How is the roof under the attic. We make a beautiful attic floor with our own hands. Determination of the total weight of the roof

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. Most rational decision, allowing 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;
Crossbar - transverse horizontal elements, pulling 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 to be laid on top of them roofing and transferring the load to the truss 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 different shape 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 the frame of the interior 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 proceeding with the purchase of materials and the construction of the roof, it is necessary to draw a 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. AT wooden buildings the top 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. Align the Mauerlat along the inner plane of the wall, the wall remaining outside is later laid 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 of the required diameter is drilled through them. You can also mark the beam with a tape measure, but the probability of error in this case is higher. Laid on the wall roll waterproofing, you can use the usual 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 processed coated waterproofing and wrapped with ruberoid. 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 upper part 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 is performed rafter legs. 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

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

"Breaking" the roof slopes under different angles, you can increase the amount of space under the mansard roof. broken structure like the other kind mansard roof, more massive and heavier than a standard gable roof, which should be taken into account when equipping the attic floor in the process of reconstructing a house. 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 of a massive attic structure is planned at the stage of preparation for construction with your own hands, this should be taken into account when developing the 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 elements 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, which are used to calculate optimal angle roof slope and other parameters. 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 knives carpentry.

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 apply wooden dowels. The Mauerlat device requires high-quality waterproofing of a wooden beam. For this purpose, roofing felt or other durable materials with water-repellent properties can be used.

Mauerlat installation is necessary if it is planned to build a roof frame with your own hands, the rafters of which rest against the upper part of the wall 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 construction 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. You can learn about the main methods of connecting the elements of the truss structure 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 at a very sharp 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.

The device of the mansard roof allows you to significantly increase the usable area and rationally organize the space of a low-rise building. However, its construction often frightens home craftsmen with an overly complicated and time-consuming process.

You should not be afraid, because the result will provide beautiful roof and comfortable additional rooms. And in order for the result of the work to please the owner and household, you need to know according to what rules the roof truss system of the attic roof is built, in what way it is easier and better to arrange it.

At the mention of mansard roofs, we instantly recall the pentagonal gable construction of impressive size over a log house, concrete or brick walls. Visual memory suggests that its slopes must certainly have a slope of different sizes, i.e. Bottom part roofs simply have to be much steeper than the top. Due to the difference in the angles of inclination, a convex fracture is formed, which gave the roof the popular name "broken". The term reasonably migrated to the technical definitions of attic structures. It reflects the essence of the usual standard in the device, but often has nothing to do with the configuration. Despite the fact that the design of all mansard roofs necessarily includes two parts, visually their presence cannot always be determined.

Purely by external indicators, the predominant number of attic structures can be divided into:

Triangular roofs, the lower and upper parts of which have an equivalent slope. Outwardly, they resemble traditional gable structures without kinks in the plane of the slopes.
Pentagonal roofs with slopes having convex corners. This category clearly shows the presence of two docked parts in the design.

In both of these varieties, the truss system consists of two tiers stacked on top of each other. The lower structure forms usable space residential attic with a height of 2 to 2.5 m, so that it was not difficult to move inside it. The second tier creates the shape of the top of the roof, it is allowed to be of arbitrary height.

By varying the angle of inclination of the upper and lower rafter legs, you can get the roof shape that is optimal in your own opinion. It is believed that a pentagonal attic looks best, the corners of which are in contact with an imaginary circle.

Note that the principle of building a broken roof is suitable not only for gable truss systems. By interpreting the basic method, the attic can be arranged in hip, shed, tent and other roof structures.

Sometimes an existing structure is remodeled into an attic, in the construction of which “broken” technology was not used. However, these roofs a priori cannot be attributed to the attic category. True, no one bothers, with sufficient power of the rafter legs, to use the crossbars of pitched truss systems as ceiling beams, and supports of additional runs as a beam for sheathing the attic.

