Do-it-yourself construction of a mansard roof. How the mansard roof truss system works: an overview of structures for low-rise buildings How to make a roof with an attic

A do-it-yourself mansard roof built over the house allows you to increase the total living area with minimal financial investment. Among the most popular options is a gable sloping roof, the installation technology of which is not difficult.

Project development

By “breaking” the roof slopes at different angles, you can increase the amount of space under the mansard roof. Broken structure, like another view mansard roof, more massive and heavier than a standard gable roof, which should be taken into account when equipping attic floor in the process of home renovation. It is first necessary to examine the condition of the foundation and walls of the structure to determine whether they can withstand increased loads. If the device is massive attic construction planned at the stage of preparation for construction with their own hands, this should be taken into account when developing a project for the foundation and walls of the house.

The creation of a mansard roof project should be taken carefully, since errors in calculations or incorrectly selected parameters of the elements of the truss system can lead to damage to the roof itself, and in some cases the walls of the house, during operation.

It is recommended to entrust the development of a mansard roof project to professionals. It is also possible to use special computer programs, with the help of which the calculation of the optimal angle of inclination of the roof and other parameters is performed. All calculations are performed in accordance with the document SNiP "Loads and Impacts".

When choosing an attic project, the construction of which can be done by hand, first of all, you need to pay attention to the dependence of the parameters of the room on the angle of the roof. The dwelling must have a height of more than 2.2 meters. If the roof slopes are straight, then the angle of their inclination seriously affects the width of the room.

A broken mansard roof allows you to maximize the expansion of the room, providing the required ceiling height across its entire width. At the same time, the side (lower) rafters are located at an angle of about 60 degrees, and the angle of inclination of the upper ones can be chosen at your discretion, based on aesthetic preferences, as well as snow and wind loads characteristic of the construction area.

Roofing cake and other elements

If you are going to make an attic roof with your own hands, it is necessary to provide for the use of certain materials for the installation of a roofing pie in the project. They include:

waterproofing;
vapor barrier;
insulation;
roofing material.

The choice of insulation affects such a parameter as the pitch of the rafters - in order to save thermal insulation material it is recommended to position the rafters in such a way that the slab or mat fits snugly between them. The type of lathing (solid or sparse) and the step of the sparse lathing depend on the choice of roofing. It should be noted that the device of the roof of the attic floor provides for the creation of not only high-quality insulation, but also effective ventilation of the roofing system.

Materials and tools

In order to ensure safety, the construction of the truss system and roofing should be carried out using fireproof, environmentally friendly materials. Wood materials are treated with fire and biological protection means.

For the construction of the truss system of a private house with your own hands, you will need:

wooden beam with a section of 50 × 100 mm;
board 150 × 50 mm;
unedged board;
nails 80, self-tapping screws and other fasteners;
annealed wire (diameter 3-4 mm);
level;
plumb;
roulettes;
hacksaws;
axes;
hammers;
sharp carpentry knives.

The use of quality tools simplifies and speeds up installation wooden structures with your own hands. Instructions for doing work step by step can be found in the video.

Mauerlat device

The Mauerlat, made of timber or a powerful board, acts as the base of the roof truss system of the mansard roof. A gable roof requires laying a Mauerlat on the long walls of the house. Mauerlat not only allows you to securely fix the lower part of the rafters, but also contributes to an even distribution of the load when it is transferred to the walls and foundation of the building.

To fix the Mauerlat board or beam, metal studs are used, fixed in a monolithic concrete beam made in the upper part of the wall, or annealed wire embedded in brickwork. When attaching the Mauerlat to the upper crown wooden wall wooden dowels are used. Mauerlat device requires high-quality waterproofing wooden beam. For this purpose, roofing felt or other durable materials with water-repellent properties can be used.

Installation of a Mauerlat is necessary if it is planned to build a roof frame with your own hands, the rafters of which rest against upper part walls with a beveled end or a special cutout. If an attic is designed, the width of which actually corresponds to the width of the house, the rafters rest with their lower end against the outriggers. Powerful beams laid across long walls act as supports. The number of supports should correspond to the number of truss pairs. The beams are attached to the walls in a similar way to the Mauerlat, and waterproofing is also used.

Mauerlat or support beams must be securely fastened to the walls, as these elements prevent the roof from moving under strong wind loads.

Construction of the supporting structure

The structure of the frame of a broken mansard roof begins with the laying of supports under the racks, which must be located strictly symmetrically relative to the axis of the building. The distance between the supports is equal to the width of the future attic. First of all, U-shaped arches are mounted on the gables of the structure. Each arch consists of two support posts connected by a bridge. For the manufacture of racks, a beam is used, the cross section of which must be no less than the cross section of the support under it.

