House with a broken roof. Do-it-yourself sloping roof: calculation and installation

Any owner wants his home to be not only beautiful, but also spacious. But this cannot always be realized with a limited construction area and even construction two-story houses. This problem can be solved by building a house with an attic, and a broken-style roof will help raise the ceilings in the attic and make it a full-fledged room. Naturally, the larger the size of the house, the larger the attic space. So houses 9x7 or 9x8 m will have the largest area of ​​this room. In addition, the design of a broken roof looks very tempting and original from the outside of the house, especially if it is made of high-quality and beautiful roofing materials.

Advantages of erecting a sloping roof

A design of this form is indispensable when deciding to make an attic space residential, as it can raise the ceilings to normal levels.

Regarding the complexity of constructing a sloping roof, the opinions of professionals differ: some say that such houses are difficult to build even from the design stage, for others they are much simpler, but only if the engineering and construction work is done correctly.

By building a sloping roof instead of a gable roof, you can get the following benefits from its presence:

The nuances of a sloping roof and suitable materials

Each project of any house is completely individual and depends on the required dimensions and desires of the customer; buildings with a sloping roof are no exception. A sloping roof can be on a house 8x8, 9x8, 6x6 m and sizes in between. But, there are several universal tips that are best followed during construction:

• The building should not be more than 6 meters wide.
• Roof breaks should form angles of 30 and 60 degrees
• The ceiling in the attic can be raised up to 2.5 meters, and if you make a break higher, then 3.1 m.

Important! If the width of the house is less than 6 meters, then the attic space will not be used effectively, and if it is more than 9 meters, then difficulties may arise with the construction of rafters.

Sometimes when designing a sloping roof, a situation arises that the walls are not exactly rectangular. But when it comes to building rafters, it is important to maintain a rectangular shape. If this can be done, then in the future there will be no problems with the construction of roof slopes.

Since a sloping roof is carried out step by step, that is, all modules are arranged step by step, it can be erected without resorting to the services of heavy construction equipment. When installing a broken-type roof, it is imperative to adhere to the creation of massive rafters and high-quality installation of the roof itself using only the best building materials.

Particular attention should be paid to the material from which the rafters are made. They are mostly mounted from timber, and it is better to use coniferous wood. The material must meet the following conditions:

Important! The durability and reliability of the future roof structure depends on how correctly the material is selected.

It is also very important to treat the material before construction with an antiseptic solution, which will protect the wood from the spread of rot and harmful fungus on its surface. Moreover, such treatment must be carried out periodically even during the operation of the roof.

No less important is treatment with fire retardants - substances with fire-fighting properties. All processing work is carried out only outdoors and wearing gloves, as well as a respirator. Apply the product in a double layer to ensure maximum protection.

In addition to timber for rafters, installation sloping roof will require availability edged boards for arranging sheathing, plywood, in order to connect rafters, fastening materials in the form of staples, screws, studs, brackets and other elements, insulating and waterproofing materials, roofing materials. For high-quality and simple work, you will need special carpentry and carpentry tools.

At the initial stage of construction, when the project is far from even approved, the potential homeowner considers many options of different sizes, number of floors, and layout in search of the most rational option. It has been tested by time, as well as by the experience of thousands of people, that space is used most fully and efficiently in houses with an attic. Thanks to the residential attic space in houses with sloping roofs, the cost of one square meter they are one and a half to two times lower than in two-story dwellings of similar usable area.

However, the traditional triangle-shaped one is completely unsuitable for attic equipment. Since its rather steep slopes conceal the available space, leaving only a narrow strip suitable for comfortable life ceiling height.

Therefore, most often the construction of an attic means that the house needs a sloping roof. This design is technically more complex than that of a conventional gable, so it is very important to understand its structure rafter system, installation features if you plan to do it yourself.

Basic structural elements

The broken roof, shaped like a pentagon with the top point at the ridge, is visually divided into upper and lower parts. In the upper part the slope of the slopes is more gentle, it is no more than 20-300, and in the lower part it is steeper, within 50-60 degrees. To assemble it, a mixed rafter system is used, consisting of hanging and layered rafter legs.