Found out that main feature mansard roof is the presence of two adjacent truss structures connected in a triangle or pentagon of a nice shape to the owner. In their construction, typical ones are used:

Layered, according to which the lower tier of the attic is built and used in the device of the upper part.
Hanging. In accordance with it, only the upper part of the structure is built.

If, for simplicity, the section of the mansard roof is divided into two halves, a trapezoid will be obtained below, and a triangle at the top. The inclined sides of the trapezoid are allowed to be exclusively layered, and the sides of the triangle are layered and hanging.

Basic schemes of truss systems

The "classic of the genre" is rightfully considered the pentagonal scheme of the mansard roof truss system with props that form the walls of the interior. Its section is conditionally divided into the simplest geometric figures. In the center is a rectangle, on the sides of which there are two mirror-image right-angled triangles, on top is an equilateral triangle.

Standard attic design

The rafters of the lower part of the structure rest on the Mauerlat below, and with the upper heel on the right or left run. Part of the frame of the mansard roof, crowning the structure, is made by hanging truss arches. They are supplemented with a hanging headstock in the middle if they are intended to cover a span of more than 3m. The headstock cannot be connected to the arch tightening with a notch, like a support post. Her job is to prevent sagging of the puff - this is not a support, but a suspension.

Supports-racks of the layered rafters of the lower part are supported through the bed on the ceiling. If necessary, to increase the stability under the props, struts are mounted. The racks are connected to the bed and girders with cuts, the junctions are duplicated by metal corners and toothed plates. If the ceiling is concrete, bituminous waterproofing is laid under the bed. The bed can be laid not on the floor, but on brick posts or leveling boards. When arranging an attic hardwood floor you can generally do without the bed and embed the racks directly into the beams.

The rather steep lower parts of the mansard roof slopes are practically not affected by the snow load, because precipitation does not linger on them. However, steeply installed rafters have another problem - gusty winds will tend to turn over and tear off the roof. Therefore, fastening the system to the Mauerlat must be taken very seriously. In the attic situation, each rafter is tied to the walls with twists, and not through one, as in conventional pitched structures.

The way to take out the rafters for the wall line

It often happens that the planned attic construction forms too narrow an interior space. It can be expanded by extending the rafter legs outside the walls. Those. the rafter leg will rest not on the Mauerlat, but on the beams of the upper floor. This case, in theory, does not need a Mauerlat at all. But reinforcing struts in the scheme with the removal of rafters are used without question, because there is no support at all under the extreme part of the side triangles.

The Mauerlat installation can be abolished, but the casting of a monolithic reinforced concrete belt for attaching beams to brick walls highly desirable. Floor beams to monolithic belt fastened with anchors, support posts are cut into them by a maximum of 1/3 of the thickness of the timber. Important point: the removal of the rafters from the wall is simply obliged to form a cornice for wooden houses at least 0.5 m wide, for concrete and stone at least 0.4 m.

Technology for the construction of a truss structure with the removal of the rafter leg beyond the wall:

We install the extreme floor beams that define the contour of the cornice overhangs. Because the ceiling will be loaded, the cross section of the beams is taken from 150 × 200 mm. If, when laying the starting beam, it turns out that the walls do not form a perfect rectangle, we strive to correct the flaws by changing the position of the beams.
On the laces stretched between the fixed extreme beams, we lay and fix the remaining bars. We control the height and step of laying the beams before fastening. The distance between the floor elements is equal to the step between the rafter legs. For insulated roofs optimal step installation of rafters 0.6m, because it is equal to the width. If the rafters are mounted with a similar frequency, they can be made from a 50x150mm board.
From the left and right edges, set aside a distance equal to the length of the short leg right triangle. At the marked points, carefully select the nests with a chisel to a third of the height of the beam under the extreme supports.
Let's make supports by cutting out spikes. They need to be made according to the size of the selected nests. For the manufacture of corner supports, a bar with a section of 100 × 150 mm is suitable, and two bearing supports for the gable sides of the roof should be made from it. Under ordinary racks, a beam of 50 × 100 mm is sufficient. The material for the support elements should be longer than the design height by the length of the tenon, but better by 10 cm in case of errors when stacking.
We install the corner posts and fasten them with temporary struts. We connect the racks with a cord.
Using a cord with a plumb line, we align in the beams the points for sampling nests for ordinary supports and select the indicated holes.
We install ordinary racks and two bearing supports in the centers of the attic gables.
We lay runs on the installed supports - boards with a section of 50 × 150 mm. We fasten the runs with corners. It is not necessary to use as many nails as in the corners of the holes. Enough two or three for each plane. As a result of laying the board, the frame of the walls of the future attic is obtained.
We connect the supports installed against each other with bars, attaching them to the girders with corners. These elements will act as tensile crossbars. Therefore, for their manufacture, lumber of the 1st grade with a section of 100 × 150 mm is required. Under each installed crossbar, a temporary support from an inch 25 × 150mm is needed.
From above, we temporarily fasten the crossbars with the same inch, stepping back from the edges of the frame 20-30cm. A temporary rare flooring of one, two or three boards is needed for ease of installation of the upper part of the truss system.
We make a template for the rafters of the lower row from an inch. To do this, we apply a blank board to the end of the run and the beam. Then we outline the lines of the grooves along which we have to cut off the excess. We try on, if necessary, trim the excess.
We make rafter legs according to the template. If there is any doubt about the impeccability of the construction, then it is better to cut only the upper groove for a start. By placing the rafter in its proper place, it will then be possible to adjust the lower groove after the fact without unwanted damage to the material.
We install the end rafter legs, which will need to be connected again with a cord.
Focusing on the lace, we mount the rafter legs of the lower tier of the attic.
Similarly, we make a template for the upper part of the truss system. In order to find the line of the upper cut, we temporarily sew a board onto the gable support.
We make a mirror counterpart for the previous template. The rafters of the upper tier will lean against each other.
Trying both templates on the roof. If everything is in order, we make the required number of upper rafters from a 50 × 150mm board using them.
We are constructing the upper tier of the truss system.
In order for the crossbars not to sag, we mount headstocks of the required size to each upper truss. We firmly sew them only to the ridge zone, the bottom should not be rigidly fixed.

Further, the rafter legs are screwed to the walls with wire bundles. Then the pediment frame is installed, along which it needs to be sheathed. At the end, the crate is mounted with a step corresponding to the characteristics of the roofing material.

Skeleton method

The technology differs from the previous method in that not separate supports are installed on the ceiling, but modules-blocks of the side walls of the future attic are fully prepared for fastening.

The block method of arranging the truss system allows you to optimize the construction of the mansard roof, because the construction of modular elements is carried out on the ground. In calm conditions without a sense of height, it is easier to achieve the accuracy of nodal connections.

The process of installing a block mansard roof:

According to a pre-made project, we manufacture frames for the walls of the attic. Longitudinal bars according to this method play the role of runs and beds. We lay them out together with the racks on a flat area and mark with the help of a square the nests for the supports of the side walls. We make cuts along the measured lines.
We cut spikes on the racks, the size of which must correspond to the size of the nests.
We connect the longitudinal beam with vertical posts, we get two modular frames - these are the walls of the attic.
We raise the frames up, install them in the intended place. We temporarily fix the position of the walls with spacers, then attach them to the floor beams with brackets.
With a chisel, we select nests on the edges of the beams for installing the lower row of rafters. You need to place them in one line. In order to observe the geometry, it is easier to first outline them with a chainsaw, then refine them with a chisel.
We carry out the upper truss tier of the attic on the ground, having previously tried on blanks for the installed elements. For accuracy of fitting to the end of the future roof, we temporarily nail the board so that one of its edges clearly repeats the central axis of the truss system. The base of the upper attic triangle performs the function of stretching. Its length is equal to the distance between the outer vertical planes of the installed frames. We select nests along the edges of the stretch, and spikes on the lower heels of the rafters.
Collecting roof trusses of the upper tier, for reliability we mount an additional crossbar, we strengthen the ridge knot with a triangular wooden lining.
Until we moved to the roof, we make blanks for rafter legs. We try them on the frames laid out on the ground. It is more convenient to “cut” them in one fell swoop, grabbing a few pieces with a clamp. We cut out only the upper bevel, taking into account the fact that it will rest partly on the wall rack, partly on the stretching of the upper truss trusses.
We try on the lower rafter to the end. We draw in the area of her lower heel the shape of a spike, repeating the configuration of the nest in the beam. We cut out the spikes.
We move to the roof of the farm of the upper tier and the rafter legs of the lower tier. We mount the farms first, attaching them to top harness walls with brackets, then the rafters of the lower part, attaching them to the floor beams with all the same brackets.