Racks are installed on a plumb line, strictly vertically. A jumper is attached to them, the horizontalness of which should be checked during installation. According to the size of the first arch on the other front, the second is made. It is important to level the structure. A cord is stretched between the U-shaped arches, which must be located strictly horizontally. If necessary, one of the arches is dismantled and adjusted exactly to the size. Focusing on the stretched cord, you should install the remaining arches. Their number and pitch depend on the designed pitch of the rafters, since the upper end of each rafter is attached to the corresponding post. This provides the necessary rigidity of the mansard roof frame.

Racks of U-shaped arches can be attached to the support with metal brackets, nails or tenon joints. About the main ways of connecting elements roof structure You can find out from the video instructions. To ensure the verticality of the racks under the load that the roof will experience during operation, it is recommended to additionally install braces. The arches in the upper part are interconnected by lintels parallel to the long walls of the house.

Installation of rafter legs

DIY construction broken roof involves the use of two types of rafter legs. The lower rafters are located under very acute angle, connecting the racks with the Mauerlat or the ends of the extended transverse supports. The upper gable truss structure is mounted on an arched system.

Before installing the lower rafter legs, it is necessary to carefully mark the place of their installation on the Mauerlat. The rafters extreme to the pediment are mounted first. The trimming of the rafter legs is carried out in such a way that the cut of the upper edge of the board fits at the required angle to the rack, and the lower cut rests on the power plate or outrigger. If, according to the project, the mansard roof is made with slope overhangs, a special-shaped cutout is made in the lower part of the rafter leg: the rafter rests on the support with the horizontal part of the cutout. The rafter is fastened with nails or staples. It is additionally recommended to strengthen the connections of the legs with the Mauerlat or the remote support with burnt wire with a diameter of 3-4 mm. According to a similar scheme, all lower rafters are installed.

If we are building a house whose length exceeds 8 meters, it is recommended to install a truss system with a ridge beam. Such a device allows you to evenly distribute the load on the entire frame. In this case, racks are installed in the center of the gables, the verticality of which is checked by a plumb line, a ridge beam is mounted strictly horizontally on them. It is important to correctly determine the height of the ridge, since the angle of inclination of the upper rafters directly depends on this. The rafter legs rest with their upper cut ends against the ridge beam, and the lower ones against the supporting arched structure.

The upper rafters of the attic roof can be an L-shaped structure. The rafter legs can be butted together using a wooden or metal fastening plate, or by cutting into half a tree, using a bolted connection. It is recommended to fit the first pair of rafters in place, which is then dismantled and used as a template. Prepared farms are installed in the standard order - first the extreme ones, then the rest with constant leveling.

At the last stage of creating a roof structure, do-it-yourself installation of the lathing, laying waterproofing, creating a ventilation gap, and installing the roofing are carried out. From the inside, thermal insulation and vapor barrier are attached, the lining is attached. On the video you can get acquainted in detail with the technology of work.

Attic called the roof, under which the living rooms are equipped. The shape of the mansard roof can be different, but most often the attic is equipped under a gable roof. The most rational solution that allows you to get the maximum usable area of \u200b\u200ba residential attic is a mansard roof with a broken slope line.

The stages of building a mansard roof with your own hands are in many ways similar to the construction of a regular one, as well as the names of the elements that make up its frame. These include:

Mauerlat - a support beam that transfers the load from the rafters to the walls of the building;
Floor beams - boards that form the attic floor and the ceiling of the lower floor;
Racks - vertical supports supporting the truss system;
Runs - horizontal supports for rafters;
Rigel - transverse horizontal elements that pull the roof slopes together, otherwise they are called puffs;
Rafters - boards that form the main contour of the roof;
Suspension - a suspension rack that supports puffs and redistributes the load between the rafters;
Sheathing - boards or sheets of plywood designed for laying roofing over them and transferring the load to the rafter system;
Filly - boards fixed along the axis at the bottom of the rafters and designed to form a roof overhang.

The cross section of the roof elements is determined by calculation, the article presents the most commonly used materials in private construction.

The device of a broken mansard roof and its differences

As already mentioned, a roof with broken slopes is somewhat different from a simple gable roof. The difference lies in the shape of the opposite slopes: they are not a straight line, but consist of two slopes connected at an obtuse angle. The roof can be either symmetrical or have a different shape of opposite slopes - it depends on the project.

