Composition of a pitched roof. Types of flat roofing. Types of flat roof

1.
2.
3.

The appearance of the building depends, among other things, on the shape of the roof, which can be flat or sloped. There are exclusive options when roofing design solutions involuntarily attract the attention of people passing by. An important parameter by which the shape of roofs differs is the slope of the slopes: flat structures include those in which the height difference between opposite edges does not exceed 3%.

This indicator means that there is a 3-centimeter difference per linear meter of coating. As a rule, flat roofs are built with a pitched roof, which means that the roof surface is in the same plane. IN Soviet period in the post-war years, this form of roof was used in construction multi-storey buildings, the so-called “Khrushchev” and during the construction of industrial facilities. During their operation, it turned out that flat roofs often leak and their maintenance is more expensive than pitched roofs with attic space. Therefore, it was decided to replace flat designs on apartment buildings residential buildings on pitched forms.

Two or more flat slopes are installed on buildings with a large area, but this solution is used extremely rarely by architects.

Basic roof elements

The final stage of building a house is the installation of a roofing covering that will protect interior spaces from wind, precipitation, sizzling sun rays and other natural phenomena. How successfully the roof construction is completed depends further exploitation building. Reliable roof- the key to the durability of the structure.

Despite big choice roofing materials and a variety of design solutions regarding the creation of roofs, they have common elements:

• ceiling - a flooring made of reinforced concrete slabs or other building materials, which rests on a load-bearing base and covers the top floor. It usually serves as a ceiling for rooms located at the highest level of the building;
• roof frame - load-bearing structural elements of the roof, as a rule, it is a rafter system that absorbs the loads from the roofing “pie”;
• roof covering - a layer of material specifically designed to protect a structure from environmental influences.

The main layers of the roofing “pie” (what the roof is made of) are arranged from the inside out in the following order:

• vapor barrier;
• insulation;
• waterproofing;
• coating material.

For pitched roofs, a rafter system and sheathing must be built, usually from wooden and metal fasteners. If you plan to create an attic space, then you will also need a counter-lattice.

The lathing (you can see how it looks in the photo) can be solid or sparse, depending on the roofing material. It is intended to strengthen the roof structure, since it is attached perpendicular to the rafters, resulting in a stiffening belt. The solid option involves the use of moisture-resistant plywood or other sheet materials. The sparse type of sheathing is made from timber or boards, which are installed at certain intervals.

How to choose roofing material, see details in the video:

Choosing a roof type

Usually choose specific type pitched roof, taking into account the climatic characteristics of the region and the traditions that have developed in a particular territory. So in the north Russian Federation and in Finland, where winter lasts a long time and is characterized by heavy and frequent snowfalls, gable roofs with long overhangs have been installed for many years. For example, in an alpine chalet they almost reach the surface of the earth.

The roof slope is also affected by the average annual precipitation in the natural area where the house is being built. For example, when the slope of the slopes is 60 degrees or more, snowdrifts on the roof do not lie for a long time, but roll down along it. In areas where a cold climate predominates, in winter there is always the problem of cleaning roofing surfaces from snow.

In Western European countries, there has historically been a tendency to install different types of hip roofs with four slopes. Their roof sections located along the length of the house have the shape of a trapezoid, and on the end side they have the shape of a triangle. The hips are triangular-shaped slopes, and the trapezoidal slope is called that. No less popular are half-hip roofs, consisting of hips with smaller overhangs than the side slopes. Received a similar form widespread in Denmark and therefore it is also called the Danish roof. There is usually an entire attic floor underneath it.

Gable roofs have gables made of the same material as the walls of the building and heat transfer from such roofs occurs through the slopes. By replacing the upper part of the walls, hips allow you to save on masonry walls, which is convenient for homeowners living in southern regions, where a thermal insulation layer can be included in the roofing composition. The disadvantage of hip and half-hip roofs is that the rafter system has them complex design and the places where the slopes connect require special attention.

Any type of roof can be not only straight, but also broken, in which the slope varies within the surface of the slope. Similar roofing structures are used in the construction of attics. A type of broken roof is considered to be a half-timbered roof, which is very popular in buildings belonging to old Western European architecture. It simultaneously combines gable and hip (half-hip) roofs, and sometimes has a cone-shaped roof.

The most difficult in terms of execution is considered to be a multi-gable roof, which has the most unusual and original appearance; it requires careful calculation and measurement of the roof during design. When creating it, several slopes are connected at different angles. Sometimes the combination is performed at different levels, not only horizontally, but also vertically. Such roofs are often obtained when an additional room is added to the house, while the outer wall existing house becomes a wall in a new building. A more economical option is when you do not make a separate roof for the extension, but install an additional gable to the existing roof.

The project is optimal solution for motels with separate rooms, and for cafes with small banquet halls, which have a separate entrance from the street and are located at different angles to each other. In this case, each room is equipped with its own tong.

For private households, a multi-gable roof is installed if the owner wishes to make the roof aesthetically attractive and exclusive in appearance. To build it, you will need a project developed by specialists and a team of roofers, since it is too difficult to build it yourself. Otherwise, multiple defects in the roof will make it and the entire building unsuitable for use.

A variety of decisions regarding appearance can make choosing the best option difficult, and then professional advice will not be superfluous.

The choice of materials for the roof largely depends on the design of the roof. Let's look at the main types of roofs and some of their individual elements. Roofs are divided into flat and pitched. Roofs flat type used for construction outbuildings(barns, bathhouses and others). Residential buildings are increasingly being covered with pitched roofs. Pitched roofs can be divided into attic and non-attic. As a rule, attic roofs do not require thermal insulation. Roofs of the attic type can be warm (located above heated rooms) or cold (above rooms that are not heated).

The attic can be used as an additional room for utility purposes. It promotes better ventilation at home, if there is stove heating, then it is located in the attic chimney. Increasingly in attic Many craftsmen create attics.

Types of pitched roofs

• single-pitched, their support is two external walls, which different heights;
• gable, supported by two external walls of equal height;

half-hip (or gable), the upper parts of the end walls of which are cut in the shape of a triangle (also called hip);

the hip and end slopes of such a roof have the shape of beveled triangles, and the side slopes are trapezoidal;

hipped roofs, the four slopes of such roofs are made in the shape of identical triangles that converge at one point;

attic or broken gable roofs, each of their planes is two rectangles that are connected to each other at an obtuse angle.

Types of pitched roofs

A - flat gable;
B - steep gable;
B - hip hipped;
G - single slope;
D - broken (attic) gable;
E - hipped hipped;
F, Z, I - semi-hip hipped.

The most convenient and economical option are considered pitched roofs, the slope of which does not exceed 5%. Inner space buildings are used to the maximum, while they can simultaneously serve as a ceiling in utility buildings (baths or sheds, garages, etc.), where strict horizontality is not required.

If there is a need to use the attic for storing things, drying clothes or installing an attic, then the roof of a residential building is made of a broken or gable roof.

Hip roofs are better able to withstand wind loads than others, but their construction is quite labor-intensive and requires professional skills.

When making a choice in favor of one type of roof or another, do not forget to take into account not only operational, but also decorative characteristics. For example, a high roof on one-story building will not only give it a more impressive and attractive appearance, but will also allow you to use the additional attic space for your own purposes. In addition, snow practically does not linger on steep roof slopes.

Basic roof elements

The roof includes the following elements:

• load-bearing structure, which is created from rafters, wooden beams or prefabricated trusses, which include a lower and upper chord and a grid of struts and bevels located between them;
• roof base;
• thermal insulation and waterproofing layer;
• the roof itself.

As for the beam roof structure, it is advisable to use it with a span length of less than 4.5 m, and trusses - about 5-10 meters.

Rafters

As an integral element of the roof, the rafters have a very important function: to support the sheathing. They take on the pressure of snow, moisture and wind, all roofs. According to their design, they are divided into layered and hanging. Layered rafters are used if the roof span (the so-called distance between supports) is less than 6.5 meters, and if there is additional support - 10-12 meters.

Hanging rafters are used if the roof span does not have additional supports and is 7-12 meters. Their main difference from layered ones is that they transmit only vertical pressure to the Mauerlat. Bottom chords and rafter legs are the main components of hanging rafters.

Layered rafters:

1. rafter leg;
2. crossbar;
3. attic floor.

Hanging rafters:

1. Mauerlat;
2. rafter leg;
3. puff;
4. grandmother;
5. brace

Depending on what material the house is built from, rafter legs can be attached:

• using the top strap in;
• on the upper crowns in chopped, wooden and cobblestone buildings;
• on special support beams, which are also called mauerlat in stone buildings. In this case, the Mauerlat should be 15-16 cm thick; it itself can be partial (the beams are placed only under the rafter leg) or solid (running along the entire length of the structure).

