Nodes of wooden roofs of residential rural buildings. Wooden roof: joints, assembly technology. Wooden roof - ecology, economy and reliability

The roof is one of the main elements of a residential building. Both the comfort inside the house and the service life of the structure depend on how well the device is made. The roof plays an especially important role in multi-storey residential buildings, the total area of ​​which exceeds several hundred square meters.

What does the roof of a house consist of?

The roof of the house is the uppermost part of it, used to protect the load-bearing elements and the living space of the building from atmospheric precipitation. In addition, it is a thermal insulation barrier that reduces heat outflow from residential premises and protects the structure of the building from overheating.

The roof not only protects the under-roof space from precipitation, but also helps to keep warm in living quarters.

Depending on the functional belonging of the building and its design, the roof can have a different look. The design and appearance of the roof determines its ability to drain snow and rainwater from its surface. The space under the roof frame is often used as a living or utility room.

Any roof has a typical design, which is determined by the technology and temperature regime in the region where the structure is being erected. To better understand this topic, consider the structural elements of the roof in more detail.

Roof frame

The roof frame is a load-bearing and supporting element responsible for its strength characteristics. The quality of the frame directly affects the service life of not only the roof itself, but also the structure as a whole.

As a supporting structure for the roof in private houses, a rafter system of wooden beams is usually built

Depending on the design, the roof frame may look like this:

• rafter system is the most common type of roof frame, most often used for the construction of roofs of utility and residential buildings from timber, bricks and foam blocks. It is subdivided into hanging and layered structures. The former are used in buildings where only external walls are load-bearing, and the latter are used in houses with internal load-bearing partitions, which can be used as additional supports;
• support system of steel beams - used for the construction of roofs over industrial buildings. Unlike wood, metal allows you to create longer, and most importantly, solid beams without mates along the length. This, in turn, significantly increases the load-bearing capacity of the roof structure. Metal is a non-combustible material, which makes the roof safer and more durable;
• flat concrete frame - represents reinforced concrete slabs laid on top of load-bearing walls at a certain angle. Most often used to create roofs over small public buildings and storage facilities.

For the implementation of any special project, various types of frames can be combined or used in a modified form. For example, roof truss systems are often erected from wood and metal at the same time, which in one place of the structure makes the roof more durable and reliable, and in the other it does not make the load-bearing partitions heavier, thereby reducing the overall load on the foundation. This option can be used when one part of the house is located on a slope. The lightening of the roof structure will avoid unnecessary stress on the columnar or pile foundation, which is most often used in such cases.

Video: gable roof frame for metal tiles

Roofing cake

Roofing pie is a technology for laying roofing, steam and thermal insulation in a certain sequence. Correct alternating laying ensures that each technological layer fulfills its strictly defined function.

For example, if the waterproofing material is laid incorrectly (under the thermal insulation), then moisture will enter the insulation, which will inevitably cause its damage and loss of the characteristics declared by the manufacturer.

All layers of the roofing cake must be laid in a strictly defined sequence so that each coating can perform its assigned functions.

A typical roofing cake consists of the following technological layers:

• roofing material - a cladding that is responsible for the appearance of the front surface of the roof and protects the sheathing and underlying layers of the roofing cake from water, dirt and foreign objects;
• lathing - a supporting structure necessary for fastening the roofing material. Depending on the type of topcoat used, the crate can be solid or sparse;
• waterproofing is a mechanically durable waterproof material that protects the insulation from getting wet. For this purpose, bitumen roll coatings, anti-condensation membranes or liquid mastics can be used. The specific method of waterproofing is selected based on the type of roof and insulation;
• thermal insulation - basalt roll or slab insulation, polystyrene, expanded polystyrene, etc. The thermal insulation material must have a low coefficient of thermal conductivity, which guarantees long-term maintenance of the required climatic regime in the house at any time of the year;
• vapor barrier - a multilayer membrane that protects the insulation and other elements of the roofing cake from the penetration of warm humid air from the interior.

The sequence of laying the technological layers of the roofing cake is determined by the type of roof to be installed and the materials used for this. The most common option is when waterproofing is laid under the roofing, then a layer of heat-insulating material goes, and a vapor barrier membrane is mounted under it.

The main nodes of the roof

The junctions of the roof to the wall, if the building has a complex shape, as well as the places where the roofing cake and the external facing cover are attached to the outrigger parapet, are no less important than the roof structure itself.

The integrity and durability of the structure being erected depends on the quality of their performance, since the use of low-quality materials or non-compliance with the connection technology can cause moisture and precipitation to penetrate under the roofing.

Roof abutment nodes

The place or node of the abutment of the roof to the wall is a connecting seam, which is processed using waterproofing and protective materials. The junctions are the most vulnerable place of any roof, since wet debris constantly accumulates at the junctions of its elements.

If the junction is poorly insulated, moisture quickly gets under the protective material and the roof covering. The constant absorption of moisture into the insulation will necessarily lead to the loss of its technological qualities.

All places where the roof adjoins the structural elements of the building must be carefully treated with waterproofing materials to prevent moisture from entering the under-roof space

In addition, the junctions are subject to temperature deformations due to freezing and thawing of water - this increases the risk of leaks. In order to avoid problems during the operation of the roof, the adjoining insulation technology is thought out in advance. The calculation takes into account both the temperature regime in the region where the structure is being erected, and the average rainfall throughout the year.

Depending on the type of roofing, the junction nodes are arranged in different ways:

• metal roof - the joints are made with a small gap, necessary for ventilation of the roofing cake. A metal strip or a galvanized steel apron is used as a protective element. The apron is attached directly to the adjoining wall at a height of 200 mm or more. Before installing it, the strobe in the wall is treated with a frost-resistant sealant;
• various types of shingles - the junction of the wall and the roof covering is protected with corrugated aluminum tape. Due to its small thickness, the tape precisely follows the profile of the roof covering. Hot bitumen mastic is used to seal the seam, which is poured directly along the seam line;
• bitumen roll materials - the junction can be made using various technologies. The most common way is to lay the floor covering with an overlap on a vertical surface. In this case, the material is pressed by a rail, which is pre-treated with a sealant. The amount of overlap, as a rule, is at least 20 cm.

Cornice knot

The cornice covers and protects the lower part of the roof, the roofing cake, the rafter system and other elements from moisture. In fact, the finishing of the cornice assembly directly affects the service life of the Mauerlat and the roof truss system, since with poorly executed cladding, moisture flowing down the roof covering can get into the under-roof space.

To protect against moisture penetration into the under-roof space, special metal strips are installed on the eaves overhangs - droppers and ventilation tapes

For the device of the eaves unit of the pitched roof, the following sequence of laying the protective materials is applied:

1. Roof covering.
2. Counter lattice.
3. Roof lathing.
4. Waterproofing membrane.
5. Dropper.
6. Bracket for fixing the gutter.
7. Gutter.
8. Cornice strip.
9. Overhang aero element.
10. Ventilation tape.
11. Double-sided adhesive tape.

The drip bar protects the frontal board from condensation flowing down the waterproofing film, and the cornice bar prevents moisture and precipitation from entering the under-roof space. The overhang aero element serves to create a ventilation gap and protect against birds and large insects from penetrating under the roof.

Gable knot

The gable is the end section of the roof, bounded by the roof slope and the cornice. It protects the roof from moisture penetration, and also plays the role of a decorative element.

The pediment completes the roof, but it is not a required attribute, since in some types of structures the roof is limited only by the cornice.

Most often, gables are arranged on pitched roofs, when various types of tiles, profiled sheets or soft bituminous coatings will be used as roofing.

From the side of the gable, the under-roof space is protected by a wind board, and then by a gable strip laid on top of the waterproofing layer

The sequence of laying materials when arranging a pediment unit is as follows (from the outer edge to the under-roof space):

• gable plank laid on top of the roof covering;
• waterproofing material;
• wind board;
• crate;
• rafter.

When attaching the gable slats, the technology described in the instructions for the roofing should be followed. They are usually mounted from the bottom up from the eaves to the ridge. When using multiple planks, the overlap should be at least 10 cm.

The device of the valley

Endova is the inner corner of the roof formed at the junction of two slopes. In fact, when erecting multi-pitched roofs, the valley is a key structural unit, since precipitation will flow down it. End roofing always experiences increased loads, therefore, its device must be carried out especially carefully, in full accordance with the technological requirements established by the manufacturer of the used roofing material.