Thanks to the broken shape, the usable volume of the attic space is significantly increased. The lower part of the rafters is usually set at an angle of about 60 degrees to the horizontal, and the support posts supporting these rafters act as a frame. internal walls. The upper part of the rafters is most often installed at a slight angle, from 15 to 45 degrees - this allows you to save materials, but maintain the functionality of the roof and its resistance to snow loads.

Vertical racks resting on floor beams, purlins and puffs connecting them form a parallelepiped that limits the internal dimensions of the attic. To give the structure additional rigidity, struts are installed between the floor beams and the lower rafters. After installing the upper rafters, to strengthen the truss and eliminate the sagging of the crossbars, hanging supports - grandmas are installed. To further strengthen the lower rafters, they are pulled together with racks using contractions. The elements are fastened with nails and bolts or studs.

Calculation of the dimensions of the mansard roof

The main condition for a comfortable attic device is the height of the ceilings - it should not be lower than 2.5 meters. To ensure such a height of the room, the break line of the mansard roof must be at a height of at least 2.8 meters, taking into account the thickness of the insulation layer and the inner lining of the attic, as well as the thickness of the finishing floors.

Before you start buying materials and building a roof, you need to draw detailed drawing, which will indicate the overall dimensions of the house, the line of slopes and the height of the attic.

Drawing - mansard roof dimensions

The technology of erecting a broken mansard roof

Install the Mauerlat around the perimeter of the house. In wooden buildings, the upper beam or log serves as the Mauerlat. In stone - brick or block - structures, the Mauerlat beam is attached to studs or anchors fixed in the walls during masonry at a distance of no more than 2 meters. The Mauerlat is leveled along the inner plane of the wall, the wall remaining outside is later laid with decorative masonry. Mauerlat timber from dry softwood usually has a section of 100 or 150 mm. Saw off the beam of the desired length, straighten the anchor studs if necessary and lay the beam on top of them. Lightly tapping with a hammer. Dents from the studs remain on the beam, a hole is drilled through them required diameter. You can also mark the beam with a tape measure, but the probability of error in this case is higher. A rolled waterproofing is laid on the wall, you can use an ordinary roofing material in two layers. Mauerlat is put on the studs and the nuts are tightened.
For floor beams, coniferous timber with a section of 100x200 mm is usually used. Floor beams are placed either on top of the Mauerlat with an exit beyond the plane of the walls by 0.3-0.5 meters, or in specially designed pockets in the masonry. In the first case, the beams are fixed with corners and self-tapping screws. To make the floors even, the beams are laid in strict sequence: first, the extreme ones in level, then, pulling the cord, they align the intermediate ones along them. The step of the floor beams is usually from 50 to 100 cm, but the most convenient step is 60 cm, which allows you to lay the insulation boards without trimming. To equalize the height of the beams, they are hemmed or board linings are used. If the beams are placed in special pockets in the masonry, their ends must be treated with coating waterproofing and wrapped with roofing material. Align them in the same way.
Racks are installed on the extreme floor beams. The end posts are made of timber 100x150 mm, the height and installation line of the posts is determined according to a previously prepared drawing. Racks are leveled using a level and a plumb line and temporarily fixed with jibs in perpendicular directions - along and across the axis of the roof. This will allow you to install the racks without deviations in any direction. The jibs are made from any board and nailed. A cord is pulled between the extreme drains and the rest of the racks are set along it with a step equal to the step of the floor beams, that is, for each beam. All racks are fixed in the same way as the extreme ones. You should end up with two rows of uprights of the same height, running parallel to each other.
Runs from a board 50x150 mm are laid and fixed on racks, runs are fixed on nails 150 mm and on corners using self-tapping screws. Crossbars from a 50x200 mm board are placed on the runs with the narrow side down - this will increase their rigidity. Since there will be no load on the crossbar during operation, this section of the board is quite enough, however, in order to exclude their deflection and increase reliability during installation, when installing the crossbars, temporary supports from the board are placed under them no thinner than 25 mm. On top of the crossbar, they are fastened with one or two boards - also temporarily, before the installation of the rafters. At the same time, the boards should not be placed in the middle of the puff - there they will interfere with further installation, but retreating about 30 cm. After installing the racks, girders and crossbars, you get a rigid structure that limits the interior of the attic. To increase its strength, it is subsequently fixed with struts and contractions.
Installed from a board 50x150 mm. First, a template is made from a 25x150 mm board - it is easier and faster to process. A board of the required length is applied to the upper run, washed down the shape directly on the board and cut out. A template is applied to the run at the installation sites of the rafters, and if it matches everywhere, then the upper part of all rafters can be made according to the template. The lower part, which rests on the Mauerlat next to the floor beams, is cut out in place each time. The rafters are fixed with the help of corners and self-tapping screws and on nails.
To perform the upper rafters, it is necessary to mark the center of the roof. This can be done with a temporary stand nailed to the Mauerlat and an extreme tightening from the end of the roof so that one edge of the board runs along the center line of the roof. The rafters are aligned along this edge. Next, a template is prepared from a 25x150 mm board, applying it to the edge of the installed board at the desired level and to the run on which the lower rafters rest. Mark the top and bottom cuts and cut out the template. Apply it alternately to both sides of the roof, checking how accurately its center is marked. If the rows of racks are made in parallel, then there should be no problems with installing the upper rafters - they will all have the same size.
According to the template, the required number of rafter legs is performed. The rafters are installed on the girders and connected in the upper part with the help of overhead metal plates or board scraps for self-tapping screws. In the run, the rafters rest on the cuts and are fixed on the corners. In order for the rafters to stand straight, they are fixed with the help of struts installed with the lower end on puffs. So put all the rafters. Hanging racks are attached - pieces of board 25x150 mm. The upper edge of the board is fixed at the junction of the rafters, the lower edge - to the puff.
They put struts under the lower rafters from a 50x150 mm board, resting them with their lower oblique cut against the floor beam and fixing them on the corners, and the upper edge is attached to the side of the rafter leg, nailed to one or two nails, and then drilled through hole and fastened with a bolt or stud. After installing the lower struts, remove all temporary supports and racks.
Gables are sewn up, leaving door and window openings. If the floor beams are laid in the pockets of the walls, fillies are attached to the lower rafters - boards that continue the line of the rafters and form a roof overhang. When laying floors on top of the Mauerlat, the beams already protrude to the required distance, and there is no need for fillies.
corresponding to the type of roofing - solid or sparse. Waterproofing is placed on the crate and the roofing is installed, for example,.