To form the necessary geometry of the slopes and give the structure rigidity, a large number of elements are used, which is why the sloping roof has an impressive weight. The main components of the roof are rafters, mauerlat, floor beams, and additional components are racks, headstock, struts, and tie-downs. All of them are made of solid wood coniferous species, pre-treated with a fire retardant and antiseptic.

• Mauerlat is a square beam placed at the base of the roof to distribute its weight evenly over the load-bearing walls, and also protects the rafters from tipping over.
• Rafters. Rafter legs, made of smooth, reliable boards, form a slope, converging at the ridge. In a sloping roof, the upper rafters are layered, as they have additional support on the posts. And the lower ones are hanging, because they seem to sag between the floor beams and the tie. The distance between the rafters is chosen in the range of 60-120 cm, depending on the weight of the roofing material or the width of the insulation.
• Puff. Also called a transom, a horizontal beam that links the upper rafters to reduce expansion. It also serves as a frame for creating an attic ceiling.
• Racks. Vertical supports made of timber that transfer the load from the layered rafters to the load-bearing walls through the tie. Once covered with plywood, they will become the walls of the attic, so the length of the studs is determined by the desired ceiling height. Although 1.5-1.7 m is sufficient for arranging a living space, a ceiling of 2-2.5 m is considered the most comfortable, which can easily be achieved with a sloping attic roof.
• Grandma. A vertical suspension that connects the skate to the tie, compensating for its deflection.
• Struts. Also known as rafter feet, corner supports that prevent hanging rafters from sagging.

Rules for installing the Mauerlat

Before making a sloping roof, you need to lay a mauerlat in accordance with building regulations. How larger area roof, the greater its weight, the thicker the timber should be. If for small buildings a material with a cross-section of 100x100 mm is sufficient, then for large houses a beam of 200x200 mm is used.

Before installation, waterproofing of the attachment point is carried out; for this purpose, roofing material folded in half or several layers of film are laid. The method of installing the Mauerlat depends on the material from which the house is built. Most often it is installed on a block concrete screed using metal pins.

To prevent the strength of the sloping roof Mauerlat from being lost, as few holes as possible must be made in it. And the location of the studs should be calculated in such a way that they are not located between the rafter legs, and not under them. Otherwise, the insertion holes will be located too close to each other, which can lead to the appearance of cracks, as well as complete rendering of the Mauerlat unusable.

Assembly sequence of the rafter system

Many instructions on how to make a sloping roof do not describe in too much detail the process of assembling the rafter system, the construction of which occurs as follows:

Additional thermal insulation

Since the attic space under a sloping roof is used for residential purposes, it is imperative that it be insulated. Experts recommend using mineral wool on a basalt base in the form of rolls or slabs.

For middle zone In Russia, a layer of insulation equal to 150 mm is sufficient. You will also need a vapor barrier film, a moisture-proof membrane and a frame on which all this will be attached.

On inside counter lathing is being installed on the slopes. For this, a board is used, the width of which is a couple of centimeters greater than the thickness of the insulation, since the insulation should never be compacted.

That is, for a 150 mm layer of mineral wool, a 50x200 mm board is suitable. This gap is also necessary for air circulation, providing natural ventilation. The insulation is laid spaced between the beams of the counter-sheathing, and the inside is sewn up with the selected material.

Construction of gables

Pediment is a part of the wall, limited by the slopes of the roof, and below by a cornice. In a sloping roof it has a pentagonal shape. To build a pediment, it is necessary to strengthen the first truss and supplement the structure with posts to form a frame.

• If there are windows on the pediment, openings will be left for them. The rest of the space is sheathed with an “inch”.
• The gable of a sloping roof can be installed before roofing work or after. The first method is good because the slopes will not make work difficult, and the second is because the geometry of the slopes has already been specified.
• The gable space also needs insulation, which is most often carried out inside.
• Professional roofers recommend using basalt mineral wool or polystyrene foam insulation for thermal insulation of a sloping roof.

The next step is to install the cornice boards around the perimeter of the building. The size of the lumber can be 25x150 mm. Next comes installation time. drainage system, which a sloping roof needs.