The subsequent stages of roof construction are carried out according to standard rules. The drawings for the mansard roof, which clearly represent the structure, will be introduced in detail to the described principles of the construction of the truss system. Thanks to the production of connections by cutting in half a tree, the strength and rigidity of the frame as a whole increases, which will allow not to mount additional struts.

The disadvantage of the method is that ready-made modules quite difficult to transport to the roof. To transfer the assembled blocks there without the use of lifting equipment, a minimum of 4 people will be required.

Plank and nail truss system

Build a powerful attic over small country houses impractical, but you still want to save space in a small area. For the owners of small buildings, there is an excellent option - a light board-and-nail layered structure. The method should appeal to adherents of economy, because the whole timber is not used in the construction.

For the manufacture of each of the supporting elements, two boards are used, between which spaced pieces of the bar are installed. The bar-shaped cavity explains why the system is lightweight compared to solid counterparts. To ensure spatial rigidity, wind contractions are installed that connect the supports to the rafter legs. The crate, in turn, will contribute to the strengthening of the structure.

People's way of designing a layout

For a successful result of the work, the project is very desirable. It is not a fact that the presented drawings with dimensions are suitable for arranging a particular house. Typology in construction is now not at all welcome. If there is no documentation at all, it is better to make at least a sketch of the future roof, not forgetting the height of the ceilings in the attic room. Wherein:

Proportions should be observed, because too large an attic can turn small house into an awkward, mushroom-like building.
It must be remembered that the lower part of the mansard roof is built using layered rafter legs, and they optically underestimate the overhang and block the upper part of the high windows. There will be no tangible effect of overhanging when constructing an attic according to the scheme with the removal of rafters.
Do not forget that the height of the attic room must ensure freedom of movement. It is this landmark that is required to correctly determine the height of the racks of the attic walls.

You can choose the best proportions of the roof in a folk template-layout way. According to it, bars or boards are laid out on a flat, spacious area, repeating the contour of the building in real size. By changing the angles, moving the components, you can achieve the optimal configuration. Elements need to be fixed with nails and immediately measure the lengths of beams, rafters, puffs, racks. The resulting dimensions will help in the manufacture of templates.

Calculations and planning of the truss system under the mansard roof will be demonstrated by the video:

The basic options and diagrams of the attic truss structure given by us will help determine the choice of the optimal type of truss structure.

The cost of building a roof is 25-35% of the cost of building the entire house, and the cost of work is 50-80% of the price of materials, so if you build a mansard roof with your own hands, then the savings can be 15% of the total estimate.

Mansard refers to any roof under which there are rooms suitable for habitation in height (mansard, or attic floor).

The device of a mansard roof is a complex and painstaking work.

In industrial construction, the installation of the roof is carried out when the drawings display each node, the fastenings of the parts and the parts themselves with the dimensions taken out.

Builders do not think about the roof device, about whether the load is calculated correctly, their task is to build a frame by sawing out templates of parts and fastening them together, while the system for fixing the roof elements is also indicated.

To figure out how to make a mansard roof, you will have to study the video, photo and master the theoretical part.

Comfortable ceiling height for living quarters from 2.5 m and above. The walls of the attic floor are most often roof slopes, so it is necessary to ensure their thermal insulation.

The top of the mansard roof is a ridge, a beam that lies parallel to the floor plane of the house, and is the most high point roofs. The ribs of the roof are called rafters.