A sloping mansard roof usually does not need insulation - only the walls and ceiling of the attic are insulated. The air space formed under the rafters ensures good ventilation of the attic, reduces the heating of the attic rooms in summer and provides additional thermal insulation in winter. Therefore, when sewing gables, it is important to leave ventilation windows in the upper part of the roof, above the floors of the attic floor.

Video - instructions for building a mansard roof

broken roof- this is essentially a kind of gable roof. Most often, people choose this design when they want to get more living space on the attic floor. And someone just visually likes this form more than the usual gable.

This article will describe the sequence of erecting a sloping roof when the rafters are supported on the floor beams. Further, I will often refer to previously published articles and. Therefore, I recommend that you first familiarize yourself with their content, if you have not already done so.

So, we start by taking a piece of paper (preferably in a box) and drawing on it the foot of our house with the obligatory observance of scale. Anyone who can draw on a computer is great. Now, based on our personal preferences, we draw (also on a scale) the future roof. At this stage, you need to decide on the height of the structure, with the angles of inclination of the slopes and with the location and size of the window openings.

As an approximate recommendation, I can give you a diagram with proportions that I usually use in my practice. In the figure, the height of the break location of 3.1 meters allows you to ultimately get the final height of the ceilings on the attic floor (with plasterboard trim on the frame) of at least 2.5 meters. The angles of inclination of the side slopes and the upper ones are approximately 60 ° and 30 °, respectively. By the way, the angle of inclination of 60 ° allows you to ignore the snow load when calculating the rafters of the side slopes. All these dimensions are optional and you can adjust them at your discretion.

Now we need to select the sections of the elements of the truss system and calculate them for strength. For this we use the program that we talked about in the article. We calculate the rafters of the side slopes in the tab “Sling. 1″ Having chosen a suitable section, you must also write out from the diagram the value of the vertical reaction force (red arrow up) at the top of the rafter. Let it be "Q1, kg".

We calculate the rafters of the upper slopes in the "Arch" tab. On the schematic, first of all, specifying the value of L, we substitute the value of h0 equal to h. Having selected the section of the rafters, we also write out the value of the vertical reaction force from the diagram, but already at the lowest point of the rafter. It will be designated "Q, kg".

Adding the values of Q1 and Q, we get the concentrated load N, which is transmitted through the racks to the floor beams. We use it when choosing the section of racks and floor beams.

Having decided on all the dimensions, we proceed to the direct construction of a sloping roof. As an example, let's again take a box of a house measuring 8x8 meters:

Step 1:

We install the Mauerlat and floor beams. The details of this process have already been described in the article, so I will not repeat myself. The cross section of the floor beams according to the calculation is 100x200 mm.

