Construction of a mansard roof do it yourself

The upper rafters of the attic roof can be an L-shaped structure. Truss legs between themselves can be joined end-to-end with the use of wooden or metal fixing lining, or by cutting in half-wood, 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 trusses are installed in the standard order – first extreme, then the rest with constant leveling.

At the last stage of the creation of a roofing structure, the installation of the batten, the installation of waterproofing, the creation of a ventilation clearance, and the installation of a roofing covering are done by hand. On the inside, heat insulation and vapor barrier are fixed, and sheathing is mounted. In the video you can get acquainted with the technology works.

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Construction of a mansard roof do it yourself

Use all possible area, give the house originality and significantly reduce heat loss through the roof – these are the tasks that the attic solves. With a certain margin of safety at the foundation in this way, it is possible to turn a one-story house into a two-level one. It also attracts that the mansard roof was built with its own hands can be even without any special construction skills. It is important not to make a mistake with the choice of materials and do everything according to the rules.

The windows in the usual floor are located in the walls. In the attic walls there are few or no. They are replaced by a roof. Therefore, the windows are made special: they not only have to transmit light in sufficient quantities, but also to withstand wind and snow loads, which are much larger on the roof than on the walls.


When planning a penthouse should take into account the recommendations of the SNiP. They recommend the area of ​​windows to do at least 10% of the floor area. So if the attic will be divided into several rooms in each there should be a window.

  Construction of a mansard roof do it yourself

Construction of skylights in the roof

Of all the ways in the photo of the device windows in the roof with a mansard, the most simple is implemented inclined installation. At the same time, it is necessary to ensure the proper degree of waterproofing of the junction, as well as to use special models with a reinforced frame and reinforced glass – the load on the surface is considerable.

Pluses skylight window:

  • more light, not so sharp borders of light and shade;
  • the surface of the roof remains flat, its relief is not complicated;
  • relatively easy installation.

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

The steeper the slope relative to the floor, the less should be the height of the window

The width of the window frame should be 4-6 cm less than the step between the rafters. Then it can be easily installed without disrupting the structure of the frame. If the window is wider, you need to do a reinforced beam above it, calculate the load.

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

Two windows side by side look no worse than one wide

When installing a dormer window, the geometry of the roof becomes more complicated: endova appears at the top and sides. Because of this, the truss system becomes more complex in both planning and assembly. Also increases the complexity of laying roofing. All endovy – the place of the most likely occurrence of leaks. Because here it is necessary to do everything very carefully. In regions with a large amount of snow, it is advisable to install snow guards over such windows: so that during a sharp descent they are not demolished.

The device of the vertical window-dormer in the roof roof

Plus this window: near it you can stand in full growth. But they let less light in, the relief becomes more difficult and the roof becomes more problematic.

A recessed window is usually used if they make an exit to the balcony through it. In other cases, this method of device is not the best option: there is little light, shadows are very deep, which is tiring for the eye, geometry also becomes more complicated, although not to the same extent as in the previous version.

The easiest way is to make a window in the end part of the attic. In this case, do not need a reinforced frame or reinforced glass. It is quite enough just high-quality glass. It is this option that can most often be seen in the country penthouses: this is the most inexpensive option that is easily realized by hand.

Rafter system

In the case of self-construction of private houses with a mansard, a broken roof is usually chosen. It allows you to get a room of a large area, larger than under the gable.

With an equal width of the base (house), the mansard room under the broken roof is obtained more than under the usual gable. The rafter system becomes more complicated, but a gable roof with an attic under a sloping roof is still more popular

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

Tilt angle

It depends on the roofing material, but most of all – on the region and weather conditions. The classic version is shown in the figure: the lower slopes with respect to the attic floor plane are inclined by 60 °, the upper ones – by 30 °. Based on this data and the parameters of your building, you can calculate all the lengths. Only it is worth considering that according to the SNiP, the ceiling height in the attic can not be less than 2 m. Then, by definition, this is the attic. Comfortably, the person will feel himself if the ceiling is raised to a height of at least 2.2-2.3 m. Based on this, according to the rules of geometry, calculate the required lengths.