If the rafter legs have a small cross-section, then you can prevent them from sagging if you use grids of struts, racks and crossbars. Struts and racks can be made from boards 15 cm wide and 2.5 cm thick, or from wooden plates cut from logs with a diameter of at least 13-14 cm.

During installation, the rafter leg is cut into the tie. To prevent the end of the leg from slipping and chipping the tie, you need to cut it in with a tooth, its height should be 1/3 of the height of the tie, with a spike, or both methods. In addition, the tie will remain intact and will not chip if the rafters are installed at a distance of approximately 3-4 cm from the edge. The rafter leg needs to be cut into the end of the tie, in turn, the tooth must be moved as far as possible.

To strengthen the rafter fastenings, you need a so-called double tooth. The teeth can be the same height, but most often they are selected so that the height of the first is equal to 1/5 of the thickness of the puff, and the second - 1/3. To secure the first tooth, a stop, a tenon and an eye are placed on the rafter on the tightening, and for the second - only a stop.

To further secure the rafters in the ties, you can use bolts or clamps. Bolts are not used so often, since they can weaken the cross-section of the tie rods and rafter legs.

If the struts have a headstock, they are connected to a notch, while the nest is made in the headstock, and a tenon is cut out in the strut. A connection of this type in hanging rafters requires additional fastenings with clamps or bolts. The crossbar is connected to the rafter legs by a half-tree cut. This connection is secured with a dowel and a bolt, and to give it greater strength, also with a bracket.

The main tightening elements are fastened together with a tooth, a metal plate and bolts. The tightening is connected to the headstock using a clamp. To protect the walls of the building from atmospheric water, the roof overhang must have a length of at least 550 mm.

In addition to the fact that the ends of the rafter legs are secured in the tie, they are also additionally hooked to the walls of the building using so-called twists. In this case, the roof will not be damaged in strong winds. A twist is an impressive piece of thick wire, with one end it is wound to a rafter leg, and the other to a crutch, it is driven into the seam of stone or brickwork at a distance of 30-35 cm from the top edge of the wall, or to the floor beam of the attic. If the house is made of wood, then the twist can be replaced with an iron bracket that connects the rafters and the second crown of the frame.

Reinforced concrete rafter legs in layered rafters must be laid at one end on outer wall building, and the second - on a precast reinforced concrete girder, which is supported by brick columns. The lower ends of the rafter legs, which protrude beyond the wall, are capable of carrying eaves overhang roofs. When you choose a material for rafters, you need to take into account many factors: the weight of the roof, the distance between the rafters, the length of the rafter leg, etc.

The base can be made of rolled or piece materials in the form of flooring or lathing. To make the sheathing you will need blocks of wood, and for the flooring you will need not only bars, but also boards. It is advisable to make a continuous flooring if roll material or asbestos-cement tiles are chosen for the covering. For tiles, flooring boards are laid out in one layer with a small gap, and for rolled material - in two layers: working and protective. For the protective layer, narrow boards are chosen, which should be located at an angle of 45 degrees to the worker. Between the two floorings you need to place an anti-wind roofing felt lining (roofing felt grade RPP-350 or RPP-300).

Lathing will be required in cases where the roof will be covered with sheet steel, tiles, wood or corrugated asbestos cement sheets VO (or slate).

When making a base, you need to follow two simple rules: each element must be securely attached to supporting structures, and their joints are located at intervals above the rafters.

In addition, the specified distance between the bars or boards must be strictly observed over the entire surface of the base. The widest ones are located at the eaves, ridge or under the joints of the roofing material, and the thickest (15-35 mm thicker than others) are located near the eaves. Under the gutter, the base must be at least 750-800 mm wide, and under the eaves overhang with wall gutters, the base must be equal to the width of the overhang. On roof ribs and ridges, wooden blocks must be installed on the edge.

Roof

The roof is the top covering of the roof, which provides protection from precipitation to all structural elements of the structure and drains water to the ground. That is why one of the main requirements for a roof is water resistance. The roof can be made from various building materials, asbestos-cement or steel sheets, rolled and local (clay-reed and clay-straw) materials.

As for the design, the roof covering may consist of:

• slopes (inclined surfaces);
• inclined ribs;
• ridge (horizontal ribs).

Valleys and valleys are the name of the places of intersection at an incoming angle, and eaves and gable overhangs are the edges of the roof that extend beyond the building horizontally or at an angle. Atmospheric water from the roof slopes is collected in wall gutters, then it enters water intake funnels, and then into drainpipes and storm drains.

The roofing components can be laid both transversely and longitudinally, connecting them with an overlap (most roofings) or in a lock (roofing steel sheets).

According to the roof structure, they are divided into:

• single-layer (consist of VO sheets, steel, asbestos-cement tiles and seam tiles);
• multilayer (roll materials, planks, shingles, shavings, flat strip tiles).

In multi-layer roofs, the number of layers will range from 2 to 5, it depends on the material you choose. This type of roofing is quite labor-intensive and less economical. If in a multi-layer roof each layer lies in the transverse direction, it must certainly overlap the joints of the elements of the layer lying below. If it is placed in the longitudinal direction, it must cover the underlying layer with an overlap established by GOST.

The role of the roof slope is very important, because it helps remove precipitation from the roof. It is expressed as a percentage or degrees. Basically, when building houses, roofs are made flat, the slopes have the same slope.

The roofing slope you choose will determine both the coating material and the type of drainage of rainwater from the roof. Drainage can be organized (internal or external) and unorganized (external).

The structure of the internal organized drainage system includes a riser, a water intake funnel, a drain pipe and an outlet. This design can be used in all climatic regions.

External organized drainage includes gutters and external drainpipes. It can be used in climate areas where the water in the drainpipes outside hardly freezes.

If the drain is unorganized, then the water will flow along the entire length of the lower edge of the slope; no additional devices are required. This type of drainage is indicated for climatic areas where the amount of precipitation is low.

Roofing

All roofing work can be divided into 3 main groups:

• Procurement. This stage includes selection, sorting or cleaning, cutting of rolled materials. Roofing elements are made from sheet steel, slate is cut, and mastics are prepared.
• Preparatory. The base for the roof is fully prepared.
• Basic. Roofing materials are laid, secured to the base, and cared for after installation is completed.

The most vulnerable elements on the roof are the valleys, which form the recessed angle; precipitation accumulates in them at any time of the year. That's why to the device of this element roofing needs to be approached with all responsibility. The valley is a tray with a width of at least 300 mm, made of boards 25 mm thick. It is covered with galvanized, roofing or black painted steel so that its ends extend 200 mm under the roof on all sides.

The chimney is also surrounded by a roofing steel collar. From the ridge side, a sheet of steel needs to be placed under the roof, and from the eaves on top of the roof, the result is a kind of apron. Next to the pipe, the sheet must be placed under brickwork. According to requirements fire safety, the roofing and sheathing must be no less than 140 mm from the pipe, and all wooden elements must be no less than 400-500 mm.

When choosing drainpipes, you should give preference to a diameter of 100-140 mm; they are located at least 120 mm from the wall. If the roof is covered with tiles or asbestos-cement sheets, then drainpipes will be needed to drain the water. Their basis is roofing steel; they are suspended with a slope of 2-3 degrees relative to the corners of the structure.

The same roofing material is also used to cover dormer windows. Carefully separate the junctions between the windows and the roof slope.

The roof is an integral element of every home. When starting construction, repair or even routine maintenance, many owners of private houses are surprised at how complex a system, consisting of many different components, is an ordinary roof. Therefore, before starting work, you should understand each of the components and their purpose. We list the most common roofing elements that are found in most cases.

Typically the roof consists of the following elements:

• skate;
• rough flooring;
• counter-lattice;
• sheathing;
• rafter system;
• truss rack;
• crossbar;
• mother;
• filly;
• eaves.

The roof may have a different design. Sometimes there are additional elements, and some roofs are built according to a simplified design. But usually all these components are used during construction. Now let's talk about each of them in more detail.

Horse

The skate is the most top element, covering the joint between the roof slopes. Most often found on gable roofs. But sometimes it can be seen on more complex hipped slopes.

It can be made from various materials, depending on the main roofing material - metal tiles, slate, corrugated sheets, ondulin and other materials.

Rough flooring

It is the base on which it is laid waterproofing material- most often tiles. When using slate and corrugated sheets, some builders prefer to abandon it in order to reduce work time, reduce the load on the rafters, and at the same time reduce the cost of purchasing building materials.

The rough flooring is laid directly on the rafters. Typically made from thick plywood, fiberboard, chipboard or boards.