It is not difficult to install the structure with your own hands, but after laying the roofing material it will be more difficult. If metal gutter clamps are used, then they need to be fixed directly to the rafters under the waterproofing, and if plastic ones - to the front board.

Construction of sheathing

The sheathing of a sloping roof is a kind of base on which the roof is subsequently laid. It can be solid or lattice depending on the type of material.

1. Solid. They are made from sheets of moisture-resistant plywood, which are laid solidly on the rafters. Used for fastening ondulin, shinglas, slate.
2. Lattice. It is made from unedged boards, which are laid perpendicular to the rafters. It is used when laying metal tiles and corrugated sheets.

It is more convenient to do lathing on a sloping roof if scaffolding is already installed around the perimeter of the house; in any case, they are necessary for constructing the roof. First, a waterproofing film is attached to the rafter legs; a construction stapler is useful for this. The film is laid with an overlap of 10-15 cm. Then the counter-sheathing slats and the sheathing itself are attached. The length of the boards must exceed the length of the roof to form a gable overhang and gable flashing.

Roof decking

The sequence of roofing work on a sloping roof is determined primarily by the selected material. Let's talk about the installation of metal tiles, since they are the most popular in private construction. For installation you need a powerful screwdriver, a tool suitable for cutting metal, a hammer, a tape measure, a marker, galvanized self-tapping screws with a rubber head. First, the sheets of metal tiles are cut, and then installed, starting from the ridge.

Important! The screws should be screwed into the bottom of the pattern wave. Otherwise, the sheet will be deformed, the fastening will become unstable, which is why the roof will “buzz” in windy weather.

• In addition to the roofing material, the sloping roof must be equipped with other important elements: a ridge board, a snow retainer.
• The ridge is installed with an overlap of 10 centimeters on the metal tile on both slopes.

Snow guards serve to prevent snow from melting; it is a small cornice. They are fixed at a short distance from the end of the slopes with self-tapping screws, taking into account the fact that the snow retainers must withstand heavy loads, especially during snowfalls.

Making a broken roof with your own hands will not only allow you to save on wages for a team of workers, but will give you confidence that the processes were carried out correctly, since the construction was carried out in compliance with technology.

Video instruction

When building a big house special meaning It has appearance and roof structure. If we talk about the appearance of the roof, then it can spoil the impression of the house or, on the contrary, give the building a beautiful and unusual look. In addition, modern roof structures make it possible to equip extra room in the attic.

There are many roofing designs, but in this article we will look at how to make one. We will also discuss how to properly treat wood with fire-resistant agents and make a rafter system.

Sloping roof structure

IN Lately More and more people want to increase the interior space of their home without spoiling the appearance of the roof. A sloping roof is perfect for these purposes. It allows you to equip the attic space, making it as comfortable as possible. I would like to immediately note that this type of roof is a very expensive structure, which during construction requires special skills and considerable financial investments. But despite this, this sloping roof is extremely popular.

This design is called a polyline due to its shape and a large number of unusual broken lines. In many cases, the broken structure is a gable roof, with the ability to equip a large attic space. In addition, by arranging a sloping roof, you can easily do it in the attic high ceilings. On a regular gable roof, high ceilings cannot be made due to the high wind load, while on a sloping roof, thanks a large number fractures, wind load is not terrible.

The most popular is the hipped roof shape. Its design allows for the most efficient use of internal space with a relatively small investment. Also, the advantage of a broken structure is that it can be assembled without the use of heavy equipment.

Types of sloping roofs

Broken roofs are distinguished by the number of slopes. For example, there are single-pitched, double-pitched or. Each type of roof is selected depending on the financial capabilities and preferences of the home owner.

The shed roof form is the simplest and cheapest design, which is quite possible to make even on your own. This roof consists of one slope. The disadvantage of a sloping roof is that in most cases it is impossible to equip a large attic or attic space under a pitched roof. Very often, this roofing design is used for outbuildings, sheds or garages.

The gable roof shape is often used for rectangular houses. The design consists of two slopes, which are located opposite to each other. The gable roof is very popular due to its ease of installation and the ability to build a large attic or attic space. Sloping gable roofs are even more popular. An example of this design can be seen in the photo.