Step 2:

We expose the racks along two lines (strictly vertically), first the outer ones from the bar 100x150 mm, then pulling the laces - intermediate ones, with a section of 50x150. The distance between them is no more than 3 meters. We fix all racks with temporary struts. In order not to clutter up the drawing, I showed the spacers on only one rack. We take the height of the racks 10 cm more than the desired height of the finishing ceilings in the rooms.

Now I want to make one important remark. It often happens, especially when a new roof is being made on an old house, that by expanding the floor beams when looking at them from above, we will not get a strict rectangle. The house may be slightly narrowed in any direction. This is not scary, but to facilitate the work, you need to put the racks so that a rectangle is sure to turn out of them. This will allow us to make all the rafters of the upper slopes according to one template. Otherwise, the rafters will have to be placed along the cord and cut in place, and this takes a lot of time and effort.

Step 3:

We put runs from a 50x150 mm board on top of the racks and install the remaining missing racks also with a section of 50x150 mm. No more spacers are needed. The resulting structures will play the role of the frame of the future side walls of the attic room.

Step 4:

We install and fasten on the runs, for example, with the help of roofing corners, puffs (crossbars). Their cross section for this example (the length of the puffs is 5.5 meters), I calculated according to our program in the “Beam” tab in the “Distributed load” plate. At the same time, “Load (normal)” and “Load (calc.)” were taken equal to 150 kg/m². There is no operational load on them.

The calculation showed that with a section width of puffs of 50 mm, the section height should be at least 210 mm. But I still took boards with a section of 50x200 mm. We will eliminate the unacceptable deflection by installing hangers (see below). Of course, this will give an additional load on the rafters of the upper slopes, and therefore, we will increase the cross-sectional dimensions of the rafters of the upper slopes obtained during the calculation from 50x150 mm to 50x200 mm.

When installing puffs (crossbars), we put a temporary support under each of them approximately in the middle of the span. In this case, the resulting sagging can be reduced. It is enough to use an inch 25x150 (only one such support is shown in the figure). They are needed so that when installing the rafters of the upper slopes, calmly walk on puffs, without fear that they will break, and, as I said, to reduce sagging.

Having installed all the puffs, we fasten them on top with a board (25x150 mm). The structure will become more rigid. Do not place this board strictly in the middle. Step back from the axis in any direction by about 20 cm. Why, it will be clear later.

Step 5:

We install the side rafters (left figure). This is done in the same way as described in the article on the gable roof. We also prepare a template, make the upper washed down, mark the lower washed down in place and fasten the rafters.

We install plugs for insulation (right figure). By the way, when I wrote about the gable roof, I completely forgot about them.

Step 6:

We begin the installation of the rafters of the upper slopes.

To begin with, we make a rafter template. To do this, take a suitable piece of board 25x150 and temporarily fix it strictly vertically on the extreme crossbar according to the figure. One of the upper corners of this board (for example, like my right one) should coincide with the geometric center of the roof, i.e. the right side of the board coincides with the axis of the roof (dashed line in the figure). Now we take a suitable board (also an inch, to make it easier), apply it and draw the lower and upper cuts with a pencil.

We make two rafters according to the template and install them. Three people need to work. We do not use a ridge beam here. Having installed the first pair of rafters, we fix it with a brace so that it does not fall.

Next, we put all the other rafters. On a roof like ours (length 8 meters), it will be enough to install four struts, two in different directions. The remaining pairs of rafters, while there is no crate, are temporarily fastened with an inch board (see figure).

Step 7:

According to the picture we sew pendants (board 25x150). They will prevent the puffs (crossbars) from sagging when we remove the temporary props. Now we see why we didn’t put the board fastening all the puffs strictly in the middle. Otherwise, she would be in the way now.

Step 8:

We install the gable frame and sheathe it.

After that, we make cornices, lathing, gable overhangs and gable ebbs. How to do all this, read the article about the gable roof. Again, I will not paint everything over again.

I hope this article will be useful for someone.

In an effort to make the most efficient use of any available space in its country house owners sooner or later come to the arrangement of the attic. And many dream to cope with this on their own.

But do they know that a do-it-yourself mansard roof will actually be reliable and durable only if certain rules and requirements are followed during its construction. It would not be entirely correct to say that the construction of a mansard roof according to technology is very different from the construction of other roofs, however, there is still a certain difference. So what is the difference between a mansard roof device?