Ridge (upper) rafters descend from the ridge. beams attic floor connect the bases of the left and right ridge rafters of the same roof section.

Racks (bars with a section of 100x100) are fixed on interfloor overlap at a right angle at a distance of 0.8-1.5 meters from the outer wall.

The higher the racks and the closer they are placed to the walls of the house, the larger the attic living space will be.

The side (lower) rafters go from the attachment point of the attic beam to the Mauerlat. Each section of the mansard roof consists of two ridge rafters and two side rafters on each side.

The system of the rafters of the same name forms a slope - ridge or side.

The most used version of the mansard roof is a broken one. gable roof. In this case, the ridge and side rafters form an obtuse angle at the connection points.

If they lie on the same straight line, then outwardly it looks like a classic gable roof.

When calculating the slope of the slope, the materials of the future roof and climatic conditions are taken into account, it can range from 15 to 45 degrees. The greater the slope, the less snow will linger.

In regions with little snow, the sloping roof of a house can be quite flat.

The standard slope of the slopes is 30-35 degrees.

Preparatory work

Roof attic type planned even before laying the floor between the first and attic floors.

If you will use wooden beams, then it is necessary to provide for the cross section of the beam and the distance between the beams so that they can withstand the permissible load for a residential second floor.

Usually these are beams with a cross section of 150 cm and above with a length of 6 m. Such beams are located at a distance of 80-90 cm from each other.

The system is such that the longer the beam, the more load it will experience in the middle. The pressure will be created by the floor of the attic floor itself, the furniture and, in fact, the residents.

Even if the attic is planned for unfurnished lounges, floor beams with a cross section of less than 120 cm, laid at a distance of 100 cm from each other, are undesirable.

A reliable device will provide the right materials for the mansard roof.

The heavier the roofing materials will be, and the longer the frame of the sloping roof, the larger the cross section is needed for the timber from which the frame can be built.

Usually, sections 60x120, 60x100 cm are used.

In many photos, there is no reinforcing belt device along the external load-bearing walls when a sloping roof is planned.

The weight distribution system is such that the entire weight of the roof rests on the floor beams, and they, in turn, transfer this and their weight to the walls.

gable roof one-story building much lighter than a broken attic, so a mauerlat (wooden sheathing along the perimeter of the walls below the floor beams) is quite enough.

If the walls are made of timber or brick, then the Mauerlat will make sure that the mansard roof device is reliable. It is important at the stage of building walls to provide a device for fixing the Mauerlat.

The system must be reliable. In the case when a hollow cinder block or porous foam concrete is used as a material for the walls, it is difficult to secure the Mauerlat to the wall.

A good solution would be a reinforcing concrete belt, in which, at the level of pouring, rods are placed to install the Mauerlat.

It is placed on a substrate of roofing material or other insulating material and aligned with the inner edge of the wall.

Before fixing, make sure that the bars forming the Mauerlat lie strictly parallel. Even a deviation of 2-3 cm will cause the slope to sag.

If the house is up to 6 meters wide (maximum allowable size unsupported interfloor beam), then the floor beam rests on the Mauerlat with both edges.

If the width of the house is more than 6 meters and the house has load-bearing walls perpendicular to the floor beams, then the floors are installed according to the following system: one edge of the beam is attached to the Mauerlat, and the second to the internal load-bearing wall, on which the Mauerlat is already installed.

In continuation of this line, the next beam from inner wall to the opposite outer Mauerlat. The gap between the beams should be at least 3-4 cm.

If the preliminary work is done correctly, then you have received a completely finished floor between the first and attic floors. Now it's time to draw the future frame.

Start studying the theory with a photo of a sloping roof and with a video that shows the installation of a mansard roof.

Draw the house from the front side, the racks on the left and right, bring out the rafters and calculate the angles of inclination. Increase or decrease the height of the posts to change the slope of the slope.