The hipped roof shape has four slopes, thanks to which the design has many advantages. Although from a technical point of view this option it is very difficult to do, a hipped roof has a very beautiful view, and also very light weight.

If desired, you can even make a heptagonal roof shape. If we talk about how to build a sloping roof, then before starting construction you need to draw up a project, thanks to which it will be possible to calculate the amount of materials and financial investments.

Mauerlat installation

Before installing the Mauerlat, it is imperative to perform high-quality waterproofing. Roofing felt is perfect for this job. It is best to lay several layers of this material.

After installing the waterproofing, you can begin installing the Mauerlat. Mauerlat is a beam with a section of 150-×150. The rafters on which the entire structure is supported will be laid on the beam. For additional strength of the roof, the Mauerlat is attached to the wall using metal pins.
In order for the made Mauerlat not to lose its strength, it needs to be minimal amount holes.

Wood processing

Before installing the rafter system, you need to treat the wood with antiseptics and fire-fighting agents. To protect wood from fire, there are products that can be applied manually or using a spray gun. When purchasing, you need to consider the type of product. For example, they exist for open and closed areas.

Treating wood with antiseptics protects it from rot, fungus or mold. Water-soluble antiseptics are very often used for construction. They dry very quickly and give the wood good vapor permeability.

Roof angle

In order to build a house with your own hands, you need to calculate the angle of the roof. The angle of the roof is measured in degrees starting from the horizontal line of the slope. Some homeowners, when building their house, neglect this work and determine the angle of inclination “by eye”. But it is worth remembering that an incorrectly selected angle of inclination can lead to the roof covering deteriorating very quickly under the influence of wind or rain.

When choosing the angle of inclination of the roof, it is necessary to take into account the climatic features of the area. For example, in areas with high winds, it is not recommended to build a roof with an inclination angle that is too large. Experts say that by increasing the roof slope by just 30 degrees, the wind load increases by about 5 times. But in areas where it constantly snows or rains, too small an angle of inclination can lead to the fact that the roof will not withstand the snow load or allow moisture to pass through the joints between the roofing material.

Also, to select the angle of inclination, it is necessary to take into account the roofing covering. Each roofing material has its own minimum angle tilt For example, for slate, the optimal slope would be 30 degrees.

Advice! When choosing the angle of inclination of the slope, you should remember that the consumption of roofing material depends on this indicator. Therefore, if you make the slope angle too large, the material consumption will increase significantly.

For the construction of a gable roof optimal angle The slope of the slope will be from 20 to 45 degrees.

Installation of a rafter system for a sloping roof

After installing the Mauerlat, you can install the rafter system, which is made of wood. First you need to install vertical rafters that are attached to the gables. In order for the structure to be smooth, the process must be controlled using building level and plumb line.

The racks must be temporarily secured with spacers. It is necessary to pull the cord between the rafters and install the remaining racks. After this, purlins from boards can be installed on the racks. The purlins must be secured using metal corners and self-tapping screws. After installing the purlins, longitudinal ties can be attached to them, which will connect the parallel posts. More information about the rafter system can be seen in the video, which will look at the construction of the rafter system step by step.

Advice! Before installing the upper hanging rafters, you need to mark the center of the roof. For this work, it is necessary to secure the board in the center of the gable tie and mauerlat. The center of the roof will indicate the top edge of the board. After this, the template base must be attached to the board. Thanks to this, it will be possible to correctly cut the upper rafters.

Installation of lathing under a soft roof

After installing the rafter system, you can begin filling the sheathing. But in order to do it correctly, it is necessary to make high-quality waterproofing. The waterproofing film is installed starting from the bottom of the roof. It is attached with counter-battens to the rafters. It is not recommended to fasten the film with a stapler, since under the influence of condensation the staples will very quickly rust, after which the film will sag and cease to perform its functions.

It is also very important to properly insulate the roof. The insulation will not only retain heat in the house, but will also serve as excellent sound insulation. Mineral wool is often used to insulate roofs. It is very easy to install and is not afraid of rodents.

Advice! It is very important to leave vents between the insulation layer and the roof, which are made to ventilate the space. If ventilation is not done, dampness will appear, which will destroy the constructed roof frame.