Devices of an end node for a pitched roof are performed using special additional elements that are mounted on a solid crate

A typical version of a valley unit for a metal roof is represented by the following elements:

• upper valley;
• sealing material;
• roof covering;
• bottom valley;
• solid crate;
• waterproofing membrane;
• roof truss system.

Endova is usually laid on a solid crate, which is mounted on both sides of the junction of the slopes. When using metal coatings (corrugated board, metal tiles, seam roofs), the main protective element is the lower valley. It fits under the roofing material and serves as a kind of gutter through which moisture flows into the drainage system. In this case, the upper valley is more of a decorative element that covers the entire structural unit and protects it from birds and foreign objects.

Ridge knot

The ridge of the roof is the upper horizontal edge formed by the conjugation of two ramps. The ridge strip or tile protects the junction of the rafters, thermal insulation and battens from moisture and is installed last. Different ridge elements are used depending on the roof covering.

The device of the ridge knot is carried out last, when the roof covering is laid.

For example, the device of the ridge knot for a soft roof looks like this (from top to bottom):

• ridge soft tile;
• roof covering;
• lining carpet;
• roof sheathing.

In some cases, a ridge block 40x40 or 50x50 mm is nailed along the edge, on which the underlay carpet is laid. If you plan to install the roofing yourself, read the instructions for the material - it must contain a diagram of the device of all the main roof assemblies.

Parapets around the perimeter of the roof

A roof parapet is a fencing structure mounted around its perimeter. Parapets are usually mounted on flat roofs, but quite often they can also be seen on pitched roofs, especially in the residential multi-apartment sector. The main purpose of the parapet is to ensure the safety of the person on the roof. Sometimes such designs are used as a decorative element.

The installation of parapets (SNiP II-26–76) is mandatory for buildings whose height to the eaves of the roof is more than 10 m, and the slope angle of the slope does not exceed 12 degrees. On steeper roofs, the installation of fences is carried out already at a height of 7 m.

If we consider low-rise private housing, then the installation of parapets is relevant only for houses with a flat roof. For gable or hip roofs, the installation of parapets is optional. But it should be borne in mind that if it is planned to carry out annual maintenance of the roofing on pitched roofs, then the safety measures must be appropriate.

In private construction, parapets must be arranged only on flat roofs.

The following materials are used for the manufacture of parapets:

• reinforced concrete blocks;
• brick and foam blocks;
• galvanized metal.

According to SNiP, the height of the parapets should be at least 45 cm. The optimal height is chosen based on the architectural features of the structure and the personal preferences of the owner of the house.

The junction of the roofing pie to the parapet is performed using hydro- and heat-insulating materials. At the junction of the parapet and the roof, a transitional board made of mineralized insulation is laid. To fix the insulation, a special cold mastic is used. The waterproofing is installed with an overlap of 20-25 cm on a vertical surface.

To protect the parapet, a similar waterproofing material is used, which is fixed with an overlap on the previously laid canvas coming from the roof side. A U-shaped galvanized steel box is also installed on top of the insulation.

Complementary roof elements

Complementary roofing elements are products designed to connect various units and parts of the roofing. In addition, they provide additional functionality, as well as improve the appearance of the front surface of the roof and the roof in general.

Various additional elements allow to protect the roof structure from weather influences, preventing the penetration of moisture, dust and debris into the under-roof space. It should be understood that depending on the roof structure, the number and need for the use of additional elements may vary.

For a metal roof, a wide range of additional elements is used to protect its structural units from moisture and debris penetration and give the entire building a finished look

For example, typical additional elements used in the construction of a pitched roof include:

• ridge and valleys;
• junction elements;
• strips for cornices;
• end strips;
• corner strips;
• snow barriers;
• adapters;
• gutters.

Before choosing additional elements, you should carefully study the roof project and, on its basis, calculate the amount of material required. It is not recommended to save on additional elements, since the safety of the roof structure and roofing pie at the junctions, on the ridge and drains depends on their quality.

Video: roof device - insulation, ventilation, board selection

Construction of various types of roofing

The structure of the roofing and the roofing cake varies greatly depending on the type of construction. This is due both to the design features of the roof being erected, and to the features of the materials used for its construction. For a more detailed description, consider the most common types of roofing in more detail.

Warm and cold roof

Warm roofing is a generalized concept that denotes an insulated roof structure. That is, any type of roof can be warm or cold, depending on whether the appropriate hydro- and heat-insulating materials were used during their installation.

If, when erecting a roof, the standard roofing pie is completely mounted, then it is called warm

If we talk about the private sector, then in buildings that will be used for year-round living, it is recommended to carry out insulation for any type of roof. The most common roof structure for private houses is a gable structure, so we will consider the construction of a roofing pie using its example. The main elements of a warm roof roofing cake are:

The number of layers of insulation is selected individually for each house project. This takes into account both the size of the structure itself and the possibility of creating a residential attic space, as well as the temperature regime in the region where construction work is carried out.

Sometimes, if the owner of the house, for example, decided to save on roof construction or the attic space will not be used as a living space, the roofing can be done without laying thermal insulation material and vapor barrier. This roof is called cold. The role of the vapor-permeable material will be played by a moisture-resistant vapor barrier membrane. Cold roofs are commonly found in seasonal homes and outbuildings.

Metal coated pitched roof

A metal roof is usually a pitched structure with a wooden rafter system. The type of rafter system is selected based on the location of the load-bearing walls of the building. The use of metal as a roof covering influences the technology of the construction of the roofing cake of such a roof.

The most popular roofing material for private residential buildings is metal.

For the device of a metal pitched roof, the following materials are used:

• additional elements - a metal ridge, side wind strips, a gutter and a gutter strip, a gutter and other elements installed after the installation of a metal covering;
• roof covering - flat sheet material (folded roof), profiled sheet, metal tile or other painted metal materials;
• lathing - edged boards or metal profile elements, fixed in increments of 25-30 cm;
• rafter system - can be made either from a thick edged board or timber, or from metal. In private construction, the first option is most popular due to its availability, ease of installation and lower weight.

The rest of the technological layers of the metal roofing cake are identical to the option described in the section above. It should be noted that the metal coating is especially prone to the formation of condensation on the inner surface, where, despite the presence of special protection, humid air from the house still penetrates. Therefore, the device of all the ventilation gaps provided by the technology when using a metal roof is strictly necessary.

Waterproofing is made of a moisture-resistant membrane, which is fixed on the roof truss system, and any plate insulation with a thickness of 5 cm or more is used as thermal insulation.

Video: organization of waterproofing for a metal roof

Pyramidal roof

A pyramidal or hipped roof is a pitched structure, where each of the four slopes is equal in area, and there is a square at the base of the roof. In fact, each of the four rays is an isosceles triangle.

In some cases, a pyramidal roof is understood as a structure with any number of slopes - the main thing is that they are the same size. Such roofs look very harmonious and do not look like other types of roofs.

In terms of its structure, the pyramidal roof is made according to the traditional scheme with rafter elements, although it has some features in comparison with the classic gable version.

The rafter system of the pyramidal roof has a number of structural differences from the device of the standard gable roof

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

• slant rafters - diagonal beams located at the corners of the structure. They are made from a bar or a double thick board;
• Mauerlat - a lower horizontal bar required to support and fix the diagonal rafters;
• rafter legs (rafters) - support bars attached to diagonal rafters. Provide increased strength and rigidity of the structure;
• struts - vertical struts used as supports for rafter legs;
• crossbars - horizontal beams that are mounted on the top of the diagonal rafters. Increase the strength and wind resistance of the roof;
• beds - horizontal elements at the base of the structure, to which the racks are attached.

The general structure of the pyramidal roofing pie is not much different from the classic version.

1. The filing of the rafter system is done with a rough board.
2. The vapor barrier membrane is folded out and fixed.
3. Insulation of the required thickness is laid on it.

