ruberoid is used for this.
5. When installing the truss system, you need to use fasteners with a protective coating.
6. Installation of the truss system should be carried out in dry calm weather.

Video: gable roof for metal tiles

Like any roofing system, a gable roof requires careful and responsible attitude. Mistakes in the construction of such roofs are usually expensive. Not only the careful selection of materials is important, but also their competent use. However, most of the work can be done independently. I wish you success!

The truss system of any object is equivalent to the value of the load-bearing structural elements of the house. The roof plays the role of a node under which the stiffening ribs of the building are assembled. Accordingly, when installing the roof with your own hands, it is required to give the maximum value to all structural units, even when using a simple option - gable.

Advantages of gable roofs

There are a lot of options for pitched truss systems. Among them, simple symmetrical is especially popular. Why? Here are her virtues:

• On the basis of a gable roof, variations are created to reflect the special architecture of the building.
• Simple calculations, easy to understand.
• The one-piece design creates favorable conditions for the dryness of the internal space and the unhindered flow of water, snow and ice.
• The maintainability, strength and durability of a gable roof are much higher than other options.

Depending on the size, homeowners always have the opportunity to equip the under-roof space, make it a full-fledged floor or attic. In a word, a gable roof is the right and profitable solution for any object, whether it is a residential building, a summer house or a bathhouse.

Elements of the truss system

Depending on the type of roof, structural elements vary. Without knowledge of the appointments of each, it is impossible to arrange a reliable coverage at home. Let's analyze in detail:

Mauerlat

The basis of the truss system. It is a beam with a section of at least 150 mm, or an I-beam channel, if the roof structure is metal. It is located on the bearing walls of the object. Its purpose is to distribute the load of the system evenly throughout the structure of the house.

Rafter leg

Structural basic unit of the system. Together with others, it forms a truss system - strengthening the strength of the entire roof. It is made of a wooden beam, which is not inferior in cross section to Mauerlat or profile pipes.

Rafter rack

Vertical bar or pipes. Depending on the variant of the gable roof, the pillars can be located in the center and / or on the sides. They take part of the weight of the entire truss system, which is why the cross section is 150 mm.

Rafter girders

Horizontal beams laid on racks and under the ridge to support the rafter legs. They provide structural rigidity and relieve stress on trusses.

Puffs and braces

Connecting beam for rafters. The action is similar - relieving the stress of a beam or metal and making the structure rigid.

lying down

Mounting support for racks and struts. To securely connect these two elements, you need a large cross-section beam - 150 mm or a thick-walled pipe of impressive diameter.

Lathing beam

Elements laid perpendicular to the rafters. Serve to install the selected roofing and create a multilayer protective cake. The cross section is small - 40–50 mm.

If the planned roof structure is made of wooden beams, you should carefully consider the quality of the wood upon purchase - the beam should not have knots interspersed, be made of soft wood.

Also, wood must have natural moisture, otherwise it will begin to dry right in the system structure, cracking, deforming the roof model, depriving it of reliability and safety.

Calculation of the truss system

A gable roof is a complex structure. The project takes into account many factors - natural nuances, wind, constant and variable loads. It is extremely difficult to make calculations on your own, without special knowledge about the climate of the area, the characteristics of the material for the manufacture of the system, and the nuances of pressure distribution.

Ideally, the calculations are at the mercy of professionals, you can independently choose only the material for coating - the following parameter depends on its type:

Tilt angle

The minimum angle of inclination of the roof relative to the parallel of the earth is 5 degrees. However, its dependence comes from the chosen roofing material. In this capacity, traditional slate, profiled sheet, flexible and metal tiles are used.

They are guided by the following rule: the steeper the slope, the more textured the roof can be.
From 5 degrees for laying rolled protective insulation of the roof. The number of layers matters - up to 15 degrees three-layer coatings, above - two- and single-layer coatings.

• From 6 - ondulin.
• From 11 - slate.
• From 12 - corrugated board.
• From 14 to 20 - metal tiles.
• From 15 to 45 - soft roof.

Thus, the resulting precipitation - snow, water - will not linger on the surface, although complete cleaning requires one's own efforts or the involvement of specialists for the installation of the Anti-Ice system.

Determining the parameters of the rafters - step, length, section

The rarer the step, the more impressive the cross-section of the beam or the diameter of the pipes should be. As a rule, for load-bearing structures, this parameter is at least 150 mm, 100 mm - for country houses and related construction - gazebos, bathhouses, outbuildings.

Next, you need to set the number of rafters per slope: its length is divided by the installation step, which is from 60 to 100 cm + 1 extreme leg. Multiplying the result by 2 gives the total. Depending on the section of the beam, the amount of rafter legs and the installation step vary.

The length of the rafters is simply calculated if the school knowledge about the right triangle is left in the luggage. The rafter leg is equal to the hypotenuse of the resulting figure. The calculation is as follows: A² + B² = C², where - A is the height of the roof, B is half the length of the pediment, C is the length of the rafter leg. To the resulting value is always added from 30 to 70 cm for cornice overhangs.