Classic tilt angles

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

In general, the slope of the side surfaces usually ranges between 45 ° and up to 80 °. The steeper the slope, the more sail it possesses, it must be taken into account: in regions with strong winds it is better to do more flat roofs. Then the wind loads will be perceived much better.

Types of roof systems of broken roofs

Construction of a broken roof roof – one of the variants of the truss system (the most common)

For the manufacture of a broken roof frame, they often use lumber from pine, the grade is at least 2. The choice of cross-section of timber and boards depends on the size of the roof, selected roofing (its weight), wind and snow load in the region, and the rafter installation step. All these parameters are taken into account in the calculation. The technique is prescribed in SNiP 2.08.01-89 and TCP 45-5.05-146-2009.

One of the options for building a frame with hanging rafters

Above in the figure will lead a drawing of a frame with hanging rafters. It can only be implemented if the base of the upper triangle is no more than 4.5 meters (in this case, it is the width of the attic room). If more, it is necessary to do slant rafters that should rest on the supporting wall in the middle (the attic will be divided into two parts by a series of beams).

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

There is a second way to achieve a similar effect – to set up contractions – in the figure they are only outlined by barely visible lines. The length of the side truss legs is divided into three, in these places set contractions. They will be needed if the roofing will have a substantial weight.

The option of the device truss system broken roof – with struts that increase the rigidity of the system

For a small building in razorov, the frame of the roof can be generally simple: at the top there are two hanging rafter legs, a puff, floor beams, pillars and side rafters (in the photo below).

Construction of a truss system of a broken attic roof for a small house

How to calculate a broken roof

The mansard broken roof of a small house (no more than 6-7 meters wide) was built so many times that, based on experience, one can say which materials should be used. Many parameters are dependent on other materials. For example, the installation step rafters tied with insulation parameters. In order to keep as little waste as possible during insulation, installation was easier, it is necessary that the distance from one rack to the other be slightly less than the width of the insulation (20-30 mm). So, if you are going to use mineral wool, its width is 60 cm. Then the racks must be installed so that the gap between the two adjacent ones is 57-58 cm and not more.

The width of the board for the truss foot is again determined on the basis of insulation. For the middle zone of Russia, the required thickness of basalt wool is 200-250 mm. That’s not all. In order for the insulation to dry out, a ventilation gap of 20-30 mm is needed (without it, condensate will gradually rot out the wood and make mineral wool unusable). Total it turns out that at a minimum the width of the truss leg should be 230 mm. Board thickness – not less than 50 mm. This is in regions with gentle winds and not very heavy snowfalls. Summing up, for all rafters – ridge and side – required board 230 * 50 mm.

If lumber with such characteristics turns out to be too expensive, it will be possible to make insulation in two directions: a part along the rafters, a part, having filled the crate, across. It is possible to lay a minimum of 100 mm of basalt cotton wool, therefore you can take a standard board of 50 * 150 mm and leave for a ventilation gap of 50 mm, or order a non-standard 130 * 50 mm. This is a look that is more profitable for the money.

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

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

Mansard roof do it yourself: installation procedure

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

If the wall is made of foam blocks, a reinforced monolithic belt is arranged on top of it. On a brick wall or made of shell rock, other similar materials, the device of such a belt is optional. On the wall is placed in two layers of waterproofing, and on top – antiseptic-treated timber – 150 * 150 mm or log. It is secured with embedded studs.

How to attach the power plate and truss legs to it

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

First way

Installation rafters mansard roof do in two ways. The first: collect parts on the ground, then in finished form raise upward. There, the first to expose the extreme structures that will become gables. They are set vertically, fastened. It is often more convenient to fix them with long bars nailed to the wall (temporary). The following assembled structures are inserted into the prepared indentations in the mauerlat (they are made with the required pitch). They are set vertically, carefully fixed. If necessary, install additional temporary struts that lock them in the desired position. Side beams are installed.

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

Second way

The second method – the construction of a broken roof are consistently collecting elements right on the spot. This method is more convenient if the construction is large and when assembled, it can only be lifted using special equipment (crane).

First laid floor beams. They are attached to the rack and tightening, put temporary struts, holding them in the vertical direction. Next, the truss upper and side legs are assembled, and the braces and braces are installed.