   Insulation plates must be laid so that they enter the space between the rafters with a noticeable interference and do not leave gaps for cold air to enter

4. Waterproofing material is laid.
5. A counter-lattice is mounted, additionally fixing the waterproofing layer.

   Bars of counter-lattice, laid along the rafters, fix the waterproofing film and form the necessary ventilation gap, and the boards of the longitudinal lathing serve to fasten the roofing

6. The longitudinal crate is laid.
7. Roofing is being installed.

   The hipped roof looks very harmonious and gives the house the appearance of a fabulous terem

SIP-panel roof

SIP-panel (from the English. Structural Insulated Panel) is a building material in the form of a plate, consisting of two outer plates of solid material, between which there is a layer of insulation. On the one hand, the sheath of the SIP panel is made of OSB, on the other, from a sheet of corrugated board or also from OSB. Metallic-coated panels are used as an independent roof covering, OSB products are used as a continuous decking under a soft roof.

As a rule, foam or expanded polystyrene of a certain density is used as a heat insulator. Sometimes polyurethane foam is pumped into the space between the slabs or polypropylene is mounted. Previously, the panels were used only as a material for the construction of the frame of buildings, but now they are successfully used for the construction of roofs.

Unlike traditional materials, installation of SIP panels does not require creating a massive frame

A typical device for a gable roof made of SIP panels for a soft roof is the following sequence of elements:

• harness - made of a wooden bar with a comb. The size of the timber depends on the size of the panel groove;
• ridge and end rafters - a beam of a similar size is used for manufacturing. For a skate, you can take a board with a thickness of 5 cm;
• mauerlat - made of timber from 100x100 to 200x200, depending on the size of the house and the thickness of the walls. It is mounted on the upper ends of the walls to provide support for attaching the piping.

Each SIP-panel is laid on the rafters and the nearest horizontal girders. Further, it is adjusted and processed with a special adhesive mass or frost-resistant polyurethane foam. At the end, a trim of a suitable size is mounted in the groove of the panel. In this case, the harness is also fixed to the Mauerlat and the ridge.

Video: installation of a roof from SIP panels

Semicircular roof

The semicircular roof is a "curved" structure with smooth vault lines. For its construction, a rafter system based on arcuate slats is used.

For their manufacture, a board of the highest or first grade is used, which is steamed up to 100 degrees. Due to the absorption of a large amount of moisture, the wood becomes elastic. Special shapes are used to bend the workpieces. After shaping, the workpieces are glued and sent for drying.

As a result, the customer purchases a certain set of material, sufficient for the manufacture of a roof according to a pre-drawn up project. The assembly scheme is as close as possible to the technology that can be found when installing metal domed roofs.

For the construction of a semicircular roof, special rafters are used, made for a specific project

The semicircular roof consists of the following elements:

• Mauerlat - lower support beams required to fix the elements of the rafter system;
• lamellas - elements of small length, having an arched shape. They are assembled into a frame using stringers;
• stringers - horizontal elements that are attached between the lamellas when assembling the frame;
• partitions - horizontal beams fixed from the end of the roof. Provide rigidity and strength to the structure.

To assemble the rafter system of a semicircular roof, galvanized fastening strips and self-tapping screws are used. The size of the fasteners is selected for the specific size of the lamellas. The sequence of laying insulation and insulation is completely identical to that described above.

Expansion joint device

The expansion joint located on the surface of the roof covering is designed to compensate for the thermal expansion of the facing material. In addition, it reduces the resulting stresses due to movement or shrinkage of the roof structure.

The layout of the expansion joint device depends on the size and design of the building. In the case of residential buildings, the arrangement of the seam is necessary when the roof of one building is adjacent to the wall of another, when materials with different degrees of linear expansion are adjacent, as well as in places where there is a sharp temperature drop inside the room.

For the device of the expansion joint on a flat roof, vapor barrier, mineral insulation and bitumen roll coating are used

In private construction, expansion joints are installed on flat soft or pitched roofs covered with bitumen roll coatings. They consist of several components:

• vapor barrier - laid without joints under the expansion joint. It is better to use a moisture resistant vapor barrier membrane;
• the space in the place of the rupture - in the place where the expansion joint passes, a compressible non-combustible heat-insulating material is laid. Compressibility is determined according to GOST 17177;
• expansion joint - a mineral heat-insulating material is laid over the break point so that it overlaps the joint by 15 cm on each side. Hot mastic is used for fixation;
• heat insulator over the seam - for additional stress compensation, a mineral insulation is laid over the seam, rolled into a tube of Ø50–70 mm.

To protect the expansion joint, the roof covering is laid with small sheets covering the joint by 30-50 cm on each side. More detailed technology for arranging expansion joints should be checked with the manufacturers of the roofing material that is planned for purchase.

Roof exit device

During operation, the roof and additional elements of the roof require periodic inspection, which allows you to prevent emerging or eliminate problems that have already arisen. For this, it is advisable to equip the roof with a special exit.

The type of device used depends not only on the slope of the roof, but also on the size of the attic. Some types of structures are simply inconvenient to keep in a small space.

Transparent roof hatches are also great sources of natural light

To exit to the roof, the following methods are used:

• roof hatches are ready-made products that are mounted in pre-prepared holes in the roofing cake. They represent a steel or plastic box with a fixed monolithic or transparent hatch. Access to the roof is carried out by means of a stepladder or a ladder;
• hatches with a folding ladder are devices combined with an attic ladder that folds into a specially designated space. As a rule, in the folded version, this type of hatches is no different from the previous one;
• a dormer window is a compromise option when the window is used not only to illuminate the under-roof space, but also to exit to the roof. It is highly desirable that roof drains be provided on the roof surface;
• external staircase - a metal welded or wooden staircase that is attached to the wall of the house as needed. If desired, it can be fixed on the surface of the wall, but not all owners of private houses will like this.

Installation of roof hatches is not particularly difficult and is carried out in accordance with the instructions attached to them. Usually it is a steel box, which is fixed to the rafter system with self-tapping screws. In some cases, the box is mounted directly on the foam.

Roofing is a vast topic that requires careful study of technology. Especially when it comes to multi-slope roofs that have a large number of slope abutments. If you decide to do the installation of the roof yourself, carefully study all the available information and only then proceed with the work.

When designing any residential building, architects pay special attention to the roof, since it performs not one, but several functions at once, depending on its design features. It must be said that not all future homeowners are satisfied with the usual gable roof, although it can be called the most reliable, since it has only two pitched planes and one joint between them. Many are attracted by more complex structures that add special appeal and originality to the structure. Other, more practical homeowners prefer skylights that can serve as both a roof and a second floor at the same time.

The basis of any roof is an individual rafter system, which has its own design features. It will be much easier to make the choice of the desired roof frame if you figure out in advance which types and diagrams of rafter systems used in construction practice. After receiving such information, it will become more clear how complex such structures are in installation. This is especially important to know if the roof frame is supposed to be erected independently.

The main functional tasks of roof systems

When arranging pitched roof structures, the rafter system is a frame for covering and for holding the materials of the "roofing pie". With the correct installation of the frame structure, the necessary conditions will be created for the correct and non-insulated types of roofs that protect the walls and the interior of the house from various atmospheric influences.

The roof structure is also always the final architectural element of the exterior design of the building, supporting its stylistic direction with its appearance. Nevertheless, the design features of the rafter systems must first of all meet the strength and reliability requirements that the roof must meet, and only then - the aesthetic criteria.

The frame of the rafter system forms the configuration and angle of inclination of the roof. These parameters largely depend on natural factors specific to a particular region, as well as on the desire and capabilities of the homeowner:

• The amount of precipitation in different periods of the year.
• The direction and average speed of the wind in the area where the building will be erected.
• Plans for the use of space under the roof - arranging residential or non-residential premises in it, or using it only as an air gap for thermal insulation of the premises below.
• A type of planned roofing material.
• The financial capabilities of the homeowner.

Atmospheric precipitation and the strength of wind flows give a very sensitive load on the roof structure. For example, in regions with heavy snowfalls, you should not choose a rafter system with a small angle of inclination of the slopes, since the snow masses will linger on their surface, which can lead to deformation of the frame or roofing or to leaks.

If the area where the construction will be carried out is famous for its winds, then it is better to choose a structure with a slight slope of the slope so that the sudden gusts that occur do not tear off individual elements of the roof and roof.

Basic elements of the roof structure

Details and assemblies of rafter systems

Depending on the type of truss system chosen, the structural elements used can vary significantly, however, there are details that are present in both simple and complex roof systems.

