Roofing pie for different types of roofs: installation, assignment of layers and laying. Mansard roof device: design features Mansard roof pie

Most of the complaints, already with the finished attic, you can hear that in the overbuilt room it is not warm enough, humid, there is a bad smell. It seems that everything was foreseen, insulated, waterproofing and vapor barrier were laid, but they did not get the desired result.

The first mistake made may be not observing all the subtleties when carrying out insulation work. For example, the absence of thermal insulation pads when mounting rafter legs from boards.

There are also mistakes in the arrangement of the “pie” of the roof itself. The roof of the attic differs from the usual roof in that it experiences a double effect of heat flows: heat and moisture enter the roof from the lower floor, and from above the roof subject to external temperature changes and atmospheric precipitation. And not always, especially in winter, these temperatures coincide. Hence the condensation, and moisture, and evaporation.

If the thickness of the insulation is not calculated according to special tables and formulas, this is the next construction error. Installation "by eye" leads to unnecessary loss of temperature in winter. It should be noted that the choice of insulation is of great importance. If you have a choice, take a roll insulation or tiled, give preference to tiled. insulation does not roll in slabs, does not deform and does not move out.

Do not forget about ventilation, vapor barrier and. It is not allowed to use a waterproofing or vapor barrier film with tears, deformations. Even a small hole received during transportation or installation itself will lead to unnecessary consequences. Each section of the roof must be thoroughly ventilated. This is difficult to do if the mansard roof has many windows and various openings for ventilation of the room, chimneys.

There are cases when waterproofing material, for the purpose of economy or out of ignorance, do not overlap. Then atmospheric moisture will definitely get on the insulation, hence the bad smell, and rotting rafters. A lot of new waterproofing films appear on the modern market. When installing, you need to carefully read the instructions for using such a film. It is especially worth paying attention to membranes that need to be laid with a certain face up. Violating this method of laying, you get defective waterproofing.

Another scheme roofing cake

For good ventilation, it is recommended to use "superdiffusion" waterproofing films. Then ventilation will occur only under the outer layer of the roofing material and the film due to the space formed by the crate or counter-crate.

The next mistake in the arrangement of the roofing "pie" may be the incomplete fit of the vapor barrier film to the insulation. Available in view of the presence of holes near the windows, chimney, etc. Through them, warm air from the lower rooms will penetrate to the insulation, condensation will fall, which will cause heat loss and rotting of the wood. It is recommended to glue the vapor barrier at the joints, to the walls, around any openings.

Failure to comply with all requirements leads to a reduction in the life of the attic roof.

Today in the section "Drawings and Diagrams" Evgeny Zvyagintsev, our friend from Novosibirsk, presents his version of the attic. His drawing of a roofing cake is due to the use of soft tiles - one of the most used roofing materials today.

Below is a drawing of a roofing cake (projection from the gable):

So, consider the presented drawing. Roofing cake from top (from the street) down (to the room).

The first layer is roofing shingles. As you know, a flexible tile is a roofing material, on the fiberglass base of which a layer is applied bituminous mastic sprinkled with mineral crumbs. The material is easy to install and has the best performance among roofing materials in terms of roof hydroprotection. However, he also has disadvantages. Soft tile is a combustible material. This imposes certain restrictions on its use. It is also necessary to additionally isolate the roof slope when installing the chimney, for example. In this case, the chimney is equipped with a spark arrester.

You can read more about the installation of the chimney in the "Heating" section - there are drawings for the penetration of a soft roof with a steel and brick chimney.

Next in layers - lining material and plywood. Soft tile is a plastic and rather soft material. Therefore, it needs a solid base for roof mounting. Such a base is plywood, which takes on snow and wind load. At the same time, plywood is reliably protected from precipitation and ultraviolet radiation by bituminous tiles.

Plywood for the base under the roofing soft tiles should be chosen moisture resistant. This will avoid warping of the roof plane.

Plywood is mounted on the crate - this is the next layer of the roofing pie. For the crate, a board 100x25 mm or 75x25 mm is used. A board of greater width, such as, for example, for sheathing under a metal tile, is not used here - this does not make sense with a solid plywood base.

Under the bars of the ventilation gap there is a wind protection. It also performs the functions of waterproofing in case of possible leaks in case of damage to the roof. What is good about bituminous roofing is that even with strong side wind and rain, not a drop of moisture gets under the roofing material. Therefore, we put a windproof membrane with a hydroprotection function (just in case).