During installation, the following sequence of actions is observed: first, the extreme elements are first set and set in the desired position, securely fastened. If necessary, use temporary struts. Between them the fishing line, rope, string, which will serve as a guideline for the installation of all subsequent elements, are being pulled. This simple move allows you to get the perfect geometry (do not forget to check the angle of inclination, verticality or horizontal).

On top of the racks fasteners fix – bars, to which the side rafters are then fixed and on which the tightening of the upper triangle is installed. Tightening fasten with metal corners. Since the beams are long, they sag. This is further eliminated – after the installation of the upper truss legs – with the help of vertical beams of a fixed or adjustable height. And temporarily they can be propped up with racks (so as not to drag the whole system).

One of the stages of building a mansard roof do it yourself

To make it easier to withstand the desired angle when installing the side truss legs, make templates, which make zapily. But since the geometry of self-made buildings is rarely perfect, an adjustment may be needed. To check the resulting angle of inclination from several boards, one more pattern is knocked down, which is used to verify the installation is correct.

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

Reliable way to build rafters. The length of the “patch” – at least 60 cm

After installing the side rafters remains to install the top. For them, too, a template is made, pre-washed on the ground, and installed at the top.

Almost finished frame

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

How can you make an upper triangle on a sloping roof

Since the device of the mansard broken roof does not provide for the presence of a ridge, a bar is fastened in the middle to which the braces are fastened, which fix the triangle in the required position.

The upper part is fixed by hacks, nailed to the bar laid in the middle

Ha it can be considered that the mansard roof is assembled with his own hands. It remains to mount the roofing material and do the warming (you can in this order, at the same time). Features of insulation roofs are described here.

Nodes and their drawings

When installing the truss system, there may be questions about the assembly of nodes – the places of intersection and connection of several structural elements. In the photo you see the drawings of key connections.

How to make the connection elements truss system broken roof

The second version of the connection side of the rafters and the upper triangle. For more reliable fastening bolts are used.

How to make the mount of the upper triangle and rafter foot on the roof attic with his own hands

Methods of attaching truss legs to the mauerlat or, as in this case, to the side beam are shown in the figure below. To make it easier to mount a heavy element, a thrust board (bar) is nailed to the rafter below, which restricts its movement: the board rests against the edge and prevents it from dropping below.

Several options for attaching rafters to the mauerlat

Construction of a mansard roof do it yourself

In an effort to effectively use the entire available area of ​​a country house, many owners equip the attic. While doing this, it is necessary to be prepared for the arrangement of the roof in a certain way. At its core, the attic is a converted attic and requires certain design solutions and some alterations in thermal insulation and roofing. In general, the construction of a mansard roof of a country house is not much different from the construction of roofs of another type. But due to the operational features of the roof of the attic and the requirements placed on it, it is necessary to have knowledge and understanding of the specifics of the arrangement of this type of roofs.

Types of mansard roofs

Like any construction work, the construction of the roof of the attic begins with the design stage and the selection of the most suitable for the construction of the mansard roof, its type and type. For the attic use single or regular and broken dual slope roofs. Everything else, the appearance of the roof is influenced by the materials used and the design features of the roof itself.

Depending on the structural design of the building itself, the construction of the attic uses several standard roof solutions. Attic roofs: photo and description

  • Duplex roof for a single-level attic. This option is a conventional duo-pitch roof, under which the attic is settling. During design and construction, there is no great difficulty due to simplicity of calculations and ease of work on the construction of the truss structure. The main disadvantage of this roof design is the small interior of the attic with rather low ceilings.
  • Broken gable roof for a single-level attic. Unlike the usual gable roof for the attic, the sloping structure uses 4 pitched planes located at different angles. This type of roof construction is somewhat more complicated in design and construction, but its undeniable advantage is the full-size interior.
  • Single-level mansard roof with external consoles. The design of this type of roof is more complex than the previous ones. But the spacious room and high-grade vertical windows compensate for the shortcomings in the complexity of design and construction. The design feature of the attic with such a roof is its displacement and extension beyond one of the sides of the house, and the roof looks more like a shed.
  • Two-level mansard roof with a mixed type of support. Roofs of this type are the most difficult in design and construction. Such roofs are designed in conjunction with the house, as one unit, due to the different levels of accommodation.