Counter-lattice and sheathing

The counter-lattice is installed on the rough flooring. The bars that form it are laid across the roof. Its main purpose is to ensure ventilation of the entire under-roof space - between the roof and the sheathing.

The sheathing is installed on top of the counter-lattice. The bars are laid along the roof. The roof itself is laid and fixed onto the sheathing. Thus, the lathing takes the entire weight of the covering and transfers it to the counter-lattice, which, in turn, transfers the load to the rafters.

The perpendicular arrangement of the wooden blocks from which the sheathing and counter-lattice are made allows for the most even distribution of the load.

If ondulin or roofing felt is used as the main roofing material, this greatly simplifies the process. Laying is done directly on top of the rough flooring - intermediate elements of the roof covering are not necessary.

Rafter system and related elements

A rafter is a large cross-section block fixed at a certain angle on the top of the wall and transferring the load from the roof to it.

Rafter truss post is a vertical bar installed between the rafters and the matrix. Its main purpose is to partially relieve the load from the rafters, as well as organize the walls of the attic.

Crossbar - a board connecting paired rafters at the bottom. Thanks to it, the rigidity of the truss increases.

The filly is a board that extends the rafter (or rather, the rafter leg), allowing you to organize the overhang of the roof.

The rafter system consists of all of the above elements. It represents a triangular truss that not only transfers the load from the roof, snow and other things to the wall, but also resists the wind.

The height of the triangle formed by the rafter system depends on the intensity of winds and the amount of snowfall in the region. The stronger the wind, the lower the triangle should be to reduce drag. On the other hand, the higher height makes it easier to remove snow from the roof.

The cross-section of the bars used as rafters depends not only on the type of roof, but also on the amount of snow falling during the winter and the strength of the winds. When designing, it is necessary to take into account both permanent and temporary loads - otherwise, after a heavy snowfall, the rafters may break, which will lead to the complete destruction of the roof.

The roof overhang is the part of the structure that extends beyond the external walls. It allows you to reduce the amount of moisture that gets onto the surface of the walls due to precipitation. Its length should be at least 70-80 cm.

These are the most common roofing elements. Knowing them, everyone can imagine standard roof. But there are also many other elements that are desirable, and in some cases mandatory, when constructing a roof.

What are pass-through elements?

Often home owners need to remove some structures through the roof. It could be the cable TV antenna, ventilation, as well as a pipe from a fireplace, heating boiler or stove.

It is in such cases that special roof passage elements are used. They are made of both metal and clay, which allows you to choose a suitable option for both roofing and metal tiles. Installation is possible during installation of the coating and during repairs. Roofing passage elements are usually installed on the sheathing using self-tapping screws of the appropriate length.

A special, carefully calibrated shape eliminates the possibility of rain or melt water seeping through the cracks usually formed when connecting elements of different shapes.

What do you need to know about roof safety elements?

Of course, if we talk about the structure of the roof, then it is necessary to mention the safety elements of the roof.

First of all, this includes:

• stairs;
• fencing;
• snow retainers;
• walkways.

It’s worth starting with snow guards - according to many experts, they are the most important safety element. Their purpose is to eliminate the possibility of unplanned ice and snow falling off the roof. This problem is especially relevant for our country, most of whose regions are located in rather difficult climatic zones. Heavy snowfalls and significant daily temperature changes often lead to very unpleasant consequences.

For several heavy snowfalls alternating with warm ones, on sunny days and on cold nights, a mixture of snow and ice weighing several tons can form on the roof. Often, under its weight, this mass slides off the roof, especially if ondulin, roofing felt without powder, corrugated sheets or metal tiles are used as the main covering.

A block of snow and ice can break a car, and if it falls on a person, at best, he will suffer fractures. Snow guards made in the form of mesh, slats or tubes prevent snow from falling off the roof.

Guardrails are necessary to ensure the safety of the person climbing onto the roof. If a home owner needs to remove snow, adjust an antenna, or perform other work, there is always the risk that he will fall - due to dizziness or a gust of wind. But the fence allows you to almost completely eliminate such a danger.

To easily move around the roof by climbing onto it using an extension ladder, causing minimal damage, they are installed special stairs. They make it easy to climb onto the ridge, while at the same time distributing the load from the human body over a large area, preventing damage to the roofing material.

Finally, the transition bridges. They are a profile with teeth, made of sheet metal. The special shape eliminates the possibility of the bridges becoming clogged with snow. Installed along the roof, they make it easy to reach the desired place, not only distributing the load over its entire area, but also reducing the risk of slipping.

As you can see, a conventional roof has significantly more complex circuit than it might seem at first glance. But still, having studied various elements, their location and purpose, every reader can easily understand its structure. This will greatly simplify the repair, and, if necessary, the design of a new roof.

Useful video about roofing elements

Installation of a gable roof is actively practiced in private construction, since it is the simplest and affordable way construction of a reliable roof for the house. This article describes the main stages of installation, which can be performed independently, with a certain skill in roofing work.

Functional features of a gable roof

The structure of a gable roof consists of load-bearing elements (mauerlat, rafter system) and enclosing elements (roof). A gable roof (gable) has two roofing surfaces located at a certain slope to the outer walls of the building, which ensures natural drainage of moisture from melted snow and rainwater. According to SNiP, the angle of inclination of such a roof should be more than 5°.

The choice of roof slope angle is influenced by:

• type of finishing material;
• architectural features of the building;
• climatic conditions of the construction area.

The construction of a gable roof with a large angle of inclination is usually practiced when relatively lightweight roofing materials are used and in regions without large wind loads, since the pitched roof of a building is a sail. In addition, a steep pitched roof is a practical option for areas with high rainfall - rain moisture is quickly and successfully removed from it, and accumulated snow slides down under its own weight.

Low-slope roofs experience minimal wind loads, but are very sensitive to snow loads. To avoid destruction of the structure under load from snow masses, in winter period The roof should be cleaned regularly.

In private construction, gable roofs are most often erected with an angle of inclination from 35 to 60°. This is the best option in terms of the ratio of roof resistance to atmospheric loads and reasonable costs for materials for installing the rafter system, as well as arranging the roofing pie.

Installation of a gable roof begins with the installation of a mauerlat or floor beams, depending on the type of rafter system chosen. The Mauerlat acts as a foundation for the roof structure. It is this that allows you to evenly distribute the load (the weight of the rafter system itself, snow and wind loads, the weight of people servicing the roof), transferring it to the building structures of the structure.

Mauerlat is a timber made of coniferous species wood with a cross section of 150×150 mm (most often). When erecting a gable roof, it is mounted on two parallel walls. If the project provides for the installation of layered rafters with a ridge girder on supports, then the Mauerlat beam should also be laid on the middle load-bearing wall.

During construction wooden houses The Mauerlat is not mounted - it is an element for laying on building structures made of brick, foam concrete blocks and other materials. On small buildings The Mauerlat can be attached to the walls using forged wire embedded in the masonry. When building a house, arrangement is practiced monolithic beam with installed fasteners.

To make a beam at the top of the walls, it is mounted wooden formwork, metal reinforcement bars are attached (at least 2 pairs of parallel lines, one above the other). Using wire, studs or anchors are attached to the reinforcement. It is important to install them in increments of no more than 1 meter, strictly vertically. The prepared formwork is poured with concrete.

The length of the stud with a diameter of about 14 mm is determined based on the thickness of the monolithic beam, the thickness of the Mauerlat beam plus one or two layers of roofing felt waterproofing. In this case, when laying the Mauerlat, the studs must be at least 3 cm above its surface so that it is possible to secure the beam using nuts with wide washers.

When preparing to install a monolithic beam, you should determine in advance the installation location of the fasteners for the Mauerlat. The beam can be laid strictly along the axis of the beam or with a shift towards the inner or outside walls. To secure the Mauerlat, you need to make holes for the studs.

The Mauerlat is mounted at least 5 cm from the outer edge of the wall.

If the roof frame is planned to be made of metal elements, a channel or I-beam metal profile can act as a Mauerlat.

Rafter system with hanging rafters can be installed without a power plate. In this case, the lower parts of the rafter legs are attached to the floor beam, which is laid across the walls. The beam acts as a tie and provides rigidity to the truss. Construction of a gable roof using this principle is usually used when constructing buildings with a small span, most often from timber or logs. It is not recommended to install support beams on walls made of piece materials, since a point load can destroy building structures.

Gable roof rafter system

The rafter system includes the rafters themselves (rafter legs), as well as a number of other elements, the installation of which is necessary to ensure structural rigidity:

• crossbars;
• runs (including ridge runs);
• racks;
• lying down;
• spacers;
• struts, etc.

Rafter systems can be mounted from wood or metal, or a combination of both types of materials.