The main elements of the rafter system of a pitched roof include:

• Rafter legs that form the roof slopes.
• - a wooden beam, fixed on the walls of the house and serving to fix the lower part of the rafter legs on it.

• The ridge is the joint of the frames of the two slopes. It is usually the highest horizontal line of the roof and serves as the support on which the rafters are anchored. The ridge can be formed by rafters, fastened together at a certain angle, or fixed on the ridge board (run).
• The lathing is slats or beams mounted on rafters with a certain pitch and serving as the basis for the flooring of the selected roofing material.
• Retaining elements, which include benches, girders, racks, struts, ties and other parts, serve to increase the rigidity of the rafter legs, support the ridge, and tie individual parts into a common structure.

In addition to the above-mentioned structural details, it can include other elements, the functions of which are aimed at strengthening the system and optimal distribution of the roof loads on the walls of the building.

The rafter system is divided into several categories, depending on the different features of its design.

Attic space

Before moving on to considering different types of roofs, it is worthwhile to figure out what an attic space can be, since many owners successfully use it as utility and full-fledged living quarters.

The design of pitched roofs can be divided into attic and attic. The first option is called this way because the space under the roof has a small height and is used only as an air gap that insulates the building from above. Such systems usually include or has several slopes, but located at a very slight angle.

The attic structure, which has a sufficiently large ridge height, can be used in different ways, be insulated and not insulated. These options include the attic or gable version. If a roof with a high ridge is chosen, then it is imperative to take into account the wind loads in the region where the house is built.

Slope of ramps

To determine the optimal slope of the roof slopes of a future residential building, first of all, you need to take a closer look at the already built low-rise neighboring houses. If they have been standing for more than one year and can withstand wind loads, then their design can be safely taken as a basis. In the same case, when the owners set the goal to create an exclusive original project, unlike the buildings standing nearby, it is necessary to familiarize yourself with the design and operational features of various rafter systems and make the appropriate calculations.

It should be borne in mind that the change in the tangential and normal values ​​of the wind force depends on how large the slope of the roof slopes is - the steeper the angle of inclination, the more important are the normal forces and the less tangential. If the roof is sloping, then the shear wind load affects the structure more, since the lifting force increases from the leeward side and decreases from the windward side.

The winter snow load must also be taken into account when designing the roof. Usually, this factor is considered in conjunction with the wind load, since the snow load on the windward side will be much lower than on the leeward slope. In addition, there are places on the slopes where snow will necessarily collect, giving a large load on this area, so it should be strengthened with additional rafters.

The slope of the roof slopes can vary from 10 to 60 degrees and should be selected not only taking into account the consolidated external load, but also depending on the roofing to be used. This factor is taken into account because roofing materials differ in their weight, for their fixing, a different number of elements of the rafter system is required, which means that the load on the walls of the house will also differ, and how large it will also depend on the angle of the roof slope. Of no small importance are the characteristics of each coating in terms of resistance to moisture penetration - in any case, many roofing materials need one or another slope to ensure the free flow of storm water or melting snow. In addition, when choosing the slope of the roof, you need to think in advance about how the process of cleaning and repair work on the roof will be carried out.

When planning this or that angle of the roof slopes, you need to know that the fewer joints between the covering sheets, and the more airtight they are, the less you can make the slope of the slope, of course, if it is not supposed to arrange a residential or utility room in the attic space.

If a material consisting of small elements is used to cover the roof, for example, ceramic tiles, then the slope of the slopes must be made steep enough so that water never lingers on the surface.

Given the weight of the roofing material, you need to know - the heavier the coating, the greater the angle of the slopes, since in this case the load will be correctly distributed to the rafter system and load-bearing walls.

The following materials can be used to cover the roof: either a profile sheet, galvanized steel, corrugated asbestos concrete and bitumen-fibrous sheets, cement and ceramic tiles, roofing material, soft roofing and other roofing materials. The illustration below shows the acceptable slope angles for different types of roofing.

Basic constructions of truss systems

First of all, it is worth considering the basic types of rafter systems in relation to the location of the walls of the house, which are used in all roof structures. Basic options are divided into layered, hanging, and also combined, that is, it includes elements of both the first and second types of systems in its design.

rafters

Nasal system

In buildings where internal load-bearing walls are provided, a layered rafter system is often installed. It is much easier to mount it than a hanging one, since the internal load-bearing walls provide reliable support for its elements, and in addition, this structure will require fewer materials.

For rafters in this system, the defining reference point is the ridge board, on which they are fixed. The spreader-free type of the layered system can be equipped in three options:

• In the first version, the upper side of the rafters is fixed on a ridge support, called sliding, and their lower side is fixed by cutting to the Mauerlat. Additionally, the rafters in the lower part are fixed to the wall using wire or staples.

• In the second case, the rafters in the upper part are cut at a certain angle and connected to each other using special metal plates.

The lower edge of the rafter legs is attached to the Mauerlat with movable fasteners.

• In the third version, the rafters are rigidly fastened in the upper part with bars or processed boards, located horizontally, parallel to each other on both sides of the rafters connected at an angle, and a ridge girder is clamped between them.

In the lower part, sliding fasteners are used to secure the rafters, as in the previous case.

It is necessary to explain why sliding fasteners are often used to fix the rafters on the Mauerlat. The fact is that they are able to relieve the load-bearing walls of excessive stress, since the rafters are not rigidly fixed, and when the structure shrinks, they can move without deforming the overall structure of the roofing system.

This type of fastening is used only in layered systems, which also distinguishes them from the hanging version.

However, in some cases, a spacer system is used for layered rafters, in which the lower end of the rafters is rigidly fixed to the Mauerlat, and in order to remove the load from the walls, puffs and struts are built into the structure. This option is called complex, since it includes elements of a layered and hanging system.

Specify the requested values ​​and click the "Calculate the value of excess Lbc"

Base length (horizontal projection of the ramp)

Planned roof slope α (degrees)

Rafter length calculator

The calculation is carried out based on the values ​​of the horizontal projection (Lsd) and the height of the rafter triangle, determined earlier (Lbc).

If desired, you can include in the calculation and the width of the eaves overhang, if it is created by protruding rafters.

Enter the requested values ​​and click the "Calculate rafter length" button

Excess value Lbc (meters)

The length of the horizontal projection of the rafter Lsd (meters)

Calculation conditions:

The required width of the eaves overhang (meters)

Number of overhangs:

Gable rafter system

Gable rafter systems are the most popular for one-story private houses. They look neat, fit well into any style of construction, are reliable and can be used, depending on the angle of their slope, to equip an attic for living rooms, utility rooms, or simply to create an air gap that keeps heat in a building.

wood screws

The positive effect of wood has always been appreciated by people, which is why we still see the use of this material both for wall installation and for the construction of roof structures. Wooden houses are beautiful, practical and comfortable. The final stage in the construction of any building is the roof, so keep in mind how a wooden roof is created by hand and how long it will last.

Wood, the first material used in the construction of residential buildings, is becoming popular with modern craftsmen. A few decades ago, the cost of such a roof was the lowest, and the installation was the easiest. Now things are different: the material is very expensive and the placement requires a lot of technical training and experience.

As before, a wooden roof with all the rules will allow you to get an exclusive design that will last for many years.

Description of the installation of a wooden roof

Depending on the materials chosen, the installation technique and the roof mast are determined.

The hardest part will probably be working with the cup. If the builder is inexperienced with such parts, then the wooden roof by hand may cause some problems or not work at all.

Outside the material, small plates (width - 10-15 cm, length - 40-70 cm) are presented, which are cut by hand or by hand. Due to the roughness formed in the cut, moisture is absorbed, so the material is of great importance with the presence of natural fibers.

On one longitudinal side, the slab is cut until the thickness reaches 3-5 mm, and on the other side, a wedge groove is cut with a depth of 10-12 mm, as shown in the figure. Ghosn consists of coniferous, brick and oak. A box (rod or rod with a part of 40 × 40 mm or 50 × 50 mm) is used as a basis for laying the lid. Timber roof design is done by fixing a shaft or rods with a 1/3-inch shaft length, and a solid foil can be formed from the panels.

Horizontal types of materials are located in accordance with one direction of the gutters and fix the narrow ends of the tiles in them. Once the slabs are aligned on the roof, they are crushed with the top edge against the tree. Nails must be inserted into the box at least 20 mm. The choice of nail depends on the type of wood, so cedar and larch are fixed with brass, while other types of wood can be fixed with galvanized nails.