It is worth understanding that the sheathing is packed specifically for the selected roofing material. For example, for a profiled sheet it is necessary to fill the sheathing with a distance between the boards of 50-80 cm. But for a sloping roof, a soft roof is perfect. This is a material for which you need to make a continuous sheathing. Although this roofing material is quite expensive, it has excellent sound insulation and a long service life.

For soft roof it is necessary to make a solid base. For this work, plywood, boards or OSB sheets are usually used. It should be noted that the base for a soft roof must be perfectly level. The error should be a maximum of 2 mm. It has been proven that roofing with uneven sheathing lasts much less. In addition, roofing materials often do not hide the shortcomings of the sheathing, but only reveal them.

If the sheathing for a soft roof is made of boards, then the gap between them should not be more than 5 mm. The boards must be installed starting from the roof eaves, moving upward. The boards need to be secured with two self-tapping screws on both sides.

Advice! In order to avoid deformation of the sheathing boards, they must be attached with the rounded side to the wooden frame.

If the sheathing for the soft roof of a broken roof is made of plywood, then during installation it is necessary to leave a gap of 2 mm between the sheets. The reason for this is the thermal expansion of plywood. This material must be secured with rough nails or self-tapping screws. To prevent the heads of the screws from scratching the tiles, they need to be recessed into the surface of the plywood.

Conclusion

As we saw from this article, a broken roof is an excellent design that can make a gray and inconspicuous house unique and unusual. When building this structure, be sure to take into account the opinion of experienced specialists and draw up a detailed roofing project. Also, under no circumstances should you skimp on roofing material. Unfortunately, broken roofs covered with cheap materials such as ondulin very quickly begin to lose their original appearance and leak. But following all the recommendations and purchasing quality materials, the result will not disappoint you.

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A broken roof is sometimes called an attic roof - this type of building roof is one of the most difficult decisions regarding design and construction. Despite this, unusual and original design a sloping roof attracts property owners, and when choosing an option for creating a roof, they prefer it. The construction of a sloping roof, shown in the photo, allows you to get an additional residential or utility floor.

Features of broken roof structure

Mansard roofs, which have four slopes and are classified as sloping roofs, have been very popular in private housing construction in recent years, as they allow the most efficient use of the internal attic space. is excellent choice for those owners who prefer to functionally use every “square” of the house’s area.

A broken roof can decorate any building - it looks more solid and presentable, and when using a certain roofing material, the home has an attractive appearance.

Roofs of broken structures are erected on houses that have sufficient width. The optimal value of this parameter should be approximately 6 meters, otherwise the attic space is difficult to use most rationally, and the rafter structure is difficult to design and make it reliable in operation.

Although support system Such roofs look very impressive, it is quite possible to make it with your own hands: a sloping roof is assembled, as a rule, from individual modular elements on the ground, they are then lifted up and then mounted in place.

Required materials and tools

Before you make a broken roof yourself, you need to prepare materials, tools and some equipment, or rather:

Protection of wooden roof elements

Before assembling a sloping roof (its rafter base), it is necessary to implement a number of preventive measures, relating to the protection of wooden rafters, beams and purlins from possible ignition and rotting processes. Before lifting wooden elements for installation, they are treated with antiseptics and special fire-fighting compounds.

To apply them to wood parts, use a wide flat brush. The product must be used in two doses. After applying the first layer, wait until it dries completely, and then only coat it a second time. This method of preventing rot and fire ensures that protective agents penetrate deep into the wood.

When working with these compounds, the organs of vision and breathing need reliable protection, for which they must use goggles and a respirator.

The use of a spray gun is not prohibited, but the spraying method is undesirable, since in this way it is impossible to ensure high-quality application of impregnation. It is possible to carry out treatment with protective agents against rotting and fire after installation of the rafter structure. True, in this case, you will need to very carefully and carefully treat the joints of the wooden elements with compounds, releasing the clamp from the studs.

Rafter system for sloping roofs

The procedure determining how to make a sloping roof involves the first creation of a rafter structure, which is the basis for installing the roofing.

The rafter system is erected as follows:

Insulation and waterproofing of a sloping roof

When asked how to properly make a sloping roof, experts say that this is impossible without installing waterproofing and insulating layers.