Designing a rafter system is an important stage in preparation for construction. Errors in the design can lead to the roof collapsing over time under the influence of operational loads. On the other hand, having designed an excessive safety margin for the roof frame, you will have to spend extra money on its construction.

The design of the rafter system of a gable roof is based on the most stable and rigid geometric figure - a triangle. When installing rafter systems of simple design, the rafters are made of timber with a cross-section from 40×150 mm to 100×250 mm. The choice of a specific value depends on the following factors:

• installation step;
• rafter leg length;
• calculated load value.

In turn, the installation step of the rafter legs is influenced by the type of roofing pie - if a warm roof is to be installed, then this parameter is selected taking into account the width of the roll or sheet insulation.

Types of rafter structures

When considering how to build a gable roof, you need to pay attention to the specifics of constructing rafter systems various designs– with hanging and layered rafters. Rafter legs are the main element of the frame of a gable roof. They serve as a support for the roofing pie. Hanging rafters do not have intermediate supports and rest only on the walls of the building. Layered rafters have additional support points.

A truss, assembled from two rafter legs and a lower tie or an upper crossbar, is a structure that works in compression and bending. The bursting effect from the rafter legs mounted at an angle is compensated by the horizontal lintel. The higher the tie is mounted, the stronger and more rigidly one should be secured. This design allows you to cover even wide spans.

The upper part of the hanging rafters can be attached in various ways. The rigid fastening of the upper ends of the rafter legs is reinforced with the help of overhead elements made of wood or metal. When attaching the rafter legs to the mauerlat, a cutout (saddle) is made on the lower part of the rafter, after which the element is rigidly secured with nails and twisted wire. If rafters are installed on a floor beam, a stop is cut into the beam to prevent movement, and a single or double tooth is cut into the rafter. Installation is carried out using various metal fasteners.

There is no cutout in the Mauerlat timber so as not to weaken the load-bearing capacity of the roof support.

A roof frame with layered rafters is installed if the building has a middle load-bearing wall or columnar supports. The span between the supports should be no more than 6.5-7 meters. The width of the floor can be increased by installing additional supports: up to 11.5-12 meters with one additional support and up to 15-15.5 meters with two. To increase the rigidity of the rafter system and expand the opening between the supports, you should install a rack with struts under the ridge girder. The load on the roof is transferred by the middle part of the rafters to the internal supports, and by the lower ends to the external walls.

Installation of a rafter system with layered rafters is somewhat simpler than assembling and installing roof trusses. After installing the ridge girder on the gables of the building or special racks, the rafters are attached to it with the upper part.

In some cases, it is advisable to use both layered and hanging rafters when installing the roof frame.

The construction of the rafter system should be carried out using quality material to ensure the longevity of the roof. The lumber must have a strict geometric shape; wood defects are not allowed. To prevent wooden elements from warping after installation, the material must be well dried. Before installation, it is necessary to treat the prepared parts with a fire-retardant agent.

Roofing pie device

The question of how to properly build a gable roof, in particular, is related to the competent execution of the roofing pie. The functionality of the design, its ability to provide reliable protection buildings from external influences.

When installing the roof, it is important to follow the designed pitch of the sheathing, having previously installed a counter-lattice to create a ventilation gap for the roofing pie. To ensure the necessary air circulation in the under-roof space, install ventilation duct in the ridge part, ventilation holes are provided in the filing of the eaves overhangs.

Particular attention is paid to reliable waterproofing of the roof, otherwise moisture condensed on wooden elements can cause rotting of the structures. If the attic of a gable roof is intended to be used as a living space, it is necessary to provide reliable insulation and roof vapor barrier.

To ensure the strength and durability of a gable roof, you should carefully approach the development of the project, the choice of materials and compliance with the work technology.

Installation of a gable roof, how to build it correctly, construction

We learn how to install a gable roof with our own hands. In this article you will learn how to properly build a gable roof and where its construction begins.

How the design of the rafter system works, which one is better to choose

The roof structure is considered the most complex component of a residential building in terms of design and installation. The roof is exposed to wind, precipitation and cold, therefore it must be airtight and durable to create comfortable living conditions. The main part of the roof is the rafter system, with the help of which the shape of the structure is created and set optimal angle tilt and waterproofing material is attached. The number of elements of the rafter system, as well as their location, is determined by the configuration of the roof.

Purpose of the rafter system

The rafter system is a certain number of supporting elements that create the geometry of the roof and frame, which gives rigidity to the roof structure and the desired slope. The main parameters of the components of the rafter system and their location are determined taking into account permanent and temporary loads.

In general, the rafter system is assigned the following tasks:

• Creating the shape and angle of inclination. The location of the rafter legs determines the shape of the roof, hence the number of gables and slopes. In addition, with the help of these elements, the angle of inclination of the slopes is formed for the rapid removal of snow, melt and rain water.
• Uniform distribution of the roof load on load-bearing walls Houses. The rafters of the system are interconnected and distributed in the structure so that the weight of the roofing and snow mass is evenly transferred to the building frame, without skewing or deformation of the structure.
• Creating conditions for normal ventilation and protection from moisture. The roof frame is assembled in such a way that air circulates freely in the under-roof space, and the material itself is reliably protected from condensation accumulation.

In addition, the rafter system serves as the basis on which the waterproofing material and lathing for the finishing coating are attached.

With the correct design of the rafter system, the roof will be reliable and durable and will last a long time. According to experts, a well-built frame has higher value Therefore, there is no need to save at this stage. Therefore, it is best to entrust the design of the roof and its installation to professional craftsmen.

Features of choice

The rafter system of a building consists of a specific set additional elements and has its own level of installation complexity. The number of auxiliary parts is determined taking into account the loads from the roofing material and some environmental factors.

When choosing the type of rafter system, you should pay attention to the following factors:

• Features of the climate of the area where construction is planned. It is possible to protect the roof from destruction during snowfalls or heavy rainfall only if the average annual amount of precipitation is correctly calculated. The optimal roof option in snowy regions is a steep slope.
• Wind load. The optimal design option is selected based on the wind rose at the construction site and the average speed of air gusts. In windy regions, slopes are made flatter.
• Use of attic space. Creating a living space under the roof has great importance when choosing the shape of the rafter system.
• Finish used. In order for the roofing covering to perform its functions to the maximum, you need to choose the right angle of inclination of the slope, taking into account the shape and method of fastening the material.
• Financial opportunities. Installation of the roof structure requires large financial investments Therefore, you need to choose the type of roof in accordance with the construction budget.

Types of rafter construction

No roof is complete without a rafter system. The quality of the roof structure largely depends on what is included in the roof truss system. Vertical supports, horizontal ties and rafter legs provide a reliable foundation and support for the roofing. To make the frame, it is necessary to use lightweight materials that do not load the frame at home. They must be durable, with high load-bearing capacity and good resistance to negative natural phenomena.

The most common options are:

• Wooden frame. This rafter system has low weight and good strength, and the natural origin of the material ensures safety for residents and the environment. The frame is assembled from bars with a cross-section of 10*10 cm or 15*15 cm or boards 5*15 cm. Among the disadvantages of wood, poor resistance to moisture can be noted. In addition, the large length of the products contributes to their bending under their own weight.
• Metal rafter system has a high cost, but during installation large area slopes and the use of heavy roofing materials, it becomes indispensable. The metal profile has a high load-bearing capacity, which allows you to increase the distance between structural elements without reducing the strength characteristics. The only drawback of the metal is its poor corrosion resistance. To solve the problem in this case, metals that are resistant to this phenomenon are used.

Structural elements and details

All elements of the rafter system are interconnected. Thanks to this, the structure has rigidity and the necessary strength, and the weight from the roofing is evenly distributed across the load-bearing walls and partitions. The presence of certain structural elements, their cross-section and location depend on the selected roofing material, the angle of inclination of the slopes and the purpose of the attic space.

The main details of the rafter system are the following:

• Mauerlat. This element is a rafter beam located on the top row or crown of the load-bearing walls of the house. For its manufacture, coniferous wood is used, which is hard and durable. The Mauerlat is attached metal studs or anchor bolts.
• Sill. This element, made of timber, is located on the internal load-bearing partitions. The bench serves as a support for the posts, which are necessary to support the skate.
• Racks- these are supports located vertically along the entire length of the beam and supporting the ridge or the central part of the truss.
• Rafters located at a certain angle to the base of the roof. The support for the rafter legs is the mauerlat and ridge beam.
• Bolt and tightening– necessary horizontal elements for paired connection of rafter legs. The crossbar tightens the rafters directly under the ridge girder, the tie rods are slightly lower.
• Struts. These elements are placed at an angle to the rafter leg to prevent deflection. The upper edge of the brace rests against the rafter, the lower edge against the rack or tie.