Types of truss systems

Before getting down to work, it is important to choose a truss system option for a gable roof. There are few of them, each has its own advantages and disadvantages:

hanging

Suitable only for a standard roof width of 6 m, respectively, this is the length of the rafter leg. Fastening occurs by fixing the ends to the ridge run and the bearing wall. Be sure to install a puff that levels the stress and pressure of the structure.

In addition, they will play the role of load-bearing beams. Without them, the structure will disperse under weight. The advantages of the option are in the absolute dryness of the roof surface during the off-season, and in less deformation at the time of shrinkage.

Layered

The option is suitable for any roof width. Reliability and stability is ensured by fixing the bed to the Mauerlat. Thus, the pressure is leveled by the rack, which reduces the tension in the rafter legs. The advantage of the system is simplicity, but the design requires large investments - additional lumber is required to equip the beds.

hybrid

These systems are typical for multi-pitched roofs, where transitions are accompanied by numerous reinforcements, beams, posts, beds, slopes and other elements for the stability of the entire structure. The device is expensive and complicated, so only a professional should deal with the project and construction. At least curate it.

Do-it-yourself installation of a gable roof

So, when the option of the truss system is selected, lumber is purchased, a roof project is drawn up, you can get to work. You cannot deviate from the sequence of steps. This threatens to delay installation and loss of structural reliability.

Mauerlat mount

If the length of the beam for installing the Mauerlat is insufficient, an extension is made. Using the half-tree cutting method, the ends are connected. Additional fasteners are anchor bolts. Do not use self-tapping screws, dowels or nails - they are unreliable. Mounting to the wall is as follows:

• There must be a margin of at least 5 cm from the edge.
• Holes are drilled along the wall for inserting fasteners. Similar actions are carried out with a bar.
• Mauerlat is attached to the edge with steel studs. The fastening step is more often 2 times than the distance between the rafter legs. Subsequently, before installing the main units, they are guided by metal marks.

Important - before laying the Mauerlat, the edge of the wall is protected with waterproofing. Spread one layer even if the house is made of wood.

Making and fixing rafters

Roof trusses are convenient in that they can be assembled on the ground into a finished structure and moved to the roof. This will reduce installation time, however, the model is heavy and lifting equipment will be required, which, of course, will increase the cost of the project.

For budget construction, another method is suitable:

• At the bottom and top of the rafter legs, a gash is made to attach to the Mauerlat and the ridge run. This must be done separately with each unit, after lifting the wood up.
• Places for fixing are marked on the Mauerlat and a ridge run is installed: racks are installed along the gables, on which a beam is placed. If the length is not enough, it is increased, but in a different way, unlike the Mauerlat - a board is screwed to the junction from both sides.
• Depending on the chosen model of the truss system - layered, hanging - they make cuts in the ridge beam, Mauerlat or drill holes in them for fasteners.
• Next, begin the installation of rafter legs from opposite ends of the roof, gradually moving towards the middle. Between the corners of the extreme trusses, it is not bad to stretch the cord to exactly match the entire horizontal part.
• Between themselves, the rafter legs are connected by puffs and struts. Under the ridge part, at the angle formed by the rafters, wooden linings are stuffed, and the ends themselves are tightened with bolts.

More recently, professional builders have begun to use sliding fasteners for roof installation. Metal plates securely hold the bearing elements and at the same time move due to shrinkage. This cancels out its effects.

The work of fixing the rafters is hard and long. You should calculate the time in advance - you can not leave the roof unfinished during the rainy season, otherwise the rigidity of the structure will be lost in the future due to absorbed moisture.

Gables and framing

The side parts of the roof - gables, are made in the form of ready-made shields from boards and are completely installed at the top. Difficulties should not arise - it is only important to carefully file them at the required angle. It is necessary to fasten the crate only after the final appearance of the roofing is known. For example:

• Under the corrugated board, the step of the crate beam will be 440 mm.
• The metal tile is fastened to the crate in increments of 350 mm.
• A soft roof needs a solid plywood coating.

It is important to note the places for the passage of the chimney - the crate should not come into contact with a brick or metal surface. The distance to the hot unit is at least 15 cm. Before installing the lathing, the finished roof is covered with waterproofing with allowances extending beyond the edges of the walls. Then the beam is mounted.

If it is decided to make a warming cake from above, then first the vapor barrier is strengthened from the inside, then the selected material is put into the boxes formed by the rafters. Next, waterproofing and wind protection.

Then it is required to re-mark the contours of the rafter legs with a beam 20 * 20 and then fill a new layer of the crate, along which the roofing material will be laid - the formation of ventilation ducts. This method will save the capacity of the under-roof space if the owners are going to use it for a specific purpose.

Roofing material flooring

Regardless of the type of roofing raw material, installation starts from the edges of the roof and leads it up, laying one unit on top of the other. Thus, rain moisture will not get under the material.

The method of fastening depends on the type of material - soft tiles or tiles with a bitumen or polymer base are fused. Solid profiled sheets - ondulin, metal tiles - are fixed in pre-drilled holes to the crate, using rubber pads to seal and preserve the anti-corrosion layer.

As a result: the description of the installation of the truss system and the roof is easy only on the screen or paper. In reality, the process is complex and multifaceted. Therefore, if knowledge is not enough, it is better to invite professionals to work - their work is always guaranteed.