You should use insulation specifically designed for roofing, since this is the only way to achieve the greatest effect from the thermal insulation of the walls and ceiling of the attic room.

A layer of waterproofing and vapor barrier material is laid on top of the rafters, which helps protect the sloping roof from possible leaks and prevents condensation from collecting in the under-roof space and thereby negatively affecting the microclimate of the attic room. The effect of using insulation in the presence of leaks and condensation may also be minimal.

Vapor and waterproofing materials are attached to the rafters using galvanized staples and a construction stapler. Panels waterproofing film laid with an overlap; in extreme cases, sagging is allowed, but not more than 20 millimeters.

Sloping roof with a balcony, example in the video:

Installation of roofing materials

Using all possible space, giving the house originality and significantly reducing heat loss through the roof - these are the tasks that the attic solves. If there is a certain margin of safety at the foundation, in this way you can turn cottage in two-level. Another attractive thing is that you can build an attic roof with your own hands even without special construction skills. It is important not to make a mistake with the choice of materials and do everything according to the rules.

Windows on a regular floor are located in the walls. In attics there are no or almost no walls. They are replaced by a roof. That’s why windows are made special: they not only have to let light in sufficient quantity, but also withstand wind and snow loads, which are much greater on the roof than on the walls.

Dormer windows

When planning an attic, you should take into account the recommendations of SNiP. They recommend making the window area no less than 10% of the floor area. So if the attic is divided into several rooms, each should have a window.

Of all the methods shown in the photo for installing skylights with an attic, inclined installation is the easiest to implement. In this case, it is necessary to ensure the proper degree of waterproofing of the junction, and also to use special models with reinforced frames and reinforced glass - the load on the surface can be significant.

Advantages of a sloping roof window:

• more light, less sharp boundaries of light and shadow;
• the roof surface remains flat, its relief is not complicated;
• relatively easy installation.

When planning such a window, it is necessary to remember that its area increases with increasing angle of inclination. At what height is it more convenient to install such a window and how its height increases in centimeters depending on the inclination, look at the photo.

The steeper the slope relative to the floor, the smaller the window height should be.

The width of the window frame should be 4-6 cm less than the pitch between the rafters. Then it can be easily installed without disturbing the structure of the frame. If the window is wider, it is necessary to make a reinforced beam above it and calculate the load.

If you need to have a larger window, it is easier to place two narrow ones side by side. They look no worse than one big one, and there will be fewer problems.

When installing a dormer window, the roof geometry becomes more complicated: a valley appears on top and on the sides. Because of this, the rafter system becomes more complex both during planning and during assembly. The complexity of laying the roof covering also increases. All valleys are the places where leaks are most likely to occur. Therefore, everything needs to be done very carefully. In regions with big amount It is advisable to install snow guards over such windows to prevent them from being blown away in the event of a sudden meltdown.

Installation of a vertical dormer window in an attic roof

The advantage of such a window is that you can stand next to it at full height. But they let in less light, the terrain becomes more complex and the roof becomes more problematic.

A recessed window is usually used if there is access to a balcony through it. In other cases, this method of arrangement is not the best option: little light gets in, the shadows turn out to be very deep, which is tiring for the eye, the geometry also becomes more complex, although not to the same extent as in the previous version.

The easiest way is to make a window at the end of the attic. In this case, a reinforced frame or reinforced glass is not needed. Just high-quality glass is quite enough. It is this option that can most often be seen in country attics: this is the most inexpensive option that can easily be implemented with your own hands.

Rafter system

When independently building private houses with an attic, they usually choose a broken roof. It allows you to get a room of significant area, larger than under a gable.

With the same width of the base (of the house), the attic space under a sloping roof is larger than under a regular gable roof. The rafter system is becoming more complex, but a gable roof with an attic under a sloping roof is still more popular

The design of the sloping mansard roof is such that the overhangs can be lowered quite low, giving the house an interesting look. But the long overhang of the roof serves not only a decorative role. They also cover the upper part of the wall from precipitation and divert the bulk of the water away from the foundation. Although when planning you need to keep in mind that in strong winds they increase windage. Because of this, it is necessary to use more powerful boards and beams. Therefore, the size of the roof overhang is chosen based on several considerations, the main one of which is weather conditions.