Calculate the length of the rafters (the cosine of the angle of inclination multiplied by the distance from the rack to the projection of the ridge - for the ridge slope, and the cosine of the angle of inclination of the side slope, multiplied by the distance from the Mauerlat to the rack - for the side rafters).

Watch the video various options fastening the bars to each other. High-quality fastening will provide a reliable frame.

If climatic conditions overload the high sloping roof with winds, and the width of the house does not allow much space for unused space behind the racks, then you can reduce the height of the racks and, after construction is completed, install built-in wardrobes around the entire perimeter of the side walls of the attic.

Frame assembly procedure

Make the roof frame only from high-quality wood. The main sign of a "stale" tree is a dark color.

If you can not buy dried in drying chamber wood, then get raw, but still at the stage of building walls.

Fresh wood cannot be used for the frame - under the influence of loads, it will lose its shape and bend.

Raw timber can be dried naturally one and a half to two months.

To do this, we lay it out clearly in level with a distance between the bars of up to 5 cm. No two bars should touch. Every 75-100 cm, the beam should rest on a flat surface.

As support points, you can use a cinder block laid out on a flat area, but in no case can you use another beam intended for the frame.

In sunny and warm weather, the bars dry naturally, and in rainy weather they need to be covered. The manufacture of the frame is allowed only from completely dried wood.

Start the installation by making sure that the racks and rafters are straight wooden bars and there are no cracks or knots.

Saw-cut wooden blanks of the same type must be treated with a fire-fighting agent and a mixture that prevents the formation of fungus.

Processing should be done twice with an interval of 1-2 days. Installation can begin when the tree has dried after the treatments.

The procedure for assembling the frame step by step:

Rack installation. On top of the floor beams, we put 5-6 boards, 5 cm thick, without fixing. They form a floor on which you can safely move. Beams of the same size are installed on the floors according to the level. First put extreme. Be sure to make sure that the opposite distances between the racks are equal. Then a cord is stretched between the extreme bars. It performs the function of the level at which all others are set. A harness is placed on top of the racks and fixed. Now we have a rectangle in which all other supports are mounted. To reduce the precariousness of the design of the rack, it is necessary to unfasten it with jibs to the floor beams. It is the racks - the most weakness in the frame system, so we will pay special attention to their fixation. The rack with the floor beam must be fixed with construction bracket size 12-14. When all the racks are installed, wedge them with an overlap using a beam with a section of 50-60 cm. It is worth additionally fastening them on the outside with each other using an unedged board;
Installation of upper slopes ( gable roof). At the top, the rafters are fastened together with brackets. The ridge rafter rests on the strapping of the racks and is fixed to the beam of the attic floor. The installation of the upper triangle of the attic must be carried out only on the ground and the fully finished structure should be raised. The triangle is laid on the racks and attached to them with brackets. As soon as the installation of the second triangle is completed, it is necessary to connect them in several places to each other. When all the structures are exposed, you can fix them with a crate;
At the top of each side rafter, a groove 3-4 cm deep is cut out, and the racks are tied into it. Groove angle equal to the angle slope slope. A groove is also made at the bottom of the side rafter for installing it on the Mauerlat. Due to these two grooves, the unloaded rafter can stand without fixation. Before applying the load that the crate will carry, you need to fix the side rafter with a bracket to the strapping and to the Mauerlat. Additional fixation should be carried out with self-tapping screws, twisted at the attachment points of the rafters, at an angle;
Lathing - edged or unedged board or OSB plate- fixed to the rafters with self-tapping screws. The edges of the slopes should be even. The distance between the components of the crate depends on the roof. For slate, a distance of 3-4 cm is allowed, and for shingles a solid crate is required;
It remains to build the gables and insulate the slopes and the broken mansard roof is ready.

Take photos and videos as you go through each step. This will help to understand the errors in case the result obtained does not satisfy you.

To work you will need tools:

hammers of different sizes;
screwdriver;
a circular saw;
pliers and small carpentry tools.

You will also need consumables:

staples size 12 or 14;
wood screws 45-50 cm long for battens and 150 cm long for additional fixation of rafters;
hydrobarrier;
construction stapler;
as insurance - the installer's belt.