How reliable a wooden roofing device is depends on the layer of pebbles:

1. For pavilions and commercial buildings, layers are sufficient, where the new line is located, covering half of the previous panel (see "How to make wood tiles, device roof").
2. The construction of residential buildings is carried out on the basis of three layers, and the new line is at the top of the previous one.
3. Buildings requiring high quality and reliability can contain a four-layer structure, with new lines positioned at the top of the previous ¾.

When laying, the upper slabs are located at the bottom to the middle of the previous row.

The definition of patchwork (roofing joints with a concave end) acts like a fan, which, on the narrow sides of the panel, is drawn downwards so that the tiles become trapezoidal.

Before setting up a wooden roof, all parts are pretreated with antiseptic agents, and use a fire-resistant compound to extinguish the fire. Also read: Rooftop Device.

The installation of proportions and cinematography is done in the same way as a cup. Since the boards are short (about 20-40 cm), the distance between the glowing rays decreases. The elements do not have common grooves, so they fit into the joint at the joint, taking into account that the tree can rotate over time (with a distance of 3-5 mm between the plates).

In damp weather, the joints of wooden roof structures will exactly match each other, and in warm weather they will create optimal conditions for ventilation of the timber.

Construction of a wooden roof in most cases of larch, which is different:

• high density and resin content, protection against corrosion and insects;
• duration of the operation;
• attractive wood structure;
• low price.

Characteristics of chip and tile roofing

Such material is embedded in three or four layers that overlap both vertically and horizontally.

The length of the shingle is attached to a wooden roof - its designs don't differ much from other types of structures like shingles. Neighbors should be covered up to 25-30 mm.

The new horizontal layer should be installed in such a way that the joints of the two lower straps are covered by one upper one. Each nail shield wearing shield is struck 70 × 1.5mm, followed by sewing a comb with a wood corner.

The construction of the slate roof follows the same technology as the shortened planks.

Usually they are offered in lengths from 40 cm to 10 m, width 9-13 cm, thickness 3-5 mm. The dimensions of the chips are somewhat smaller: length - 40-50 cm, width - 7-12 cm, thickness - 3 mm. Of these features, the chips are attached to the box with a pitch of about 15 cm, the holder is from 30 cm. Both materials are very light, so they must be at least 40 x 40 mm.

Roof coverings - various options, see video:

Roof features

If you build a wooden roof with your own hands, it will be the easiest and most affordable option for many just above the roof.

However, this coating will serve as less for the order, as a result of disruption of the natural structure of the wood when sawing. If you want to preserve the properties of the field, you must prepare slabs separating the logs in length, that is, in the same direction as the fibers of the material. Such coverage will be maintained with due care for at least one hundred years.

When building the roof of a wooden house, there are two ways of laying theses: transverse and longitudinal. The cross section method is the simplest timber roof device, but it is only suitable for temporary construction.

The nail plates, like any other cover, are from bottom to top with a 5 cm cover of the bottom row of the top.

The difference in the longitudinal method has several styling options:

• in the form of a two-layer coating - the plates are fixed with the upper layer, which moves to the lower part to the middle of the plate, and for swelling it remains 0.5 cm;
• in the first row, the plates are spaced 50 mm apart, the elements on the next line must be covered up to 50 mm from each previous plate;
• using the latch - the bottom line is solid, narrow strips should be used to cover the joints, which should be 50 mm.

Regardless of the method that restores wooden roofs, so that the top nail is securely attached to each row on a slab with a 600-800 mm pitch with a thickness of 19 to 25 mm, the cross-section of the beam is 60x60 mm.

Before choosing a material, read: How to Choose a Roof for Your Home.

1. Description of the used roofing materials

2. What elements does the roof consist of?

3. Features of supporting structures

In the construction of wooden houses, the task is to rationally combine the aesthetics and practicality of the roofing structure.

Among the large selection of materials, not all are suitable here, which significantly complicates the construction technology.

Following the main requirement, attention must be paid to ensure that the structure of the roof of a wooden house looks harmonious against the background of the entire building. Wooden houses have always been in special demand among connoisseurs of environmentally friendly and natural materials, and proper processing of logs allows you to achieve good thermal insulation, ease of installation and reliable fastening of curtain structures.

A significant disadvantage of a tree is its deformation during temperature fluctuations, especially - changes in the level of humidity, which must be taken into account when choosing one or another sawn timber.

Particular attention is paid to the order of assembly of window and door openings, exposure for the shrinkage of the log house. The problem areas include a wooden roof - its structure is erected according to certain rules (read: "Construction of a wooden roof - features of the coating"). As already mentioned, a special material is selected for it, it is installed under certain conditions, during operation it requires increased control than, for example, when building a roof on a stone building.

The shrinkage ratio of raw logs and beams is 10%, raw profiled beams reaches about 5%, dried and glued beams - up to 3%. Based on these values, in the project for the construction of wooden houses, two values ​​are noted - before the material has settled, and after that.

As a rule, the roofs of such houses are erected pitched, which is indicated even in the SNIP - flat and single-pitched wooden roof structures are considered impractical and outwardly unattractive.

A large selection of pitched configurations allows you to choose what the future home owner likes, for example:

A pitched roof has several advantages over other types of roofs:

• has the best thermal insulation of wooden floor trusses;
• under it you can equip an attic;
• cheaper roofing is suitable for it;
• snow masses descend from the roof as they accumulate;
• rainwater rolls down faster;
• long overhangs can be made, so that precipitation will be removed far from the walls.

Description of the used roofing materials

The construction or reconstruction of the roof of a wooden house is carried out using any of these coatings:

• materials to be welded on bituminous mastic, for example, European grinders;
• roll deposited materials;
• ceramic and metal tiles;
• slate;
• ondulina.

The use of euro-slate and corrugated board for wooden houses will lead to the appearance of noise from rain, and due to the reduced waterproofing properties, constant repair of the roofing cake will be required.

Truss system nodes - how to make a reliable roof?

The exotic version includes the arrangement of the roof in the form of a longitudinal overlap of edged boards, or "historical" materials (thatched roofs, from reeds). However, the so-called wooden roof - the design of which practically does not differ from traditional options, will be relevant in places where eco- or ethnic settlements close to nature are located. See also: "Roof of reeds".

What elements does the roof consist of?

The roof is assembled from several interconnected components, shown in the photo :

1. Slopes - sloped roof surfaces that can be flat or curved.
2. Skate - the upper longitudinal rib at the junction of the slopes.
3. The edges of a ramp, represented as a protruding angle at the intersection of ramps.
4. Endova, also called a groove, which is a concave intersection of the slopes.
5. Eaves overhang - a slight protrusion of the roof outside the frame (at the final stage, we hem the roof eaves with finishing material).
6. Gable overhang - the part of the roof hanging over the wall.
7. Gutter.
8. Downpipe.
9. Chimney.

Regardless of the choice of roofing, the structure of the roofing cake must be completely preserved.

For the lathing are taken: for metal materials and slate - bars or boards, for tiles only boards.

If materials based on bituminous mastic are used, then the crate is laid with a continuous sheet. In the case of using the attic or attic for living, interior decoration is also performed. But in any case, the order of stacking the layers of the cake must be respected.

So, if the owner of the house independently erects wooden roof structures, then you need to adhere to the basic requirements:

The rafter system of a wooden house, in detail on the video:

Features of supporting structures

Before the construction or reconstruction of wooden roofs begins, the scheme of its arrangement is carefully selected. The fastening of the pitched roof is carried out along certain rafters. The most common are the layered and suspended structures, which differ only in that in the first version there is an intermediate support, or a support for an internal load-bearing wall or partition.

The support should not be located further than 6.5 m from the outer wall, and the second support helps to increase each run - the distance from the middle support beam and the outer wall to 15 m.Mauerlat (rafter) in a wooden house is built from the upper wall row of logs ...

Hanging rafters are supported only by walls subjected to a bursting force.

For beginners who have no idea about such an installation, it is better to order a ready-made house project in a special company. Typical and universal structures of wooden roofs will be offered there, and an individual version can be developed (read: "Roof structure of a wooden house: which roof to choose").