To construct a simple rafter system design, it is enough to use a mauerlat, ridge beam and rafters. Increasing the level of complexity leads to the use of additional elements that make the structure more durable and resistant to deflections.

Types of rafter system

The architectural features of the structure have a great influence on the configuration of the roof, since the load from the roof structure must be evenly distributed between all load-bearing walls and partitions.

In this regard, the following types of rafter system are distinguished:

• Layered rafter system. In this design, the roof frame rests directly on the load-bearing walls outside and inside the building. Supports on the internal load-bearing partitions are necessary to support the ridge girder. Layered rafters allow you to cover a large area while maintaining strength characteristics.
• Hanging rafter system involves the support of the rafter legs only on the mauerlat. In the upper part, the rafters rest against each other without a ridge. These types of rafters are used when covering structures that do not have internal load-bearing partitions. Rafter truss in this case it has the shape of an equilateral triangle, therefore, stabilizing elements are not required.

The result of choosing the types of rafter system and their structural elements can be a simple roof with one or two slopes, or a more complex one - hip and hip.

Construction of the rafter system: types of rafters, structural elements, roof details, what is included, parts

Construction of the rafter system: types of rafters, structural elements, roof details, what is included, parts

Construction and installation of a wooden rafter system

The roof of the building protects it from cold, rain and wind. This is as important an element as the outer walls and foundation. The rafter system is load-bearing frame roofs. It takes on all the loads: from structures, from snow and wind. To avoid problems during operation, the roof structure of the house must be strong and reliable. Do-it-yourself installation of a rafter system should only be done after careful preparation and study of all the necessary information.

Roof and roofing

Before you start installing the roof of a private house, you need to distinguish between two concepts. Non-professionals are often confused, but builders clearly distinguish between the definitions of roof and roofing. The roof is the entire structure that separates the building from the street above. The roof structure of a private house includes rafters, all other load-bearing elements, thermal insulation material, and roofing.

Rafters - load-bearing roof structures

The roof is the top part of the roof. It is also a roof covering. The installation of a roof requires careful selection of materials. After all, the reliability of waterproofing and comfort of living will depend on it.

System requirements

To properly install a rafter system with your own hands, you must take into account a certain set of rules. Without taking them into account, the structure will not be able to effectively resist negative influences from the outside.

First of all, it is worth considering strength. All elements must withstand the load without destruction. The design of the roof truss system requires preliminary calculation load-bearing structures according to the first limit state. It is he who checks the elements of the rafter system for strength.

The rafter system must be strong and rigid

The second requirement is rigidity. The maximum deflection is taken into account here. The roof structure of a wooden house or any other should not sag too much. The permissible deformations in the middle of the span are equal to the length of this span divided by 200. Before construction begins, the structure of the rafter system must be calculated according to the second group of limit states - for rigidity.

Do-it-yourself roof raftering is done taking into account that the structure has light weight. Otherwise, the load on the walls and foundations increases greatly. It is for this reason that wood has become widespread as a base material. The wooden rafter system has sufficient strength, but weighs relatively little. Attention should be paid not only to the roof structure, but also to choosing the right roofing material. It shouldn't be too heavy. Ceramic tiles have lost their popularity not only because of the cost, but also because the roof of the house, its walls and foundations must be reinforced to accommodate it.

Weight of roofing material for wooden truss structure shouldn't be too big

Special requirements are placed on the quality of the material. Manufacturing wooden elements should be made only from good raw materials. It is worth considering the following recommendations:

• For the main elements, grade 1 or 2 wood is used. Grade 3 can only be used for sheathing and other small parts.
• It is recommended to make rafter structures for pitched roofs from coniferous trees. They are more resistant to rot and other problems because they contain resin. With the same cross-section, the permissible span for hardwood will be less.
• Before starting work, all elements must be treated with an antiseptic. This stage of preparation allows you to prevent many troubles in the future. You can also treat the wood with fire retardants if desired. This will increase fire resistance.
• It is better to purchase wood from northern regions, which is prepared in winter. This material is of the highest quality.

Parts of the structure

The rafter system diagram includes many elements. To understand drawings and correctly perceive information, you need to know at least the basic ones. So, what is the roof made of?

Ridge, cornice and slopes - the main part of the roof

First of all, these are the ridge, cornice and slopes. These elements are the main parts. The ridge is the topmost part of the structure. Cornice or overhang - bottom. Slopes are inclined surfaces that are located between the ridge and the cornice.

The construction of a rafter system requires knowledge of load-bearing elements. These include:

• Mauerlat - timber that is laid along the edge of the walls of a building. The Mauerlat is needed to evenly transfer the load from the rafter legs, which are supported pointwise. Typically, timber with dimensions of 150x150 mm or 200x200 mm (for large buildings) is used for its manufacture.
• Rafter legs are inclined beams that transfer the load from the roof's own weight, snow and wind to the mauerlat. Such beams are usually installed from the ridge to the eaves. But when constructing a hip roof, elements appear that have only one of the specified points. They are supported on a ridge or on a cornice. Such details are called spigots. They usually have the same cross-section as the rafters. In fact, sprigs are rafter legs cut off on one side.
• Purlin - a beam on which roof elements rest. The purlin can be installed under the racks. Another option is a ridge girder (crossbar). The rafters rest on it at the top point. The cross-section of the purlin depends on its span, usually 200x200 mm.
• Sloping legs are only needed for hip roofs. They are diagonal rafters resting on the Mauerlat at the corners. The cross-section is assumed to be enlarged, usually 150x200 or 100x200 mm.
• The design of a wooden roof requires the presence of puffs, struts and racks. They are designed to reduce the load on the main elements. When building a house with your own hands, it is important to remember that the racks cannot be supported on the floor span. Installation is only possible on underlying walls or on purlins spanned between walls. Such elements can be mounted on the ceiling only if it is designed for such a load and reinforced in the required area.
• The lathing is needed to make a base for the covering. For metal tiles and seam roofing, the sheathing can be sparsely made of boards 32-40 mm thick. For bitumen shingles, you need a solid base made of boards 25-32 mm thick or moisture-resistant plywood.
• In order to make the cornice overhang, install fillies. They become an extension of the rafters. The filly is attached to the rafters for a length of at least 1 m. The cross-section of the element is usually taken to be 50x100 mm.

Load-bearing elements of a hip roof

Another element of the rafter system is a truss. This is a one-piece structure that consists of rafters, tie rods, struts and racks, rigidly connected to each other. The farm has triangular shape, and inside it is divided into several smaller triangles, which provides it with good stability.

Roof shapes

Pitched roofs come in different shapes. It is worth highlighting here:

• single-pitched;
• gable;
• hipped (tent and hip);
• broken

The most common are gable and hip roofs

The most common option is a gable or hipped hip roof. The first requires the construction of pediments. Broken lines are relevant when constructing an attic. At first the rafters go at a steep angle, and then at a smaller one. This technology allows you to raise the ceiling of the attic room. We also recommend reading about the rafter system for a half-hip roof.

Types of rafters

There are two designs:

• with layered rafters;
• with hanging rafters.

Installing a roof on a wooden house is only possible using the former. This is caused by two rules:

• hanging rafters must be firmly attached to the mauerlat;
• in a wooden house, the rafters must be hinged to the mauerlat.

These two statements contradict each other, so the rafter system of a wooden house can only contain layered elements.

Only layered rafters are installed in a wooden house

Layered beams are elements that rest on the Mauerlat at the lowest point and on the ridge girder at the top. This allows you to reduce the horizontal thrust that acts on the walls when the rafters try to move apart and take a horizontal position. Elements can be reinforced with racks or struts. In this case, contractions can be placed through one pair of legs.

Hanging tanks are supported only at the lowest point on the Mauerlat. At the top they just rest against each other. To prevent the system of wooden elements from moving apart, tightening must be done. It is better to install them on each pair of legs. This option is characterized by a strong thrust effect on the external walls, but it allows you to get more free space inside the attic.

Connections

Before you make a rafter system with your own hands, you need to carefully study the nodes. To build your home, you shouldn't save time or money. Only in this case the result will please you for many years.

Main rafter connection units

The fastening points of the roof truss system, which deserve special attention, are represented by the following:

• fastening the Mauerlat to the wall;
• fastening the rafters to the mauerlat;
• fastening the rafters at the top point;
• splicing rafters along the length.

Mauerlat to the wall

This node can be performed in several ways. The choice largely depends on the wall material. The construction of a building made of brick, block or concrete allows the use of the following methods:

• on the wire;
• on staples;
• on stiletto heels;
• on the anchor with the device monolithic belt along the edge of the wall.