It is better to call 2-3 assistants for help (it is really possible to cut the cut yourself on the ground, but the installation of structures at a height cannot be done alone).

An attic in a private house is an ideal solution for expanding a residential or useful utility area without completing the top floor. The arrangement of the attic in the attic space is an original and new exterior of the house, saving energy by reducing heat losses in the roof, and increasing living space. But the large size of the house is not a reason to start work on arranging the attic: you need to have a foundation with a sufficient margin of safety for the weight load, since the finished attic space will have to be thoroughly redone.

Features of the attic

The main difference between the attic and ordinary premises- it has almost no walls in the usual sense, since the walls are a modified truss system, constructed from many inclined roofing surfaces. Therefore, the design of the window will be very different - it should not interfere with natural light, and should take on the load in the form of precipitation and strong wind - the impact weather conditions on a sloping roof is stronger than on massive building elements.

Important! The SNiP regulation stipulates that the area of the window opening should not be less than 10% of the floor surface in the common room. Therefore, when separating attic space partitions, it is desirable to make a window in each newly formed room.

It is easier, cheaper and faster to mount an inclined window in the attic roof than to make a special vertical ledge under it, violating the design calculations. In any case, the window opening must be waterproofed or a window with reinforced glass and a reinforced metal-plastic profile should be ordered.

Benefits of installing an inclined roof window:

A large stream of natural light, smoothing chiaroscuro;
There is no need to radically alter the shape of the roof and change its relief;
Simple installation, feasible for the owner himself.

The degree of illumination depends on the area of the opening, which is proportional to the angle of the roof. Therefore, the conclusion is obvious: the steeper the broken mansard roof, the wider and higher the window opening should be. The thickness of the metal-plastic profile should almost fit into the distance between the rafters, so that there is something to attach the window to without destroying the rafter system. If you order a wider window, you will have to make a reinforced jumper that fastens the rafters cut at the insertion point. If necessary, installation wide window you must first think about the option of installing two small adjacent windows so that the roof remains intact.

When installing a window-dormer (dormer) vertical window, requires the removal of the frame outside the attic) geometric shapes roofs need to be complicated by the installation of the upper and side valleys, and the laying or installation of roofing is also complicated. Ready system rafters are much more difficult to remake at the same time than laying in your individual new roof window. Valleys must be carefully waterproofed, as their location and geometry relative to constant atmospheric influences make these places the most vulnerable to the penetration of moisture and cold. In regions with an average annual high precipitation, it is recommended to make snow retainers above the dormers. But the main advantage of a dormer is that you can stand next to him in full height- outweighs all eliminated shortcomings.

A window recessed into the roof is made if an exit to the balcony is organized through this window. In other cases, this is an unattractive option: poor natural lighting, unjustified complication of the roof geometry, high labor costs with a minimum of effect.

Most affordable option- a window at the end of the attic - cheap and practical solution, which is fully realized without outside help.

Attic truss system

AT individual construction a house with an attic is often built with a sloping roof, although this is an expensive solution. Broken mansard roofs, due to their design features, greatly increase the usable area interior spaces attic. With the same width of the foundation of the house and the floor, the rooms in such an attic will have a larger area due to ledges and niches than rooms under the roof conventional design.

Standard design a sloping roof allows you to lower the overhangs of the eaves much lower, not only making the exterior of the house very original - such overhangs protect the walls and foundation of the house from wind and moisture, directing atmospheric precipitation away from housing.

The more complex the sloping roof with your own hands, the stronger the dependence of the reliability of the structure on the materials from which the roof is made, on climatic conditions, on the thickness of the beams of the truss system and other factors. The classic do-it-yourself mansard roof, the drawings of which are given below, has a slope ratio of the lower slopes to the floor of 60 °, of the upper slopes - 30 °.