If raw lumber is used in construction, then it is important to let the building settle, while the arrangement of the unit should be with special "sliding" elements.

As soon as the shrinkage of the rafters begins across the location of the timber, then with the help of such a wooden roof device, it will be possible to maintain their longitudinal binding.

By analogy with this, the rafters are fastened next to the ridge.

The result of such actions will be that even with significant shrinkage, the wooden roof structures will remain in their original place and will not deform.

Summing up, you should pay attention to the rather complex structure of wooden houses, the design and installation of which requires high professionalism. Beginners who do not have certain skills cannot cope with the work themselves. As for the choice of materials, types of roofs, everything is limited only by the budget of the owner of the house.

Read also the article: "Sheeting roofs - device".

Do-it-yourself hip roof: the construction process

The log house for the roof is ready.

Wooden roof - ecology, economy and reliability

It's time to make the roof rafter system. Let's consider the step-by-step process of its installation.

Consider the process of erection and construction of a hip roof (hipped roof), which consists of corner, intermediate and auxiliary rafters. The work is not very difficult, it can be done by a person without experience. The main thing is to make the correct calculations.

The erection of the hip roof begins with the installation of the Mauerlat, but since we have a log house made of a log under the roof, the upper log will serve as the Mauerlat.

Laying floor beams

So, it's time to mount intermediate floor beams, with a section of 10 by 20 centimeters and an intermediate step of 0.5-0.6 meters (there may be other values).

Attaching them to the timber is not difficult.

It is enough to lay the beams on top of the logs and fix them with metal corners.

You can make clearings in the logs. To do this, first you need to make an accurate marking of future holes, then take a chainsaw with a sharp chain and make cuts, with a depth equal to half the section of the log.

The height of the grooves should be 3 centimeters higher than the height of the beams in order to align them if necessary.

When the cuts are made, armed with a chisel and a hammer, you need to bring the matter to mind, giving the holes the desired shape.

Be sure to check the horizontal level of the beams.

Before laying the beams, their ends must be wrapped with pieces of Europen (insulation) dipped in an antiseptic solution, then additionally secure the beams with metal squares.

Skate installation

First you need to do the markup.

To do this, divide the gable walls in half (take the dimensions as accurately as possible).

Set aside the resulting size (from the center to the extreme wall) on the wall perpendicular to the pediment on both sides.

Repeat the same procedure on the opposite side of the hip roof.

The distance between the lines will be equal to the length of the ridge, the racks of which are installed at the intersection of the "squares".

Installing racks

For vertical uprights, we will use boards with a section of 5 by 15 centimeters, for a ridge - 5 by 20 cm.

The racks are set strictly vertically and supported by temporary braces on both sides.

Fastened with self-tapping screws.

There should be two boards in one rack.

A ridge bar is installed between the vertical posts (between two boards of one vertical post) and bolted. Additionally, a spacer can be mounted between the uprights.

Installation of rafters

The rafters must be mounted on the installed ridge girder. For this purpose, boards with a section of 5 by 15 centimeters are used (you may have others, depending on the calculations).

They are stacked in half a meter increments on a ridge run on both sides with an overlap. Then the boards are carefully trimmed with a saw at the top so that they can be butted together. The rafter legs are joined with metal profiles and self-tapping screws.

In the lower part of the hip roof of the log house, the rafters are installed on the Mauerlat by cutting, which is done at an angle of 90 degrees.

It rests on the upper log and is attached to it with metal corners using self-tapping screws or nails.

You can also make small grooves on the log, insert the rafter legs into them and fix in the same way.

The length of the boards should be such that the overhang behind the cornice is at least 30 centimeters.

This is how all the ridge rafter legs are installed.

After the installation is completed, the installation of the corner rafters begins.

Installation of corner rafters

The first to be mounted are the corner rafters, which run along the center of the pediment. The section can be left the same.

Their length can be calculated by the Pythagorean theorem.

But you can simply place a temporary board between the ridge and the center of the gable wall beam and measure it.

Then add to the obtained value from 30 to 50 centimeters, which "go to take away."

Along the board, you need to prepare another one, on the opposite side, and then fix both to the skate and the Mauerlat below. The boards are attached to the Mauerlat using the cutting method.

Similarly, the rafters are procured and mounted on the four corners of the hip roof of the log house with their own hands.

Under all the rafter legs, it is necessary to install racks near the Mauerlat.

Installation of intermediate rafters

It remains only to install the intermediate rafters.

To do this, the walls are marked with the chosen step so that there is always a right angle between the marks on the adjacent walls. At the intersection of the two lines, a mark is made on the corner rafter.

Further, all distances are measured, the rafter legs of the required length are prepared, taking into account the eaves overhang, and their installation is carried out.

To fasten the intermediate rafters of the floating roof for a log house to the corner rafters, their ends must be cut at an angle of 45 degrees and bolted.

To simplify the calculations, you can nail a board between the corner rafter legs and "dance" from it.

If the boards are not long enough, they can be spliced ​​in various ways.

When all the rafters are installed, it is necessary to mount eaves boards around the perimeter of the hip roof, and then proceed with laying the sheathing and roofing material.

The type of lathing for the hip roof of a log house depends on what kind of roofing material you plan to use.

If soft roofing materials are used, for example, shingles, then the base must be solid.

A sparse crate is made for rigid materials.

The step of the lathing also differs depending on the material for the roof.

The required step value is usually indicated by the manufacturer of the roofing material.

When installing a roofing cake, it is imperative to use insulation, steam and waterproofing. You can read about how to install a certain type of roofing on our website in the relevant articles. The sequence of works is described in detail there. To simplify the calculation of the elements of the hip roof, you can use the programs.

Hip roof, rafter system

Terms used in the construction of wood veneers

• The rafters are the load-bearing part of the roof, which includes multilayer supports, pillars and vertical columns supported by Mauerlat.
• The skobel is part of the gorge.
• Mauerlat, presented in the form of supporting several rafters, or in other words, on a bar placed at the top of the wall, evenly distributes them to the load on the roof, it is important to understand why you need a Mauerlat.
• Tightening - A guide that is horizontally positioned to connect the roof tiles and reduce horizontal collision on them to ensure stability on the roof is also used as a holder.
• Headstock - strengthens the scissors, sets: lower part - tightens; upward - as support for the rafters.
• The spacer is attached as a connecting piece between the logs.
• The hanger is in the form of an inclined beam, which is used to support the beams of the tree, which lie against the horizontal parts (columns and columns).
• The horse is horizontally mounted on the roof of the roadstead.

When constructing hinges, wooden roofs can be divided into several groups:

1. connecting legs with Mauerlat;
2. connecting legs and elements of the wooden base for the roof, which makes the structure more solid and durable;
3. A knot with flat pieces is connected by pulling out of it.

Depending on the desired result, the rafters are connected to the Mauerlat with a rigid or sliding knot.

It should be noted that in some cases, a rigid installation can even destroy the structure, as in the picture, since the weather conditions are favorable for pressing and opening the wood, but due to the rigid connection of the nasson system, it can deform the bearings of the wall under heavy load.

Features of rigid nodes

The solid knot of a wooden roof has the following shape:

1. Cutting is done at a depth of one third of the panel at the shoulder.

   The machines must then be attached to the Mauerlat with nails so that two of them fall at a slight angle to the side of the rafter and one in the vertical direction.

2. For a 1 m rafter, the lifting timber is installed in place as a support for the Mauerlat, the side fixing screws are screwed in this position with metal corners.

Sliding knot characteristics

The connection of the elements of the nasal system is carried out using sliding knots.

The use of suspended rafters is useful in a round timber roof structure where the spine pole is used to support the rafters and no spacing occurs between the load-bearing walls.

Newly built wooden farmland will be saved within a few years, so using rigid fixtures to move the farm permanently will deform the walls.

To avoid such problems, wooden roofs are scissor units that must be defined with a free movement permit, constructed as follows.

The curved leg, using a pre-made saw, rests on the Mauerlat and is tied (two on each side, the third vertical).

1. Metal tiles dropped from the wall are attached to metal corners that connect them to the Mauerlat.
2. Metal structures are determined by the "footprint" method (see "Metal truss, cons and advantages").
3. The leg support in the Mauerlat should be carried out taking into account the movement of these systems in relation to each other.
4. In the event of a stormy wind, the roofs are not damaged, the bracing of struts, shepherds and gaskets to the suspended rafters is carried out using clamps and clamps; there are also twisted wire rolls around the leg.