Next come the rafters. Sheets of roofing insulation are laid between the rafters. In the standard version of a residential building, the height of the rafter leg is 150-200 mm. It is of this thickness that the insulation is used (usually several layers of 50 mm each).

If this is not enough, then the next layer is provided - a crate of 50x50 mm bars for attaching an additional layer of insulation. Thus, it is possible to insulate the attic up to 250 mm of high-performance insulation.

Now consider the same drawing in the A-A projection (from the ridge to the overhangs):

Here you can clearly see how the cover is made. bottom layer additional insulation upper layers that are laid between the rafters. This allows you to unambiguously remove possible cold bridges, which in this design are wooden parts. truss system. Thermal insulation properties different breeds we have already considered the tree on the example of thermal conductivity tables on our website.

As can be seen in the second drawing, the bars of the ventilation gap are stuffed vertically on the roof - this ensures the flow of air from the bottom up (from the overhangs to the ridge) along the roof.

Roofing pie is a system of layers of various materials, which provide ventilation and vapor barrier, waterproofing and insulation.

Arrangement of a residential attic space

When building a private house, some owners even try to use the attic area for living quarters.

On the attic floors, in some cases, “summer”, that is, unheated, rooms are planned. But it is still preferable to have rooms in which full insulation is made and you can live comfortably not only in the warm, but also in the cold season.

Insulating material in attic spaces is usually installed on the floor: this helps to keep the heat that comes out from the floor below it. At the same time, an empty attic serves as a layer that does not allow cold to pass into the room from the roof.

When insulating an attic room, everything happens a little differently. All thermal insulation material from the floor is, as it were, transferred to the roof structure. Therefore, the roofing cake in buildings with attics will obligatory element designs.

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Roof insulation system

In the roofing insulation system, each of the layers is designed to perform a specific task. The working properties of the roofing cake will only be at their best if the order in which the materials are placed is observed. It is better to entrust its creation to specialists, but this does not mean that the owner should not figure it out on his own. In this case, he will be able to control how the work is being carried out and determine which materials it will be more profitable to purchase.

If the device of the roofing cake is not made according to the norm, there will always be large heat losses during operation.

In these cases, a large amount of condensate forms, in winter this leads to the constant formation of icicles and ice. In order for the insulation not to be done in vain, it is necessary to familiarize yourself not only with the sequence in which the layers of material are laid, but also with the characteristics of the materials before performing the calculations. This will allow you to calculate which of them should be selected for the layer.

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Roofing cake not insulated

This type of roofing cake design is created if the building has an insulated ceiling under the attic, and it is planned to be in the attic room only in summer. Here, the main task of the insulating structure will be to insulate the attic from condensate entering from the outside, so that the moisture can go outside. So that the microcirculation of air is not disturbed, a gasket should be made of a waterproofing perforated film.

When arranging an uninsulated roofing pie, the sequence will be as follows:

truss system device;
laying a waterproofing layer;
fixing the counter-lattice;
fastening the crate;
laying roofing material.

The insulated design includes large quantity layers. It is used for arranging residential attics and the task is not only waterproofing, but also ensuring the safety of heat. Under the roof, the thermal regime is much different from that on the ground floor of the building.

The roof itself summer time can warm up enough high temperatures, and in winter period often such a phenomenon as the freezing of the roof. In such housing, a comfortable atmosphere cannot be achieved. Roofing cake is arranged to perform the following tasks: keeping heat inside in winter, providing insulation for air that may come into contact with a frozen roof, and in hot weather, the cake does not let hot air inside.

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The structure of the insulated roofing pie

Rafter. All layers of the cake should be together about 35 cm. This must be taken into account when performing the rafter system. Decide on the material that you will lay as a heat insulator - this will help you find out if the height of the rafters will be sufficient.

It is the rafters that bear the main load of the gravity of the roof. Therefore, it is better to create them from coniferous trees, choosing such elements in which there are no flaws. The moisture content of wood should not exceed 22%. All wooden elements must be impregnated with an antiseptic. The pitch of the rafters and their thickness are chosen depending on what material is selected to cover the roof.

Vapor barrier. The actual installation of the roofing pie begins just from this layer. The last of the inner layers will be the finish.

Moisture must be present inside the housing. Most of all it is contained in the warm air, which, obeying the laws of physics, rushes up - into the attic. Ventilation is not able to ventilate to such an extent that all excess moisture is eliminated, they fall on the roof structure and settle in the form of condensate. The vapor barrier layer protects the insulation, arranged next, from moisture penetration. When saturated with moisture, thermal insulation loses its performance.