Tilt angle

Depends on the roofing material, but most of all - on the region and weather conditions. The classic version is shown in the figure: the lower slopes in relation to the plane of the attic floor are inclined by 60°, the upper slopes by 30°. Based on these data and the parameters of your building, you can calculate all lengths. Just take into account that according to SNiP, the ceiling height in the attic cannot be less than 2 m. Then, by definition, this is an attic. A person will feel comfortable if the ceiling is raised to a height of at least 2.2-2.3 m. Based on this, according to the rules of geometry, calculate the required lengths.

In the classic version, the load from precipitation on the side surfaces may not be taken into account. Precipitation can only be retained on the upper part, the angle of inclination of which is less than 45°.

In general, the inclination of the side surfaces usually varies between 45° and up to 80°. The steeper the slope, the greater the windage it has, this must be taken into account: in regions with strong winds it is better to make flatter roofs. Then wind loads will be perceived much better.

Types of rafter systems for sloping roofs

The design of a sloping mansard roof is one of the options for the rafter system (the most common)

To make the frame of a sloping roof with your own hands, pine lumber is most often used, grade no lower than 2. The choice of cross-section of timber and boards depends on the size of the roof, the selected roofing covering (its weight), wind and snow loads in the region, and the pitch of rafter installation. All these parameters are taken into account in the calculation. The methodology is prescribed in SNiP 2.08.01-89 and TKP 45-5.05-146-2009.

One of the options for constructing a frame with hanging rafters

The figure above shows a drawing of a frame with hanging rafters. It can only be implemented if the base of the upper triangle is no more than 4.5 meters (in this case, this is the width of the attic room). If more, you will have to make layered rafters, which should rest on load-bearing wall in the middle (the attic will be divided into two parts by a row of beams).

Another version of the upper part is shown in the photo below (the picture is clickable). In this case, the side rafters are reinforced with struts. They significantly increase the rigidity of the system.

There is a second way to achieve a similar effect - to establish contractions - in the figure they are only outlined with barely visible lines. The length of the side rafter leg is divided by three, and contractions are established in these places. They will be needed if the roof covering will have a significant weight.

Option for installing a sloping roof truss system - with struts that increase the rigidity of the system

For a building that is small in size, the roof frame can be generally simple: at the top there are two hanging rafters, a tie rod, floor beams, racks and side rafters (pictured below).

Construction of a rafter system for a broken mansard roof for a small house

How to calculate a sloping roof

The attic sloping roof of a small house (no more than 6-7 meters wide) has been built so many times that, based on experience, we can say what materials should be used. Many parameters are dependent on other materials. For example, the installation step of the rafters is tied to the parameters of the insulation. To ensure that there is as little waste as possible during insulation and installation is simpler, it is necessary that the distance from one rack to another be slightly less than the width of the insulation (20-30 mm). So, if you are going to use mineral wool, its width is 60 cm. Then the racks need to be installed so that the gap between two adjacent ones is 57-58 cm and no more.

The width of the board for the rafter leg is again determined based on the insulation. For the central zone of Russia, the required thickness of basalt wool is 200-250 mm. That's not all. In order for the thermal insulation to dry, a ventilation gap of 20-30 mm is required (without it, condensation will gradually rot the wood and render the mineral wool unusable). In total, it turns out that the minimum width of the rafter leg should be 230 mm. The thickness of the board is at least 50 mm. This is in regions with light winds and not very heavy snowfalls. To summarize, for all rafters - ridge and side - a board of 230 * 50 mm is required.

If lumber with such characteristics turns out to be too expensive, it will be possible to do the insulation in two directions: partly along the rafters, partly, filling the sheathing, across. You can lay a minimum of 100 mm of basalt wool, therefore you can take a standard board 50*150 mm and leave a 50 mm ventilation gap, or order a non-standard 130*50 mm. It's up to you to see which is more profitable for the money.

For racks and beams, it is better to take a beam of at least 80 * 80 mm, better - 100 * 100 mm. Especially in areas with difficult weather conditions - heavy snowfalls or strong winds.