Connecting the Mauerlat to the wall during construction brick buildings performed using anchors

At wood construction The upper crown of the wall acts as a mauerlat. It is connected to the previous ones using a dowel. In a frame house, the mauerlat is the top frame of the walls. It is fixed to the frame posts by cutting and metal corners with holes for self-tapping screws. Read more about attaching the Mauerlat to the wall.

Rafters to the mauerlat

Fastening is carried out in two ways:

• rigid for buildings made of brick, concrete or concrete blocks;
• hinged for wooden houses.

Rigid fastening can be with or without a notch. It is recommended to do the cutting on the rafters, and not on the mauerlat, since this weakens it. In both cases, the leg is rigidly fixed with nails, screws, staples or metal corners.

With rigid fastening, it is better to make a notch on the rafters and fix the structure with fasteners

For hinged fastening, a special part is used - a slide.. They allow the beam to move without obstacles when the walls of the building shrink.

The hinged connection allows the beam to move

Additionally, the rafter legs are attached to the wall. This is necessary to prevent the roof from being blown off by the wind. For fastening, use a twist of two wires with a diameter of 4 mm, fixed to the wall with an anchor or a ruff. In a wooden house, twisting can be replaced with staples. Fastening is carried out on each beam or through one.

At the ridge level

The layered elements rest on a ridge girder with a notch. Additionally, a board overlay is made on both sides. An overlay is also needed for hanging elements. It can be wooden or metal with holes for screws.

The ridge girder and rafters are connected using a notch

Splicing rafters

There are several methods for splicing roof rafters with your own hands. The choice between them largely depends on the experience of the master. The splice point is located at a distance of 0.15 span lengths from the support. In this case, not only the ridge girder and the Mauerlat are considered supports, but also the struts and racks.

Splicing rafters along the length

There are five ways:

To build a high-quality roof, you need to carefully study the technology, choose the right type of rafters and methods of connecting elements into important nodes. This is especially important when building a rafter system with your own hands.

Roof truss system for a private house: design and installation

How to do it right wooden roof private house. Rafter system: structural elements, rafters, fastening points and do-it-yourself installation.

Types of gable roof truss system: for small and large houses

Each roof is based on a large number of beams, rafters, posts and purlins, which are collectively called the rafter system. Over the centuries-old history, many types and methods of its organization have accumulated, and each has its own characteristics in the construction of nodes and cuts. Let's talk in more detail about what the rafter system of a gable roof can be and how the rafters and other elements of the system should be attached.

Design of a gable roof truss system

In cross-section, a gable roof is a triangle. It consists of two rectangular inclined planes. These two planes are connected at the highest point into a single system by a ridge beam (purlin).

Gable roof diagram

Now about the components of the system and their purpose:

• Mauerlat is a beam that connects the roof and walls of a building, serves as a support for rafter legs and other elements of the system.
• Rafter legs - they form the inclined planes of the roof and provide support for the sheathing under the roofing material.
• Ridge purlin (bead or ridge) - combines two roof planes.
• The tie is a transverse part that connects opposite rafter legs. Serves to increase structural rigidity and compensate for thrust loads.
• The beds are bars located along the mauerlat. Redistribute the load from the roof.
• Side purlins - support the rafter legs.
• Racks - transfer the load from the purlins to the beams.

There may still be fillies in the system. These are boards that extend the rafter legs to form an overhang. The fact is that to protect the walls and foundation of the house from precipitation, it is desirable that the roof ends as far from the walls as possible. To do this, you can take long rafter legs. But standard length 6 meters of lumber is often not enough for this. Ordering non-standard is very expensive. Therefore, the rafters are simply extended, and the boards with which this is done are called “fillies”.

There are quite a lot of designs of rafter systems. First of all, they are divided into two groups - with layered and hanging rafters.

The difference in the design of layered and hanging rafters

With hanging rafters

These are systems in which the rafter legs rest only on the external walls without intermediate supports (load-bearing walls). For gable roofs, the maximum span is 9 meters. During installation vertical support and the strut system can increase it up to 14 meters.

The good thing about the hanging type of gable roof rafter system is that in most cases there is no need to install a mauerlat, and this makes the installation of rafter legs easier: there is no need to make cuts, just bevel the boards. A lining is used to connect the walls and rafters - wide board, which is attached to studs, nails, bolts, crossbars. With this structure, most of the thrust loads are compensated, the impact on the walls is directed vertically downwards.

Types of rafter systems with hanging rafters for different spans between load-bearing walls

Gable roof rafter system for small houses

There is a cheap version of the rafter system when it is a triangle (photo below). Such a structure is possible if the distance between the external walls is no more than 6 meters. For such a rafter system, you can not make calculations based on the angle of inclination: the ridge must be raised above the tie to a height of at least 1/6 of the span length.

But with this construction, the rafters experience significant bending loads. To compensate for them, either rafters of a larger cross-section are taken or the ridge part is cut in such a way as to partially neutralize them. To give greater rigidity, wooden or metal plates are nailed on both sides at the top, which securely fasten the top of the triangle (also see the picture).

The photo also shows how to extend rafter legs to create a roof overhang. A notch is made, which should extend beyond the line drawn from interior wall up. This is necessary to shift the location of the cut and reduce the likelihood of the rafter breaking.

Ridge knot and fastening of rafter legs to the backing board with a simple version of the system

For mansard roofs

An option with the installation of a crossbar - used when organizing a living space under the roof - an attic. In this case, it serves as the basis for lining the ceiling of the room below. For reliable operation of a system of this type, the crossbar cut must be hingeless (rigid). The best option is in a semi-frying pan (see picture below). Otherwise, the roof will become unstable to loads.

Rafter system of a gable roof with a raised tightening and a crossbar insertion unit

Please note that in this scheme there is a Mauerlat, and the rafter legs must extend beyond the walls to increase the stability of the structure. To secure them and dock them with the Mauerlat, a notch is made in the form of a triangle. In this case, with an uneven load on the slopes, the roof will be more stable.

With this scheme, almost the entire load falls on the rafters, so they need to be taken with a larger cross-section. Sometimes the raised puff is reinforced with a pendant. This is necessary to prevent it from sagging if it serves as a support for ceiling cladding materials. If the tie is short, it can be secured in the center on both sides with boards nailed to the nails. With a significant load and length, there may be several such belays. In this case, too, boards and nails are enough.

For large houses

If there is a significant distance between the two outer walls, a headstock and struts are installed. This design has high rigidity, since the loads are compensated.

Gable roof rafter system for long span and ridge and rafter cutting units

With such a long span (up to 14 meters), it is difficult and expensive to make the tie in one piece, so it is made from two beams. It is connected by a straight or oblique cut (picture below).

Straight and oblique cut for connecting the tie

For reliable joining, the connection point is reinforced with a steel plate mounted on bolts. Its dimensions must be larger than the dimensions of the notch - the outermost bolts are screwed into solid wood at a distance of at least 5 cm from the edge of the notch.

In order for the circuit to work properly, it is necessary to make the struts correctly. They transfer and distribute part of the load from the rafter legs to the tie and provide structural rigidity. Metal pads are used to strengthen connections

Fastening struts for a rafter system with hanging rafters

When assembling a gable roof with hanging rafters, the cross-section of lumber is always larger than in systems with layered rafters: there are fewer load transfer points, therefore each element bears a greater load.

With layered rafters

In gable roofs with layered rafters, the ends rest on the walls, and the middle part rests on load-bearing walls or columns. Some schemes push through the walls, some don't. In any case, the presence of a Mauerlat is mandatory.

The simplest version of layered rafters

Non-thrust schemes and notch units

Houses made of logs or timber do not respond well to thrust loads. For them they are critical: the wall may fall apart. For wooden houses, the rafter system of a gable roof must be non-thrust. Let's talk about the types of such systems in more detail.

The simplest non-thrust rafter system diagram is shown in the photo below. In it, the rafter leg rests on the mauerlat. In this version, it bends without pushing the wall.

A simple non-braced gable roof system with layered rafters

Pay attention to the options for attaching the rafter legs to the Mauerlat. In the first, the support area is usually beveled, its length being no more than the section of the beam. The depth of the cut is no more than 0.25 of its height.

The top of the rafter legs is laid on the ridge beam, without fastening it to the opposite rafter. The structure results in two pitched roofs, which in the upper part are adjacent (but not connected) to one another.

The option with rafter legs fastened at the ridge part is much easier to assemble. They almost never push against the walls.

Option for attaching rafters without bracing to walls

To operate this scheme, the rafter legs at the bottom are attached using a movable connection. To secure the rafter leg to the mauerlat, one nail is driven from above or a flexible steel plate is placed from below. See the photo for options for attaching rafter legs to the ridge girder.