Varieties of mansard roofs

A do-it-yourself mansard roof is a great opportunity to expand the usable space in a private house. What will be the dimensions of the space enclosed between the gables of the building and the slopes of the roof depends on the shape and design of the roof.

Mansard roof: photo of a roof with broken slopes

The roof of the mansard type is of several types:

Shed. This is the simplest option, however, in practice it is rarely used, for the most part, to make attics in small country houses.

Mansard roof projects with two slopes

The following types of gable roofs are distinguished: gable and broken. Gable gable, perhaps, has no rivals in popularity yet. Neither its design nor its own construction, as a rule, does not cause any particular difficulties.

Gable roof attic

The scheme of the mansard roof with a symmetrical gable system is quite simple. The pediments of such houses, more often wooden, have a triangular shape. The supporting structure of the gabled mansard roof includes inclined or hanging rafters.

On a note: for buildings up to 6 m wide, the classic roof option with a slope of 45 degrees is considered optimal. For wider ones, pointed ones are suitable - with an angle of inclination of 60 degrees.

The design of the mansard roof gable

A broken mansard roof differs from a gable roof by the presence on each of the slopes of two sloped planes, gentle and steep. The slope of the upper one is about 20–30 degrees, the lower one is 60–80 degrees. This is an economical option for a private house, the width of which is not more than 6 m. Making a sloping mansard roof with your own hands is a little more difficult, but it pays off with a full attic floor area, which allows you to equip a bedroom, a nursery, a kitchen, etc. inside the mansard roof frame of this type consists of farms in which the rafters are reinforced with racks, and the lower belt becomes the basis of the attic floor. The fracture points are reinforced with stretch marks.

The design of the attic floor of a broken and plucked roof

Another type of gable is a half-hip. It can be designed as a whole as a conventional symmetrical truss structure based on a Mauerlat, with the only difference being that there are small slopes above its gables.

Four-pitched mansard roof

The design of the hipped roof allows you to equip an additional floor under it - spacious and comfortable. Installation of a mansard roof with four slopes is certainly more difficult than the manufacture of a gable system. Its truss system is considered the most complex. A special approach requires the placement of skylights. In a hip roof, they are usually installed in the plane of the roof pie. Beautiful provide effective lighting.

Important: There is, however, a certain drawback in such a solution. If the windows are not tightly closed during bad weather, the room will flood rainwater.

vertical skylights on a Danish hip roof

More practical in this sense is the Danish version. Unlike the classic hip, in their upper part there are gables that allow you to organize attic lighting using ordinary vertical windows.

Hip roof skeleton with attic

In a conventional hip roof, the rafters are straight, without fractures. The upper end of the corner ribs rests on a ridge, the length of which depends, in particular, on the planned truss system. Four-pitched roofs are also broken. The implementation of such a design is quite complicated, but it allows, in accordance with the plan, a significant increase in the usable space of the attic floor.

Tent attic - almost hip. Almost, because all its slopes, having the shape of an isosceles triangle, are mated at one point, that is, the hipped roof does not have a ridge.

domed roof

The variety of mansard roofs does not end there.

Multi-pinch, which is a combination of several gables, have a complex geometry with many kinks.
Conical, vaulted, domed with exquisite design, etc.

All these options are considered very difficult to perform and initially require a professional approach. This is a whole range of tasks, from drawing and calculation to coating material, for which you need to find the right solution. The unusual and special aesthetics of these roofs, as a rule, increases the number of pitched breaks that form many internal corners (valley). Each of them carries a potential danger to the integrity of the roof. In these areas, as a rule, rainwater is retained and snow bags are formed, which cause leaks.

Roofs of houses with an attic: photos of the main floor options

Calculating a mansard roof in this case is almost impossible without special skills, so if your dream is a do-it-yourself attic roof, then choose a project with less complex elements so as not to face the need for constant repairs.

How to calculate a mansard roof

The design of the mansard roof, compared to the usual one, is distinguished by the presence of many additional elements, for example, exits to the roof or skylights. Quite often, attic projects also include balconies or terraces. All this, of course, somewhat complicates the rafter system of the structure, along with its calculation.

A mansard roof is erected not only during the construction of a house, it can also be a reconstruction non-residential attic in a residential heated room, and then its size and area can be severely limited. All this is taken into account when choosing and calculating the truss system. In addition to the rafters, the carrier system, as a rule, includes racks, crossbars, struts, suspensions, and for each of them it is necessary to correctly calculate the section.