SNiP stipulates comfortable height ceilings in attic rooms- at least 2 m. Therefore, a scheme with a roof slope of 600 is fully justified, and the reliability of the structure is ensured by thicker floor beams and rafters than with a conventional gable roof.

In the classical construction of the attic, the force of the wind and the load from the weight of snow on the sides of the roof with a large slope are not taken into account. Snow will accumulate on the upper surface of the roof, made with a slope of 300-450. The greater the angle of inclination of the roof, the stronger the windage of the roof, therefore, in climatic conditions strong wind you need to build roofs with a small slope, and this is a problem for arranging an attic - the area of \u200b\u200bthe house in such conditions should be quite large.

Broken roof schemes

The sloping roof frame is constructed from pine lumber of the first or second grade. For calculations, such parameters as the cross-section of timber and batten boards, the dimensions and weight of the roof from various building materials, snow and wind loads, and the rafter attachment step are regulated.

The design of the roof with a hanging truss system is justified if at the base of the triangle (in the upper figure) there is a size ≤ 4.5 m - this determines the width of the attic. If the width is greater, then layered rafters are equipped, which are mounted on the wall.

How to calculate a broken type roof

The step between the rafters is often determined by the width of the insulation - this solution allows you to save on roll materials, and the distance between the rafters is chosen 2-3 cm less than the width of the insulation material. For example, with a slab width mineral wool at 60 cm, the distance between adjacent racks should be 57-58 cm.

The boards of the rafter legs are also calculated in width, based on the parameters of the insulation. To ventilate the layers of thermal insulation, it is necessary to provide a ventilation gap of 20-30 mm, otherwise the accumulated condensate will cause the wood to rot, and then damage the insulation. For the conditions of the middle strip, the thickness of the insulation can be no more than 230-250 mm, therefore the minimum width of the rafter legs is 230 mm with a board thickness of ≥ 50 mm. The greater the wind, temperature and snow loads in the region, the thicker the rafters should be made.

Recommended: To save lumber, the insulation can be laid in two directions: along and across the rafters, making a thin and rare crate between the layers. With a minimum thickness of basalt wool slab of 100 mm, a 50 x 150 mm board can be used, leaving ventilation gap 50 mm.

Mansard roof installation

Mauerlat on the mansard roof is equipped with standard techniques - fastening the beam to the wall with knitting wire, anchors or studs. If the house is timber or log, then the upper crown of the log house, impregnated with an antiseptic and substances that increase the moisture resistance of wood, can serve as a Mauerlat.

For a Mauerlat in a house made of cellular concrete, a monolithic reinforced grillage is poured on top of the walls, and the Mauerlat itself is attached to the rods concreted into the wall. For walls made of brick or reinforced concrete, such a concrete grillage is not necessary - the wall material itself is quite durable and will withstand any method of attaching the truss system. It will only be necessary to make a two-layer waterproofing around the entire perimeter of the house, and a Mauerlat beam with a section of 150 mm.

To assemble the elements of the rafter structure, use long nails- 150-200 mm. Corners and intersections bearing walls With internal partitions at home it is better to make bolted connections, or use double-sided threaded studs. Also, all intersections of roof elements are recommended to be additionally reinforced with metal plates-overlays.

Installation of the attic truss system can be carried out in two solutions:

Assembling the elements on the ground, lifting the finished structural units up. First of all, vertically corner elements are attached, which form future gables. The remaining elements of the roof structure are vertically inserted into the grooves made in the Mauerlat beam at a calculated distance and rigidly fixed. To give rigidity and correct geometry, you can temporarily fix the elements with spacers and braces, and after mounting the side beams, when the structure acquires the desired rigidity, the spacers can be removed;
The second method is the sequential assembly of the mansard roof in place. It is more efficient and more convenient to work this way, because with a voluminous rafter system it will be problematic to lift the assembled roof manually - you will have to rent a crane. After assembling the structure, floor beams are laid, to which vertical beam racks are attached to the grooves, and temporary braces are installed to stiffen and make the system vertical. Then comes the assembly of the upper and side rafter legs, the jibs and struts are mounted in the same way.