Among the materials used to create a vapor barrier layer, the following are most often used:

vapor barrier film. It is made multilayer, with the addition of a polymer reinforcing frame, which does not allow it to sag;
glassine is a vapor barrier with a democratic price, which has a significant disadvantage: over time, its ability to retain moisture disappears;
foil materials.

The latter are a film, one of the sides of which is pasted over with foil. There is also a material similar to chocolate wrappers, one side of which is foil, the other is paper. Both options perform not only a waterproofing function, but are also a good barrier to infrared radiation. It causes heat leakage from the room, and the foil layer helps to significantly reduce heat loss even without insulating materials.

Fastening the vapor barrier to the rafters is carried out as follows:

Rolled material is rolled along the rafter legs in the direction along the ridge. Laying should be carried out from below, with an overlap of 15 cm on the previous layer.
The film is attached to the surface with a construction stapler.
The joints of the material and the edge adjacent to the wall are sealed using a connecting tape or adhesive tape.

When laying the film, do not stretch it, it should sag slightly between the rafters.

Outwardly, it is impossible to distinguish a house with a pitched roof, under which an attic is equipped, from buildings with an attic, except perhaps by skylights. But if you delve into the design of the roof, you can find significant differences. Attic spaces are insulated only from the side of the ceiling, so as not to release warm air from the residential floor. Pie mansard roof contains many layers that allow you to create a microclimate favorable for living in the space under the roof.

First, let's figure out what is called a roofing pie. These are the necessary structural layers of the roof, which are laid in a certain sequence and are needed to insulate the structure, protect against condensation and moisture from the street, and also as a base for laying the roof itself.

The roofing cake of a cold attic and a warm attic is significantly different. In the first case, fewer structural layers are used. Usually this is rafters, waterproofing, lathing and roofing. When arranging residential attic spaces under a roof, the correct roofing pie consists of the following layers, arranged from bottom to top:

interior decoration premises;
vapor barrier layer;
rafter system and heat-insulating material, which is laid between the rafters;
waterproofing carpet;
clearance for ventilation of the under-roof space (it is formed by laying the counter-rail);
crate;
roof covering, namely the selected roofing material.

Each of the listed layers performs its own specific functions, so the absence of a layer or its improper installation can lead to large heat losses and significant costs for heating a house. Due to the accumulation of condensate, the insulation can become damp, and the supporting structures of the rafter system are quickly destroyed.

Important! It is worth remembering that not only the presence of a certain layer and its correct installation is of great importance, but also the choice of a suitable material in accordance with the features of the roof structure and the climatic conditions of the construction region.

Features of each layer

Next, we will consider the attic pie in layers, indicating the design features, as well as the nuances of the selection and installation of materials. We will consider all layers of the mansard roof structure, moving from the room to the outside.

The very first layer, which is located on the side of the room, is the interior decoration. For these purposes, you can use drywall sheets, plastic panels, wooden lining and other finishes. Among all materials for finishing the attic, drywall and wood have an advantage, since they can naturally regulate the humidity in the room, which contributes to a favorable microclimate.

vapor barrier

The vapor barrier layer is attached to the rafter system from below. It is needed to protect the internal structures of the roof and insulation from the formation of condensate due to the temperature difference between indoors and outdoors.

Attention! The absence or poor-quality vapor barrier leads to the accumulation of condensate moisture in the insulation. Due to dampness, the insulation cannot perform its heat-insulating functions, and it will be cold in the room.

Vapor barrier roll materials rolled out across the direction of the rafters and attached to them with a construction stapler. In this case, it is necessary to overlap the strips by 150 mm. The joints of the strips of material are additionally sealed with special tapes or ordinary adhesive tape.

The following materials are used as vapor barrier:

The most affordable and inexpensive vapor barrier is glassine. Over the years, its properties to protect against condensate moisture decrease, so it is better not to use it.
Special vapor barrier membrane. This is a polyethylene film, which may have additional reinforcing and reflective layers. She does her job well and does not sag.
Foil vapor barrier. This is the most expensive material, but in addition to protecting against moisture, it allows you to effectively retain heat in the room due to the reflective layer. The foil film must be fixed with a gap of 10-20 mm from the insulation. To obtain this gap, before fixing the film, slats of the appropriate thickness are stuffed onto the rafters.