Mansard roof device

Different designs of mansard roofs in their design is not much different from conventional pitched roofs. Of course, there are certain design features, but in general they are the same as gable or single-slope, and consist of the following main elements:

Roofing. The outer part of the roof, which performs the function of protection against various atmospheric phenomena.

Crate. Most often wooden boards to which the roof is fixed, as well as insulating materials.

Ridge run. The top of the whole truss.

Rafters. These are the stiffening ribs of the entire roof construction; they can be nylon and trailing. Winged rafters are used for the roof of the attic.

Mauerlat. This structural element is a beam, laid on the perimeter of the external walls and connected with the walls with the help of special fasteners. The entire truss structure is attached to the mauerlat.

Diagonal connections. In order to ensure the reliability and durability of the entire truss structure, the rafters are connected with longitudinal beams and vertical stands with the help of diagonal braces or bevels.

Internal supports. To give the roof stability of the rafter and / or ridge girder propped up by vertical beams.

Insulation layer. Due to the fact that the roof of the attic and the interior premises are practically one whole, a multi-layer insulating cake is placed between the roof and the walls of the room to maintain the temperature and humidity conditions. The insulation consists of hydro and vapor insulation, sound and noise insulation, as well as a thick layer of thermal insulation. In addition, proper insulation of the roof of the attic is also important for the safety of the roof itself.

Mansard roof technology

In the design and construction of the roof roof, many builders and designers, either unknowingly or by doing their work somehow, make serious mistakes in insulation, ventilation and truss construction. The result is a mansard roof, which literally in a couple of seasons comes into disrepair, a fungus appears, mold, and the roof starts to leak or is completely destroyed. This happens because of a violation of the construction technology of the attic roof.

Due to the fact that the roof of the attic is maximally attracted to the walls of the interior, and it is quite difficult to obtain excellent heat transfer rates in this case, the entire construction of the roof should have excellent thermal insulation, ventilation and properly constructed truss construction using fire and biotechnological protection.

To attic roof turned out reliable and durable, you need to know the following:

  • thickness of rafters should be more than 250 mm. For such rafters, you can use glued laminated timber;
  • as insulation use materials that will not lose their properties in case of increasing humidity. For example, extruded polystyrene foam or foamed glass;
  • between the roof and the thermal insulation layer, we make full ventilation with air lines and hoods, through which air will circulate under the entire roof surface;
  • on the inside, the entire insulation surface must be equipped with a vapor barrier;
  • on the outside of the rafters, a layer of waterproofing and, if necessary, a layer of sound insulation are laid under the roof.

Such requirements are due to certain natural and physical phenomena. But first things first:

The greater thickness of the rafters is required for the possibility of laying a 20 cm thick insulation layer between them, and this in turn entails an increase in the mass of the entire roof structure, which the rafters hold on themselves.

Wood for the whole structure is treated with special means for protection against fire and microorganisms, which is a strict requirement of SNiP. This will save it from damage by fungi and increase its service life.

If such popular materials as mineral and glass wool are used for thermal insulation, then one can gain only in the convenience of installation and in alleviation of the whole structure. But cotton wool, whatever it is, is cotton wool, which, like a sponge, absorbs water, compresses and loses its insulating qualities. If you choose any material other than polystyrene and foamed glass, you should focus on full moisture resistance, low heat transfer coefficient and relatively low weight.

Thermal insulation thickness of 20 cm is necessary because it is very cold in our latitudes in winter, it is very hot in summer. A feature of the design of the attic are large heat loss in winter and the rapid warming of the room in summer. A large layer of insulation will prevent the loss of heat and its penetration inside. But this is only one of the reasons, the second is the safety of the roof. The fact is that the heat that leaves their premises in the winter warms the roof, on which lies a layer of snow and partially causes it to melt, and the snow is a natural heater. Melted snow at minus temperatures turns into ice, which has no thermal insulation properties, it makes the roof heavier and finally destroys the roof itself. And since in one day up to 100 cycles of thawing and freezing can take place, the roofing material will fail in just one season. In the summer, the room becomes incredibly hot and stuffy, and requires the installation of air conditioning, and even two. But these inconveniences can be avoided by equipping a thick layer of proper thermal insulation.