How to connect round legs

If the roof stretch is large enough, special attention should be paid to the wooden roof hinges as well as the columns, which will need to be expanded to the desired dimensions using one of the suggested methods.

How to connect pile rafters in construction

The developers pay special attention to the top-comb connection mode.

The main findings of the scissor system detailed in the video:

Difference between teeth and "tip"

1. Due to its high strength, the spike connection is excellent for timber construction.

   The tip is the part that attaches to the journal that connects to the socket, tongue, or ear of the second journal. The size and shape of these two elements must match each other.

2. The tooth is connected with a stepped incision in one day and with inscriptions in the other. As in the case of the previous method, the ratio of their size and shape must be taken into account for a tight fit of timber roof structures.

If the designer is building a wooden roof, when connected to the roof elements, the knitting feet must be secured with screws, screws, clamps and screws.

The hole diameter should be between 1 and 2 mm of the fasteners, and the brackets are fixed on both sides.

When using a screw connection on the scissors, a screw located at the top of the structure is used and the groove cut is performed at half the thickness of the log.

Only if these requirements are met, the journals will closely coordinate with each other. In the next step, the assembly is attached to screws and special brackets.

A flat roof can be avoided smoothly - knots can be of any shape, with the same scissors. Experienced builders recommend the design of the template so that all frames and cuts are the same size (see: Wooden Roof Construction - Cover Specifications).

The description of the entire roof structure is provided by the most complete presentation, but the wooden cart, which is quite difficult for beginners, requires a professional approach. Also read: Building a Wooden House Roof: Which Roof You Should Choose.

A pitched roof of a house consists of a large number of parts, each of which is connected to others in a special way. This connection is called a roof node. In this article, we will talk specifically about the connection nodes, how it is carried out, what technologies are used, what fasteners are used.

The main parts of the roof structure

Before proceeding directly to the analysis of the topic of the article, it is necessary to indicate which elements (parts) the roofing structure consists of. We will list all the main details and indicate their purpose.

Mauerlat... This is a beam that is laid on the walls of the house, located along the perimeter of the building. The purpose of the Mauerlat is to evenly distribute the loads emanating from the rafter system. After all, if there is no Mauerlat, then each rafter will press on the wall pointwise. And it is in this place that the destruction of the wall structure will occur.

Rafter legs... They are made either from boards with a thickness of at least 50 mm, or from beams. The rafters are the basis of the roof, it is they who form the slopes and bear all the loads acting on the roofing structure.

Ridge run... This is the topmost beam, installed horizontally. Its purpose is to support the upper ends of the rafter legs. It is he who forms the ridge of the roof.

These are the three main elements of the roof, which will be discussed further. Of course, these are not all the details of the roof, and one cannot say that others are less important. It's just that these three elements form the structure itself. The only thing to add is that in some roof structures there is no ridge girder. It's just that the upper ends of the rafters abut against each other. This type of rafter is called hanging, and with a ridge run, layered.

So that the roof structure is the most reliable, it is necessary that the nodes of the roof are connected correctly. In this case, the force of the acting loads and their direction must be taken into account.

How to connect elements of the roof structure

More recently joining the nodes of a wooden roof carried out with the help of cuts. That is, the elements of the roofing structure were cut to connect them along one fairly wide plane. Therefore, so that the roof parts do not reduce their strength characteristics, as well as the bearing capacity, they were selected with a sufficiently large section. And this is not economical. That is, the larger the cross-section of the lumber, the more expensive it costs.

Today, the technology of fastening nodes and parts of the roofing structure has changed dramatically. To do this, use bolts, pins or metal perforated profiles. The latter are made of galvanized steel, which makes it possible to operate fasteners for a long time without losing their quality. At the same time, manufacturers offer a fairly wide range of them for each type of assembly. The photo below shows some of these fasteners.

It should be noted that perforated profiles gradually replaced all other types of fasteners due to the strength, reliability and ease of fastening operations. After all, for this you just need to install the profile in the required place and fix it to various parts with wood screws or ruff nails.

Let's now see how it should be fix parts the roof structure between each other. In principle, there are two types of connection: mauerlat-rafters, rafters-ridge girder. The rest of the parts are connected parallel to these joints. He will also talk about them.

Mauerlat and rafters connection

There are actually a huge number of fastening options, from ordinary nails to perforated profiles. For example, the photo below shows an option where ordinary wire is used as fasteners. That is, a through hole is made in the rafter itself, where a wire with a diameter of 6 mm is inserted. A hole is made in the Mauerlat or in the ceiling beam.

Then the ends of the wire are pushed into this hole and twisted, pressing the rafter leg against the Mauerlat. The connection is actually strong and reliable, but the process is laborious.

Instead of wire, you can use metal tape 3 mm thick. It is simply wrapped around two connected elements and through a strip they are attached to them with self-tapping screws, more often with nails. In the latter case, there is no need to drill through holes in the metal. note that in the lower photo the fastening is carried out to the reinforced belt with an anchor, which increases the strength and reliability of the connection.

On our website you can find contacts of construction companies that offer the service of calculating and carrying out roofing works of any complexity on a turnkey basis. You can communicate directly with representatives by visiting the Low-Rise Country exhibition of houses.

The next type of fastening is a perforated galvanized steel corner. The most convenient option, but the most reliable. To do this, the corner is simply installed so that it presses tightly against the plane of the Mauerlat and the rafter leg with its mounting shelves. Fastening is carried out with self-tapping screws or nails.

Fasten corners it is possible not only with self-tapping screws or ruff nails. There is another more reliable option where bolts are used. True, holes will have to be made for them, which increases the costly time for carrying out this type of work. But in this case, quality is paramount. In the photo below, just such a mounting option is shown. Please note that the corner is attached to the Mauerlat with self-tapping screws, and to the rafter leg with a bolt. In this case, one bolt is used to connect two angles located at opposite ends of the rafters.

And one more mounting option - on the slider... It is a special type of two-piece fastener. One is attached to the Mauerlat, the second to the rafter leg. In this case, both parts are not tightly connected to each other. This is done specifically so that the rafters can move relative to the Mauerlat during the thermal expansion of the lumber. This means that there will be no loads that act on the joint of two roof parts. The photo below shows this connection option.

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Connecting rafters with a ridge girder

The second main node of the wooden roof is the joint between the rafter leg and the ridge bar... In fact, the ridge knot of the rafter roof is very complicated, because two rafter legs and a beam are joined on it. In this case, all elements are located in different planes, meaning rafters and timber. This means that more than one fastening element will have to be used to connect them.

To connect the rafters to each other, use perforated plate... There are two of them, installed on different sides of the rafter legs to increase strength and reliability.

Perforated corners connecting the rafters to the Mauerlat. There are four of them, two for each rafter leg, installed on different sides.

It should be noted that fastenings can be carried out not only with screws or nails. Often, masters use bolts for connection paired fasteners.

Pay attention to the different type of fastening. Only corners are used here. This option is used if a board with a thickness of 50 mm is installed as a ridge bar.

Another interesting option for attaching the rafter legs to the ridge span, for which they use special perforated complex shaped profiles... In fact, these are brackets into which the rafter leg is inserted. The bracket not only holds the parts together, it supports the rafter, reducing the stress on its end.

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Pay attention to all of the above options for connecting the rafters to each other. They clearly show that the ends of the rafter legs are joined tightly to each other, for which they have to be filed at a certain angle. You can do without filing if you use a complex fastening lock, consisting of several plates that are bolted together. In the photo below, this connection option is clearly visible.

Hanging rafter connection

The rafter system of this type differs from the layered one in that it does not ridge run... That is, the rafter legs in the upper part (ridge) abut against each other. In order for them not to disperse in different directions, the rafters are connected to each other by horizontal tightening. The latter is a board located at any distance in height: top, bottom or in the middle.

It should be noted that hanging rafters on the roof separately are not assembled. Of these, farms are assembled on the ground, which, in finished form, are installed on the roof of the house. In this case, all elements of the truss are interconnected with perforated plates.