Worth knowing: the vapor barrier should not fit snugly against the insulation laid between the rafters, so the material is attached to the rafters with a slight sag (about 2 mm).

truss system

For making rafters pitched roof in a private house, elements made of coniferous wood of at least grade 1 with a moisture content of not more than 15% are used. The optimal section of the rafters is 150x50 mm. In the middle climatic zone of our country, for effective insulation of a mansard roof, it is necessary to use heat-insulating material 200 mm thick. As you can see, the height of the rafters of 15 cm will not be enough, so a bar with a section of 50x50 mm can be attached to them from below.

The installation step of the truss system depends on the roof structure, the width of the used thermal insulation material and type of roofing. It is also worth remembering that the larger the step of the truss system, the larger the cross section of one element should be. For rafters with a section of 5x15 cm, the optimal pitch is 800-900 mm.

Important! All wooden elements of the supporting frame of the roof must be protected from rotting and burning. To do this, they are pre-treated with antiseptics and flame retardants.

insulation

The most important in the design of the attic roof is the insulation pie, because the comfort of living in the attic, as well as the level of sound insulation of the premises, depends on it. For thermal insulation of pitched structures, they usually use:

Mineral plates. They are made on the basis of basalt fiber, they are quite dense, non-flammable and retain heat well.
Fiberglass is a non-flammable, environmentally friendly material. Its disadvantage is the instability of the structure and the possibility of sagging.
Styrofoam is an inexpensive, efficient material that does not absorb moisture at all, but releases toxic compounds when burned.
Expanded polystyrene is a very light, non-flammable and non-toxic material that does not accumulate moisture. However, it has increased vapor permeability, so in the summer on attic floor there may be high humidity. Due to its high rigidity, expanded polystyrene is difficult to lay on difficult sections of the roof.

Tip: to insulate the attic, it is better to use soft mineral wool slabs based on basalt. They are easily mounted in difficult areas and fit snugly to the rafters without the formation of cold bridges.

For each construction region, the thickness of the heat-insulating material is calculated individually. The minimum layer of insulation is 150 mm. For regions with severe winters, it is necessary to use a heat-insulating material with a minimum thickness of 20 cm. In this case, the insulation is laid only on dry wood of the rafters. Otherwise, moisture will penetrate into the thermal insulation material and reduce its effectiveness.

Waterproofing

The main purpose of waterproofing is to protect the insulation from moisture penetrating from the roof, as well as the ability to pass water vapor, which will evaporate from the heat-insulating material. That is why a vapor barrier film is not suitable for these purposes, because it does not allow water vapor to pass through. For roof waterproofing, special materials are used:

diffusion membranes. These are films with microscopic funnel-shaped holes. The material is laid in such a way that the wide part of the funnel is turned towards the insulation, and the narrow part towards the roofing. In this case, it is necessary to create two ventilation gaps and lay the material from the insulation at a short distance so that the funnels are not clogged with water vapor. These membranes can only be used with roof coverings that are not afraid of moisture that collects from the back.
superdiffusion membranes. The effectiveness of this material does not require the arrangement of an air gap on the side of the insulation. Such films are suitable for houses where the roof is laid in an already inhabited building. The membranes protect well from the wind.

Important! Both types of membranes cannot be used with euroslate and metal tile coatings, since their back side must be reliably protected from condensate. But for coverings from soft and traditional tiles, these membranes are ideal.

Condensate films used for roofing made of euroslate and metal tiles, since they do not allow water vapor to pass through. In this case, excess moisture from the heat-insulating material accumulates on the fleecy side and is brought out through the ventilation gap. In such structures, it is necessary to provide a second ventilation gap between the waterproofing carpet and the coating so that condensate does not accumulate on the back of the roof.

Counter rail and crate

If it is necessary to equip the ventilation of the under-roof space, then the slats of the counter-lattice are stuffed over the waterproofing carpet. To do this, use a beam with a section height of 30-40 mm, which is nailed in the direction of the rafters.

Next comes a layer of framing. It can be continuous or sparse. The first option is equipped for soft roofing, for example, flexible tiles, and is made of OSB or moisture-resistant plywood. Between the elements of a continuous crate, it is necessary to leave a deformation gap of 2-3 mm. In the second case, boards 25 mm thick are used, which are nailed across the rafters in increments of 30-40 cm. After that, the roofing is laid.

It's not a very common design.

Such a structure should not only complete the integral structure of the building and perform the functions of protection.

But also to have a comfortable life in the room located under it.

In order for the living area to be suitable for use, it is necessary to understand the essence of the design of such a structure and the nuances of its installation processes.

A similar design has a number of elements, which constitutes an integral roof system.