Mansard roof: attic frame drawings

Roof area calculation

The next step is to calculate the area of the roof itself. The simplest options are single and gable roofs. To calculate the area, elementary formulas from the school geometry course are used: the length and width of the slope are multiplied. For a single-slope, this will be the desired value, and for a dual-slope, the obtained values \u200b\u200bare added.

Let's take a more complex, broken surface as an example. To calculate the area, it is conditionally divided into separate elementary geometric figures, calculate the area of each of them and add the results.

The plan of the mansard roof will help to isolate the figures required for the calculation

How to calculate the slope of the roof without errors

How to build a mansard roof so that it is comfortable and warm, but at the same time safe, resistant to various influences, and within an estimate that matches your capabilities? When constructing an attic, it is necessary to take into account all the requirements as a whole, since they are, to one degree or another, interrelated. For example,

with a large angle of inclination, the load on the truss system is much reduced. This is on the one hand, and on the other hand, the useful area of the attic is reduced, and material costs increase significantly;
an excessively small slope increases the climatic loads experienced by the roof, so the calculation is carried out taking into account increased strength. At the same time, the weight of the structure increases, due to which the loads on the foundation increase significantly.

The relationship between the angle of inclination and the truss system

When calculating the angle of inclination, the following factors are taken into account:

climatic conditions, in particular, the level of precipitation in the area, maximum wind and snow loads;
architectural solution;
design features of the house and attic;
roofing material.

On a note: for a gable roof, a slope of 45 degrees is considered optimal, and for a broken one - 60 for the lower and 30 for the upper slopes, respectively. With such parameters, with a well-thought-out interior, you can get a room that is comfortable for living.

Formulas for calculating the angle of inclination of the hip roof

For an individual calculation of the slope, knowledge of the basics of geometry is sufficient. In the section from the side of the gables, the roof most often has a triangular shape. Having the height and base values, you can easily calculate the length of the side and the value of the angle adjacent to it. In the calculations, Bradis tables are used, which allow the angle itself to be found by the value of the tangent.

How to build a mansard roof

So, how to make a mansard roof so that the space under it becomes as convenient and useful as possible? We will not focus your attention on the description and calculation of the truss system, and we will begin a step-by-step description of the attic roof assembly with the installation of a Mauerlat.

Mauerlat is a bar with square section(100x100 or 150x150 mm), on which the entire roof structure. Moreover, it evenly distributes the load on the foundation and building construction. It must be carefully secured. For example, in brick houses a beam of monolithic concrete is poured into which mounting studs are mounted, on which a Mauerlat is mounted.

Mauerlat attached to the wall

To build broken roof for the attic, you first need to get a frame for the walls. This is a construction of vertically installed support posts with horizontal ligaments. Their height, taking into account the requirements for the attic room, should be at least 2 m. The rafter system will be assembled on the frame in the future, so the support posts are installed in accordance with the rafter pitch calculated before.

The construction of the frame of a broken mansard roof

The installation order is as follows:

along the fronts of the building, U-shaped racks are mounted;
a cord is pulled strictly horizontally between them, if necessary, the racks are adjusted in height;
with a guide to the cord, the rest of the arches are installed;
connect them with horizontal bridges.

Rafter installation

Installation of rafters begins with those with a maximum angle of inclination.

Installation of side rafters

A groove is cut at the base of the timber, and the upper part is cut at a certain angle. Then each rafter is fastened with a groove to the Mauerlat, and with the upper end of the main structure.

Fastening rafters to Mauerlat

The next step is the installation of the upper rafters. Here it is very important not to disturb the centering of the structure. To do this, you can make a template from long boards according to the optimal angle of inclination of these rafters.

Top rafter template

Then, according to the template, for convenience, first on the ground, L-shaped structures are made, they are raised to the roof and firmly fixed to the frame.

Important: for a heavy roof structure in long attics (more than 7 m), it is better to install a ridge beam through which the loads are evenly distributed.

Depending on the selected coating, a solid or sparse crate is stuffed onto the rafters.

Attic roofing cake

The technology for building a mansard-type roof, as you can see, is not very complicated, however, it will be useful to see how practically how a mansard roof is built with your own hands. Video materials also present how to properly perform fasteners.

At first glance, the functions of the roof are obvious - it is protection from precipitation, wind, cold. However, it is also an opportunity to increase the usable living space at the expense of the attic space. Even in your own home, square meters are never superfluous, so you should not recklessly neglect the opportunity to equip a full room or an extra bedroom without endangering the family budget.