If you plan to use heavy roofing material, you need to increase bearing capacity. This is achieved by increasing the cross-section of the rafter system elements and strengthening ridge knot. It is shown in the photo below.

Reinforcing the ridge assembly for heavy roofing material or for significant snow loads

All of the above gable roof schemes are stable in the presence of uniform loads. But in practice this practically never happens. There are two ways to prevent the roof from sliding towards a higher load: by installing a screed at a height of about 2 meters or by struts.

Options for rafter systems with contractions

Installing contractions increases the reliability of the structure. In order for it to work properly, it needs to be secured to them with nails at the places where it intersects with the drains. The cross-section of the timber for the scrum is the same as for the rafters.

Schemes of rafter systems for gable roofs with contractions

They are attached to the rafter legs with bots or nails. Can be installed on one or both sides. See the figure below for attaching the screed to the rafters and ridge girder.

Attaching the screed to the rafters and ridge beams

In order for the system to be rigid and not “crawl” even under emergency loads, it is enough to ensure a rigid fastening in this option ridge beam. In the absence of the possibility of its horizontal displacement, the roof will withstand even significant loads.

Layered rafter systems with struts

In these options, for greater rigidity, rafter legs, also called struts, are added. They are installed at an angle of 45° relative to the horizon. Their installation allows you to increase the span length (up to 14 meters) or reduce the cross-section of beams (rafters).

The brace is simply placed at the required angle to the beams and nailed on the sides and bottom. An important requirement: the strut must be cut accurately and fit tightly to the posts and rafter leg, eliminating the possibility of it bending.

Systems with rafter legs. There is a spacer system on top, a non-spacer system on the bottom. The correct cutting nodes for each are located nearby. Below - possible strut mounting schemes

But not in all houses the average load-bearing wall is located in the middle. In this case, it is possible to install struts with an angle of inclination relative to the horizon of 45-53°.

Rafter system with off-center vertical girder

Systems with struts are necessary if significant uneven shrinkage of the foundation or walls is possible. Walls can settle differently on wooden houses, and foundations can settle on layered or heaving soils. In all these cases, consider installing rafter systems of this type.

System for houses with two internal load-bearing walls

If the house has two load-bearing walls, install two rafter beams, which are located above each of the walls. Beams are laid on intermediate load-bearing walls, the load from rafter beams transmitted to the beds through the racks.

Systems with rafter beams

In these systems, a ridge run is not installed: it provides expansion forces. The rafters in the upper part are connected to one another (cut and joined without gaps), the joints are reinforced with steel or wooden plates, which are nailed.

In the upper non-thrust system, the pushing force is neutralized by the tightening. Please note that the tightening is placed under the purlin. Then it works effectively (top diagram in the figure). Stability can be provided by racks, or joints - beams installed diagonally. In the spacer system (in the picture it is below) the crossbar is a crossbar. It is installed above the purlin.

There is a version of the system with racks, but without rafter beams. Then a stand is nailed to each rafter leg, the other end of which rests on the intermediate load-bearing wall.

Fastening the rack and tightening in the rafter system without a rafter purlin

To fasten the racks, 150 mm long nails and 12 mm bolts are used. Dimensions and distances in the figure are indicated in millimeters.

Gable roof rafter system: device, components

A significant part of private houses are covered with a gable roof. To support it, you need a correctly selected rafter system and well-executed components.

Thanks to modern materials, new methods of arranging their own homes are opening up for developers. For example, quite recently a flat roof was some kind of incomprehensible and impractical object of private construction, but after manufacturers of roofing materials began to produce better products, this opinion changed dramatically. Today, some types of flat roofing can accommodate a workshop, garden or even a swimming pool on its surface.

Characteristics of a flat roof

The whole flat roof idea came to Russia from Western countries, but the designers could not even think that residents of the CIS countries would be hostile to the innovation. The vast majority of people are simply accustomed to seeing gable roofs as protection from the weather, because this type has already been tested for thousands of years and why create something new? The factory owners were in solidarity with this outrage and also did not want to accept the new product. Everything would have remained in its original place if not for advertising. It was thanks to her that people began to look at the flat roof as a more profitable alternative. After all, its construction requires a lot less funds

and time, but the result is the same.

Of course, if you lack finances, your home will be overly simple, but if you use design services, the appearance of the building will be simply stunning.

• The composition of a flat roof includes quite a few materials:
• Base. It can be either reinforced concrete or metal profiled sheet
• Bitumen roll materials are used as a vapor barrier material Thermal insulation flat roof must be distinguished by its rigidity. These requirements are met mineral slabs
• or foam plastic, expanded clay, screed

The waterproofing layer can be created from bitumen roll materials, polyvinyl chloride membranes and various mastics

The layers described above can be swapped with each other, this will depend on the need to use the base. I will write about this below.

Slope on a flat roof Despite the fact that the roof is called flat, it must have a certain slope, which is taken from the range of 1-5 degrees. By creating a certain slope, you will not have to climb onto the roof every time after rain and remove water from the surface; it will be removed naturally. In addition, the accumulation of moisture on the roof plane greatly increases the risk of leakage, and

Regardless of the coating used, it will quickly collapse if the water remaining on the surface repeatedly changes its state of aggregation. Deflection is the only acceptable solution to this problem. To organize it, it is necessary to select materials that match the roofing structure.

The most appropriate product for leveling is considered to be a concrete mixture combined with polystyrene. This method is very easy, so even a person far from construction can give a slope to the roof. It is worth noting that concrete is far from a lightweight product and before laying it on the roof you need to check the calculations.

If for some reason you cannot purchase polystyrene foam, then as an alternative, most developers advise using a concrete mixture mixed with perlite or expanded clay. The combination of these materials will create an even greater load on the roof than previous products, but at a cost they are much more profitable.

Another option for creating a slope is the use of monolithic thermal insulation. To bring this method to life, you first need to prepare the surface. Then insulation boards are laid on it and secured with dowels and glue.

When considering the above-described methods for arranging a slope, we can say with confidence that the use of bulk materials will be the most labor-intensive process. But if you want to create a high-quality and durable coating, then you will have to use it.

Functional load

Future residents of private houses can be divided into two categories. The first of them are pursued by economic benefits and such people are looking for a less expensive solution to create their home. As for the latter, in addition to saving, they want to create optimal conditions For comfortable stay. Flat roofs are suitable for both categories, but the used and unused surface will distinguish them.

Unused roof

The unused surface is the most common a variety of flat roofs. Looking at such a roof in section, you can clearly see minimum set materials. Each of them has a specific function and is responsible for the maximum possible load. The most striking feature of this design is its low price, in second place is ease of installation.

Several decades ago, the most suitable coating for an unused roof was fused materials, in particular roofing felt, but modern materials have replaced it over time. Today, increasing preference is given to PVC membranes, because installation work can take place at any time. weather conditions. The membrane product strips are welded by heat welding, which fits the description of safe operation.

Of course, if you want to save as much as possible on installing a flat roof, then the base can be covered with simple mastic, the main thing is to distribute it carefully. The desired result can be achieved by installing a reinforcing mesh. It will not only strengthen the coating layer, but also help distribute it as evenly as possible.

If you don't go to extremes, then the best option The same weld-on waterproofing remains. For example, an old roofing material could serve as a coating for only 5 years, but today's bitumen roll materials can last 20 years without change. Moreover, the price for such products is quite reasonable. In addition to the coating itself, you can carry out the installation yourself, which eliminates the need to hire a team of roofers.

Operable roof

This method of arranging the roofing surface is expensive, but by changing the places of some layers, great opportunities. The installation of a roof in use can take up to long time, so it’s better to work with a partner.

An interesting fact is that most of the residents move from unused roofs to operated ones. This is due to the need to increase usable area land plot, and they really regret not knowing this in the past. Don’t make their mistakes when planning to build a house from scratch; soberly evaluate all the nuances. For example, if you have a large number of friends, then probably someday you will want to invite them to your place and if there is not enough space to relax, you can move to the roof. This practice has long been used in Western countries, but Russian residents still have a negative attitude towards this.

Types of flat roof

So, when you have become familiar with some of the nuances of flat roofs, you can begin to study their types. The roofs under consideration are divided according to their functional load and design features, therefore, two main categories can be distinguished: exploited and non-exploited.

For structural reasons, flat roofs can be:

• With traditional roofing pie
• With inversion
• Breathable
• Greens

Now, let's understand everything in more detail.

Traditional roofing

Such a roof implies a standard placement of all layers of the roofing pie. Usually, Special attention paid to the placement of the waterproofing layer. For usual reasons, it is placed on top of thermal insulation. This method of installation can be found on almost any modern flat roof. By the way, roofing felt has not been used as a waterproofing layer for a long time; greater preference is given to PVC membranes.