Video description

In the video, the master tells how to assemble a truss truss using perforated plates and nails:

Other types of nodes

As mentioned above, there are many details in the roofing structure. Therefore, we will tell and show a few more important connection nodes.

If the span of the house is more than 6 m, then a rack is installed under each rafter, which itself should rest against either a concrete base or a floor beam. In this case, the connection of the rack with the rafter leg is carried out with ordinary boards, as shown in the photo below. Although perforated metal plates can be used.

A ridge bar is also installed vertical support posts, which are fastened together with perforated plates. But in some roof structures, a completely different approach is used to solve the installation of a ridge girder. Jibs made of bars are mounted under the timber, which are fixed to the ridge with special fasteners made of metal. The photo below shows one of the options for this type of fastener.

Very often, when constructing a rafter system, it becomes necessary to lengthen the rafters themselves. It is not difficult to do this, while the craftsmen use several technologies, where they use various additional fasteners.

Video description

The video shows one of the options for lengthening the rafters:

Roofing structures are several varieties of their shapes. Almost all models have a large number of the same elements. But there is one design among them, which differs significantly from the others. it hipped roof... Its distinctive feature is that the rafters are connected with the upper edges at one point, which is called the ridge knot.

So, in order to connect the rafter legs to each other, you need a support to which they are attached. There are several ways to ensure high reliability of the node. The photo below shows one of them, which uses U-shaped perforated metal profiles.

Conclusion on the topic

In fact, we have considered only a small part of the connecting nodes for fastening the roof truss system. But even on their example, the variety of parts and assemblies becomes clear. That is, the roofing structure is a complex system, consisting of a large number of different elements and parts that are interconnected in different ways.

December 12, 2017
Specialization: facade decoration, interior decoration, construction of summer cottages, garages. The experience of an amateur gardener and gardener. He also has experience in repairing cars and motorcycles. Hobbies: playing guitar and much more, for which there is not enough time :)

Any roof is subjected to various loads every day, as it is affected by wind, precipitation, and it also holds the roof covering. In order for the roof to cope with all these loads for many decades, it must be properly designed. Therefore, for everyone who wants to start building on their own, I recommend that you figure out what parts and nodes of the rafter system exist, and what function they perform.

Frame elements

All parts of rafter systems can be conditionally divided into two types:

• Basic. These parts form the roof frame, called the rafter system. Not a single roof can do without them;
• Additional. This group includes elements that may be present in some types of roofs, while others do without them. The task of the additional elements is to increase the rigidity and strength of the frame.

Main nodes

So, the following elements belong to the main units and parts of the rafter system:

• Mauerlat... This, one might say, is the basis of all roofing systems, since the rafter legs rest on the Mauerlat. Its design is extremely simple, in fact, it is an ordinary bar (a log in log houses), laid along the perimeter of the walls. Its task is to evenly distribute the load from the roof to the walls of the building.

I must say that at a gable roof, the Mauerlat can be located not along the perimeter, but only on the side walls, since gables are located on the end walls, which are a continuation of the wall;

• Rafter legs (hereinafter CH), or just rafters. These parts are the load-bearing element that forms the ramp and its angle of inclination. They take on wind and snow loads, as well as the weight of the roofing material, and transmit them to the walls through the Mauerlat and other elements.

Rafters are lateral (main), diagonal (installed at the junction of the slopes of hip roofs) and shortened (diagonal rafters rest on the Mauerlat);

• Roof trusses. They are formed by paired (reciprocal) rafter legs. I must say that roof trusses are present on all pitched roofs except for single-pitched roofs, since they do not have reciprocal rafters;
• Ridge knot. It is the top of the truss, i.e. formed by the junction of two SN. The ridge knot, like the farms themselves, is absent only on pitched roofs.

These are all the main nodes of wooden roof structures that form them.

Additional

Additional details include:

• Run... It is a horizontal beam that connects all CHs within one slope;
• Ridge run... It is the same horizontal beam as a regular purlin, but which passes in the ridge knot, i.e. connects simultaneously two legs of each truss.

I must say that the ridge girder can be installed in several ways - above the rafter joint, in the center of the joint, i.e. legs rest on the girder, or under the rafters;

• Tightening (crossbar, scrum). It is a beam that connects two reciprocal legs, preventing them from moving apart. We can say that the tightening removes the spacer load from the load-bearing walls;

• Supports. Can support rafters, all types of purlins or tightening. Supports transfer the load to the internal walls of the building, columns or floors;
• Braces (rafter legs). They are inclined supports, which have the same function as vertical posts. The only thing is that they only support the legs, i.e. are one of the elements of wooden trusses. The rafter legs transfer the load to the load-bearing elements of the building, or to the floor;
• Filly. These elements form a slope overhang if the CH does not go beyond the walls. In fact, they lengthen the CH, i.e. are their continuation.

These are all the elements that make up the frames of pitched roofs.

A few words about the types of systems

So, we figured out the nodes, now let's look at the main types of rafter structures. There are several of them:

• Single slope... As I said, these structures do not have trusses. The angle of the slope is formed due to the different heights of the walls on which the CH is laid, or due to the run, which is placed on the racks installed on one of the walls;

• Gable... Inclined rafters are rafters that are supported by racks or struts that transfer the load to the internal load-bearing elements of the building. The framework of such structures is formed only by trusses, i.e. they do not have diagonal legs.

• Gable hanging... Hanging rafters differ from layered ones in that they transfer all the load from the roof only to the outer walls;

• Hip... Unlike gable ones, instead of vertical gables, they have inclined hips at the ends, i.e. end slopes. As I said, the hips form diagonal and short legs;

• Broken lines. They represent a gable structure, each SN of which is divided into two parts and is located at a different angle. Skate, i.e. the upper legs form a gentle slope, and the lower legs form a steep one. This design allows you to increase the attic space, as a result of which it can be used as an additional floor.

Typical broken (attic) systems have racks on which the upper and lower CH are supported. The counter pillars are interconnected by ties (attic floor beams).

There are also semi-attic structures, which, in fact, are conventional hanging gable roof systems. The only thing is that their fastening with the Mauerlat is usually made sliding (movable), which allows you to increase the deflection of the CH, and thereby reduce the spacer load on the walls.

Despite the fact that the designs of all of the above systems are different, they consist of the same parts, which we have already familiarized ourselves with.

Finally about the mounts

Finally, I propose to consider how the main nodes are connected, such as:

• Rafters / Mauerlat;
• Ridge knot.

The rest of the details do not deserve special attention, since their docking most often occurs by washing down the mating points (to increase the area of ​​contact of the parts) and lining of steel plastic / corners, which are fixed with screws. Sometimes the fasteners are not even used, i.e. the parts are attached to each other with screws without any overlays.

The connection of the rafter and the Mauerlat

The leg and Mauerlat attachment assembly can be performed in several ways:

• With grooves... In this case, grooves are cut out under the Mauerlat, into which the CH is inserted. Then it is additionally attached to the Mauerlat on both sides with a steel corner;

• Tooth and thorn... This method is usually used for fixing the MV to the tightening. Its principle is based on the fact that a spike is selected at the end of the sawed-down CH, and a groove is selected in the tightening. In addition, the leg itself rests on the so-called tooth, i.e. a projection in the tightening, which takes the spacer load.

It must be said that lately, the fastening of the type of a tooth with a spike is rarely used, since it is much easier to use special fasteners, the same corners and plates;

• By drinking... In this case, the CH is filed so that a right angle forms at the junction with the Mauerlat, as a result of which the rafter not only rests on the beam, but also rests on its lateral surface, thus transferring the spacer load. I must say that instead of a gash, you can fix a bar, as shown in the diagram below.

The connection of the rafter and the ridge girder

The connection of MV and purlin can be done as follows:

• With a groove. In the SN, two reciprocal cuts are made, as a result of which, after the junction of the rafters, a groove is formed for the ridge girder;
• Hard pinching. The principle is based on the fact that puffs are installed under and over the girder;

• I washed it down. This is the simplest and most common method, the principle of which is based on filing the CH for maximum adherence to the beam. In this case, the fixation is carried out with a steel corner.

These are, perhaps, all the main nuances of the assembly of truss systems.

Output

We have found out what parts the rafter systems consist of, what types they are and how the connection of their main elements is carried out. If I missed some points or something is not clear to you - write comments, and I will gladly answer your questions.

December 12, 2017

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