The mansard gable roof has been known for a very long time, at first the premises under it were used only for servants to live and store things. Of course, the living conditions that such a construction gave cannot be called comfortable - no heating, no windows, a low overhanging ceiling. However, architects began to look for ways to use this space rationally. And, admittedly, they were found, since now gable roof with an attic in terms of convenience, it is in no way inferior to other residential premises, especially, because with a reasonable approach, you can provide a standard ceiling height, windows normal size and comfortable temperature.

Advantages and disadvantages

Obtained by connecting two slopes, like any building solution, it has its pros and cons, which the house builder should be aware of in advance. The advantages include:

Its design does not require strengthening the foundation, which simplifies construction work and optimizes costs. The attic can be equipped even in a completely finished house, just rebuilding, insulating the roof.
Ease of installation. This design is easy to assemble, even a few craftsmen or a team of specialists of two people can handle it.
Rationality. Efficient use of space under the roof, which can be equipped as an office, winter Garden. Gable roof with unheated attic room suitable for seasonal storage.
Availability. All materials used are inexpensive and available for purchase.
Low cost. Square meter living space when installing a mansard roof with your own hands will cost you much less than building an extension or a full-fledged second floor.

Below are, if I may say so, the disadvantages of a gable roof with an attic, which would be better called its features:

To equip a spacious room with your own hands, you need a fairly high gable roof, the design of which is technically more complex.
An increase in the slope of the roof slopes increases the consumption of materials, and therefore the cost of construction, even if you do it yourself.
The design assumes the possibility of heat loss during the heating period.
Increased heating of the roof and under-roof space in hot weather.

Construction types

Though the design gable roof with an attic is considered traditional, it has many different designs:

Device of gable blood with an attic

The most important in the attic device - rafter system, which, like a skeleton, like a frame, bears the weight of the roof, gives it the necessary shape and serves as the basis for the floors. Therefore, it must be strong, able to withstand heavy loads. In order to have no doubts about its reliability, it is better to carry out an engineering calculation with your own hands or using a calculator to calculate the temporary and permanent loads to which it will be subjected. Each truss system consists of the following elements:

Mauerlat. Roof base that mounts flush at the top perimeter bearing walls. Usually, a beam is used as it, the cross section of which depends on the mass of the roof. They fasten it to metal studs or fittings, having previously waterproofed it with a roofing material.
Rafter. Boards measuring 50x150 mm or 100x150 mm, installed at an angle, with the upper part they converge into a ridge, and the lower part abuts against the Mauerlat. The rafter legs are the main supporting element of the system, they give the roof a triangular shape, forming its slope. The distance between them is laid in the range from 60 to 120 cm.
Skate. The upper corner of the triangle of a gable roof is formed at the meeting point of two rafter legs.
Crossbars, stretch marks. Horizontal reinforcing elements installed between the rafters in order to extinguish the bursting load. The higher this element is located, the thicker the timber is selected for it.
Racks, grandmothers. Vertical supports located under the center of the rafter or under the ridge, the roof rests on them. They transfer the load from the ridge to the load-bearing internal walls.
Strut. Rafter legs, corner supporting elements that divert the load from the rafters to the load-bearing partition.
Sill. In fact, the same Mauerlat, only located on top of the internal load-bearing floor, is also made from a square bar.
Fight. A horizontal bar that dampens the bursting load between the vertical supports of large roofs.
Crate. The base on which it is subsequently covered roofing. Most often, unedged boards or moisture-resistant plywood sheets are used for it. The gable roof is equipped with a solid or trellised crate, depending on the roofing material.

Installation steps

If you want to limit construction costs, best option for you - a gable roof with a residential attic. You can build it with your own hands in a couple of weeks, and a small professional team can do it in a matter of days. Construction should begin with the installation of the lower beams, which can be dispensed with only if there is wooden floor. The next step is the installation of racks, they are fastened with brackets or spikes and supported with temporary braces for greater stability, because they will become the "skeleton" of the attic. Next, the installation of the Mauerlat begins, on which the rafter legs are attached. As rafters, you can use only straight boards, without knots.

First of all, the rafter legs are adjusted at the gables, and then along the entire length of the walls in increments of 60-120 cm, depending on the width of the insulation and the weight of the roofing material. The final part of the work should be the installation of waterproofing, vapor barrier, battens, counter battens. If a gable roof with an attic will be used as housing, it must be insulated with basalt-based mineral wool, ecowool or foam. At the end, gables and overhangs are sheathed with any lumber, and the roof surface is covered with metal tiles, ondulin or euroslate. So, having spent a minimum of funds, you can increase the living space of your house by one and a half times with your own hands, making it comfortable and attractive!