Order a more accurate calculation from specialists. This is a long process consisting of collecting loads from the roofing material, the structural elements themselves, wind and snow loads. After which, according to a certain formula, elements are selected. For more detailed information on how the calculation is carried out, see the following video.

Do-it-yourself mansard roof: installation procedure

The design of the Mauerlat on mansard roofs is no different from the standard version. If or logs, you can use the upper crown as a mauerlat. It is only pre-treated with impregnation with high protective properties.

If the wall is made of foam blocks, a reinforced monolithic belt is placed on top of it. On brick wall or made of shell rock or other similar materials, the construction of such a belt is not necessary. Waterproofing is laid in two layers on the wall, and on top is a timber treated with an antiseptic - 150 * 150 mm or a log. It is secured with embedded studs.

When assembling all elements, long nails are used - at least 150 mm long. In the most critical places, it is better to connect three or more elements using bolts or studs with double-sided threads. It is advisable to strengthen all joints with steel plates or corners.

First way

Installation of attic roof rafters is done in two ways. First: they assemble the parts on the ground, then in finished form lift up. There, the outer structures, which will become pediments, are put up first. They are placed vertically and secured. It is often more convenient to secure them with long bars nailed to the wall (temporary). The following assembled structures are inserted into the prepared recesses in the Mauerlat (they are made at the required pitch). They are positioned strictly vertically and carefully secured. If necessary, additional temporary spacers are installed to fix them in the desired position. Side beams are installed.

How to build a sloping roof in this way and assemble the nodes, see the video below.

Second way

The second method - the construction of a sloping roof is carried out sequentially by assembling elements directly on site. This method is more convenient if the structure is large and when assembled it can only be lifted using special equipment(faucet).

First, the floor beams are laid. Stands and ties are attached to them, and temporary spacers are installed to hold them in the vertical direction. Next, the upper and side rafter legs are assembled, and the tie rods and jibs are installed.

During installation, the following sequence of actions is observed: first, the outermost elements are installed and adjusted to the desired position, and securely fastened. If necessary, use temporary spacers. A fishing line, rope, and cord are stretched between them, which will serve as a guide for the installation of all subsequent elements. This simple move allows you to get the ideal geometry (don’t forget to check the slope angle, verticality or horizontality).

On top of the racks, tie-downs are attached - bars, to which the side rafters are then fixed and onto which the tie-down of the upper triangle is installed. The ties are secured using metal corners. Since the beams are long, they sag. This is later eliminated - after installing the upper rafter legs - with the help of vertical beams of fixed or adjustable height. And temporarily they can be supported with racks (so as not to pull the entire system).

To make it easier to maintain the desired angle when installing the side rafter legs, templates are made according to which cuts are made. But since the geometry of buildings built with your own hands is rarely ideal, adjustments may be necessary. To check the resulting angle of inclination, another template is knocked down from several boards, which is used to check the correct installation.

If the standard length of lumber - 6 meters - is not enough, either order the required length (expensive) or increase it. When building up, two boards measuring at least 0.6 meters (30 cm on each side of the joint) are nailed to the joint. They are nailed on both sides or bolts are used.

A reliable way to build rafters. The length of the “patch” is at least 60 cm

After installing the side rafters, all that remains is to install the top ones. A template is also made for them, pre-cut on the ground, and installed on top.

The top part can be made in different ways. Its structure depends on the width of the base. How to make it, look at the photo below.

Since the structure of the attic sloping roof does not provide for the presence of a ridge, a beam is placed in the middle to tighten it, to which the slopes are attached, fixing the triangle in the required position.

Nodes and their drawings

When installing a rafter system, questions may arise regarding the assembly of nodes—the intersections and connections of several structural elements. In the photo you see drawings of key connections.

The second option for connecting the side layered rafters and the upper triangle. Bolts are used for more secure fastening.

How to make a do-it-yourself fastening of the upper tee and rafter leg on an attic roof

Methods for attaching rafter legs to the mauerlat or, as in this case, to the side beam are shown in the figure below. To make it easier to mount a heavy element, a thrust board (bar) is nailed to the bottom of the rafter, which limits its movement: the board rests against the edge and does not allow it to sink lower.