Equally important is a full roof ventilation. It will help cool the roof, both in summer and in winter, as well as remove excess moisture from under the roof. All this will ensure comfortable living in the attic room, protect against mold, fungi and decay, and in addition keep the roof from destruction in winter.

Regarding steam, water and sound insulation, then everything is simple. Vapor barrier passes through the excess moisture from the premises and prevents its penetration from the outside, waterproofing protects the insulation materials and the room from accidental moisture. A soundproofing reduces the noise level from the impacts of rain, hail and wind on the surface of the roof.

Phased construction of mansard roof

Performing all the work on creating a roof for an attic requires builders to have some experience in this area. Unlike conventional pitched roofs, building a mansard roof with your own hands is somewhat more difficult due to the arrangement of angled windows and a broken construction of slopes in the roof itself. To complete the construction of a mansard roof with your own hands, you must adhere to the following stages of work:


The first thing to do is develop a roof project. To do this, you can contact the experts or, if you have a good command of the computer, do everything yourself in the architectural program. Also at this stage, all the necessary calculations of loads, the angle of inclination of the roof slopes and so on. To do everything right, one should apply for the necessary information to such a document as the Loads and Effects SNiP.

Raising the truss frame

This stage of work is the most time-consuming, and in order for the mansard roof to be made qualitatively with its own hands, it will take combined efforts of 3 to 4 people. We begin the construction of the roof of the attic with laying and fixing the mauerlates along the entire perimeter of the house using a beam with a section of 100×100 mm.

Construction of the roof roof photo:

After that, we install a frame for placing the attic, the racks of which will also serve as supports for the truss structure. To do this, we use a timber with a cross-section not less than the cross-section of the longitudinal beams on which the stands will rest. First of all, we install vertical racks at the beginning and at the end of the building. We fix them to the longitudinal beams with the help of special stamped metal corners and self-tapping screws. To facilitate all work on the fastener use a screwdriver. Now we place the jumper on top of the racks and fix it.

We stretch the cord between the two arches, and if everything was done correctly, it will be strictly on the horizon, if not, you will have to disassemble one of the arches, trim a little and reinstall it. Now, on a stretched cord, we install similar arches with a step that is provided for rafters. The resulting arches are interconnected by bridges, which are fastened with stamped corners or nail plates.

Having collected the frame of the future interior, proceed to the installation of rafters. We start with those that have the greatest angle of inclination and are on the same level with the frame of the attic room. There are no special difficulties here. The rafter beam is trimmed to the desired estimated length, a groove is cut in the base of the beam for installation on the mauerlat, and the top is cut at a certain angle. After that, each rafter is set in place and fixed to the main structure.

The next step is somewhat more complicated, since you will have to install the upper rafters. The difficulty lies in observing a certain angle and centering of the whole structure. To facilitate the task, you can first make a template of two long boards that will exactly repeat future connected rafters. Using this template, trim the rafters on the ground and then put them in place. The installation algorithm rafters is the same as for the arches of the interior of the frame.

In completion of the installation of the truss structure we nail the crate. For crates can be used as ordinary boards, and sheets of plywood or chipboard. This will depend on the type of roofing materials.

Making an insulating cake

Having installed the rafters and crate, proceed to the creation of an insulating layer. To do this, first of all, from the inside of the rafters we put the vapor barrier and fix it to the rafters with brackets. Next, we lay the insulation material and carefully monitor that it lies close to the rafters and leaves no gaps. Over heat insulation, with a step of 50 cm, we fill the crate, which will keep all the insulation on itself.

On the outer side of the rafters lay a layer of waterproofing, which will protect against accidental penetration of moisture. In conclusion, over the waterproofing lay the roof.

Construction of the roof roof: video lesson

A variety of ready-made projects of the roof of the attic is very extensive. They can be with windows and without, rounded shape or strictly straight, with one slope or several. But whatever the roof of the attic, its construction will require the knowledge and skills of the master of construction.

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Sources:,, stroitelstvo-domov / stroitelstvo-mansardnoi-kryshi-svoimi-rukami

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