IMPORTANT: Traditional roofing tiles cannot withstand even small loads, so this installation method is only suitable for unused surfaces.

The advantages of this roof:

• Simple and clear structure
• The installation process is very fast
• Low cost
• Possibility to create the roof yourself

The biggest disadvantage is that when servicing the roof, it is necessary to build special bridges and ladders in order to ensure that it is safe for the material to move across the surface.

Installation technology

I've already said that installing a traditional roof is very simple, so you don't need to sit and study the construction business before starting work, but to speed up the process, it won't hurt to get an experienced partner.

• Any construction project must begin with preparatory work. Therefore, at this stage it is necessary to create a good, solid foundation. As a rule, these are reinforced concrete slabs. If it has already been laid in advance, then clean the surface from debris and dust.
• Next, we proceed to laying the vapor barrier layer. Film, polypropylene, bitumen and other polymer products are suitable for this. If you need to choose between materials, it is best to give preference to weldable ones. The fact is that they create a high-quality monolithic carpet that has much better waterproofing qualities
• The next layer will be thermal insulation. Nuances, for example, the region of your residence, will help you choose which material to use. In addition, it is necessary to take into account the functional purpose of the building. If this is a bathhouse, then to maintain heat in the room you will have to lay several layers, but if it is a residential building, then you can get by with just one. By the way, mineral wool– the most popular thermal insulation material
• Next, we proceed to installing the bottom layer of waterproofing. For quality roofing Any good roll material will do. All strips are welded together using open flame or heat welding
• The roofing pie is completed by the top waterproofing layer. When choosing a material for this, you should understand that this layer will be affected by aggressive external environment, therefore it must have appropriate protection

There are two ways to attach thermal insulation boards. First glue method, and second - mechanical(using dowels). For reliability, you can use them together.

Inversion roofing

There are a lot of developers using traditional styling after several years they regret it. A roof whose layers are laid using the inversion method is very multifunctional. You can place a workshop on it, create gorgeous garden or just relax with friends. In addition to these additional features, a concrete screed is a good protection, thanks to which your roof will last much longer than usual.

If you look at a cross-section of a flat inversion roof, it becomes clear why it is called that. It's all about the location of the waterproofing layer. It is located at the bottom of the insulation, thereby protecting it from condensation coming from below. It is worth noting that it is very easy to convert a traditional roof into an inversion one. All you need to do is remove the top coat and lay down the layers again, but in a different sequence.

When creating an inversion roof, it is necessary to take into account the degree of possible loads.

1. Minimum load. The structure of such a roof will include very few materials: a standard pie and a light topcoat made from a bitumen roll product. The roof surface can be equipped as a summer deck, but no more than that
2. Medium loads mean location on the surface of a roof, workshop, green garden or evening relaxation area. When studying the structure of the roof, it can be noted that more layers are used in layers. durable materials with the possibility of their reinforcement. It is best to lay as a finishing coating paving slabs or any other suitable alternative
3. High loads can only be created by massive objects, for example, restaurants, car parking, swimming pools, etc. The structure of this roof is very different from the previous ones. The strongest materials are used here, and reinforcements are installed between the layers. The finishing layer is an ordinary reinforced concrete slab

If you can’t make up your mind in any way, then I can advise you the following. If you do not plan to arrange any parking or the like on your roof, then medium loads will suit you. This way you won’t need to rebuild the building if you need to have a good rest with friends.

Breathable roof

At all times of construction, no matter what modern materials were used, condensation has always been and will be an urgent problem for developers. In some regions of the country, this may not bother anyone, but if you look at the service life of roofs in the central latitude of Russia, you can immediately see that the problem needs to be solved. Increased humidity in the room can provoke the spread of harmful, poisonous fungi, which quickly destroy everything in their path.

Condensation has negative impact not only on the external roof covering, but also destroys it from the inside. For example, if there is a large accumulation of moist air in the attic, it will begin to change its state of aggregation and turn into drops of water, which will be the main reason for the detachment of the roofing from the base.

If we consider pitched roofs, then they are provided with natural ventilation. It works thanks to differences in temperature and pressure, and air changes through specially made holes. As for flat structures, this cannot be done on them. A good alternative to solve this problem is artificial ventilation. It is created by installing special aerators and deflectors. Their number is taken from the ratio 1 piece per 25 square meters. It is worth noting that it does not make sense to install 1 aerator, so there should be at least 2 of them on the roof surface.

The advantages of this roof include the following points:

• Installing aerators and deflectors is very simple; for this you don’t even have to dismantle the covering
• Having installed artificial ventilation, you will pay for it in a few years
• Thanks to air ventilation, you will achieve the maximum possible service life of the roof as a whole.

So that you understand the principle of operation of this system, it is better to explain it in more detail.

Operating principle of aerators

Excessive moisture accumulation can destroy building materials in just a couple of years, so if you choose to install aerators on your flat roof, you will increase its lifespan. Special devices called aerators are fans mounted on pipes various sizes. By the way, the material for creating these same pipes can be metal or plastic. A protective cap in the form of an umbrella must be installed on top of the aerator in order to exclude the possibility of moisture from entering from outside.

The operating principle of this device is very simple; pressure does all the work. The lower collides with the higher and due to this the fans are driven.

As a rule, aerators on flat roofs with simple configurations are distributed evenly. Installation is carried out exclusively at the highest points so that it falls on the joint thermal insulation boards. As you already understand, devices for artificial ventilation can be installed on a finished roof, but by taking care of this in advance you can avoid high costs.

In European countries, when creating a breathable roof, they actively use elements to remove smoke naturally. Interestingly, during a fire you can use them to leave the building and thereby remain safe.

Green roof

I consider the last method of constructing a flat roof to be the most beautiful and interesting. The fact is that after laying all the necessary layers, the surface looks more like a natural area, and not like a roof. This type of roofing came to us from Europe. Residents of Western cities are very actively involved in greening the entire planet, so this type of housing seems to them the most acceptable. As you know, time moves on, and fashion has reached our latitudes, so anyone who wants to follow this trend and create something similar on the roof of their house, read this paragraph very carefully.

The undeniable advantages of green roofing:

• Separate area for recreation. Surely, after working a difficult week, you will want to take a break from the bustle of the city by going into nature. So what could be better than your own roof garden?
• You plan the relaxation area yourself, so you can make it as comfortable as possible
• Gardening helps natural resources restore clean air
• Fertile soil on the roof of a building provides excellent protection from heat and cold throughout the year.
• Very strong sound insulation

IMPORTANT: If you have a desire to apply even a few centimeters of soil to your roof, think about whether it can withstand such a load. There is no room for doubt in construction, so contact a specialist to determine the maximum permissible load.

Green roofing is divided into two types according to its characteristics:

1. Intense. This name indicates that the soil layer can reach significant sizes; as a rule, the limit for such roofs is considered to be 60 centimeters. This amount of soil creates a serious load, so only small shrubs or lawn grass can be grown in such soil. Often such surfaces have several levels in order to create interesting design and save space on a private plot
2. Extensive. The maximum soil layer can be 15 centimeters. The plants grown can be a lawn or individual trees placed in special pots. You can water the soil only at the lawn growth stage. This type of green roof will help create a comfortable corner for relaxation, and caring for it will not be burdensome

I draw your attention to the importance of making calculations. When the soil is laid on the surface, it is loose and dry, but after the first rain it will become compacted and increase in mass many times over. Calculating the maximum permissible load is a difficult task that includes a lot of nuances. To achieve the most accurate results, contact the appropriate specialists.

The principle of a green roof

The principle of laying the elements of a green roof is not much different from creating a standard flat surface. The whole essence of the work is as follows:

• Cleaning the base from various debris and foreign objects
• Waterproofing material is laid on the prepared surface.
• At the next stage, a large amount of extruded foam is poured onto the waterproofing. This material will serve as good protection from the cold
• After uniform distribution of the previous layer, the geotextile is laid, pressing it with bulk material in the form of crushed stone or gravel. Small stones will perform a drainage function
• When the leveling of bulk materials is completed, the plane is covered with a second layer of geotest.
• At the final stage, the required amount of soil is poured and any plants are planted.

With the correct use of a green roof, you can create a chic garden or fruitful vegetable garden in the middle of the bustle of the city. This corner will always calm you down and restore lost strength. It is worth noting that green roof changes for the better not only the owner, but also the environment as a whole. After all, thanks to growing plants, carbon dioxide is processed.

For example, in Japan they even use small plot roofs. If you are not indifferent to this problem, then you should think about creating the same roof. At the moment it’s as easy as shelling pears, the main thing is to do everything correctly.