The device of the attic roof looks like this:

Roof. Roofing necessary for providing reliable protection against the influence of atmospheric conditions both the entire house and the entire roof system.
. The supporting part of the attachment system, most often constructed from wooden boards.
Skate run. The very top of the whole system.
rafters. Supporting ribs that provide rigidity to the structure. They have two varieties - hanging and layered.
Mauerlat. The element is represented by beams, which serve to fasten the truss system. It repeats the element in the location of the perimeter of the house and is fastened to each wall with fasteners.
Diagonal piles. For that, so that the roof structure system has high level reliability, the rafters are interconnected by beams arranged longitudinally and vertically, which are connected together by diagonal ties or bevels.
Internal supports. An element that is located under each rafter leg and gives it stability.
insulating layer. Such a layer unites the entire roof system into a single whole, while creating reliable sealing, vapor and sound insulation. This layer has its own structure and is multi-layered. All materials that are used to equip this layer are necessary to provide all kinds of properties that ensure comfortable life in the attic.

What components and parts the mansard roof consists of, you will see in this drawing:

Mansard roof device drawing

roofing cake

Each type of roof has its own individual structure.

It is represented by several layers of different materials, which necessary to protect the attic from cold air masses And advanced level humidity.

Roofing pie mansard roof includes:

crate;
vapor barrier layer;
Control grate;
thermal insulation layer;
Waterproofing;
Ventilation systems;
Roofing material.

Each layer is designed to perform certain functions that are necessary for the normal operation of the entire roof system.

If you make mistakes during installation or neglect any of the layers, then this may lead to the need to redo the entire structure.

. The simplest type of roof over the attic, but not too popular. Represents one inclined plane, which is supported on load-bearing walls of various heights.
. Such a variety represented by two slopes, which are opposite to each other.
broken line. This type of roof has other names - and half-hip. This kind of design allows you to make the attic space optimal. There are four slopes in this design. It is quite convenient to live in the attic, having this kind of roof.
conical. The most complex view construction represented by a cone. Suitable for structures which have round or polygonal outlines.

Roof types

If we talk about the varieties of truss systems, then they are of 3 types:

Hanging type of rafters provide load transfer in a horizontal position to load-bearing walls. Such rafters are the basis of the entire system. There is no need for intermediate supports; wooden or metal puffs are used to connect the beams.
A layered variety of rafters is used in case of location bearing wall in the center of the building or the presence of intermediate supports. This kind of rafters is installed on the outer walls, while their middle part is supported by internal walls. Such a structure can only be built if the distance from the load-bearing wall to another is up to 6.5 m.
The hanging and layered variety of the truss system is represented by triangles having a right angle. Additionally, such a design is equipped with contractions from the bottom and top of the system. Hanging rafters are used to hang the ceiling.

Mansard roof: gable construction of a wooden house

Tilt angle

A very important parameter in the construction of the roof is to determine the angle of the roof. This value is determined not only by the design of the building, the features of the facade, but also by the chosen roofing material and local climatic conditions.

If the precipitation that falls on the area where the house is located is of great importance, then roof pitch ranges from 45 to 60 degrees.

This value of the slope will provide better snow removal from the surface., and, accordingly, a decrease in the load level. In addition to precipitation, this angle parameter protects the roof from glaciation.

If the house is located in an area in which a frequent occurrence is strong winds, That slope angle value should be minimum. Otherwise, the structure may be destroyed due to weather conditions. Under such conditions, variations of this parameter from 9 to 20 degrees.

However, the most common and optimal roof slope is 20-35 degrees.. This value is suitable for arranging a roof with almost any kind of material.

CAREFULLY!

The angle of inclination largely determines the durability and reliability of the structure.

Tilt angle

Mounting process

In order for the mansard roof, you must adhere to a certain sequence of actions:

Initially, the upper beam is fixed, which has section parameters of 10x10 or 15x15 cm. Fastening is carried out using nails, metal staples or self-tapping screws. At the same time, the first beam provides the function of the rafter frame.
The next one is installation of the Mauerlat, which is necessary to take most of the load. To install it, you will need a board with a thickness of at least 5 cm and a bar with section parameters of 5x10 cm. Before laying the board, cover a layer that is necessary to retain moisture and not destroy structural elements. Attach the Mauerlat with nails or staples and additionally tie it to the wall with a metal wire. The wire is mounted at the stage of wall construction.
Next install the rafters, choosing for this step from 0.6 to 2 m.
Gable rafters are installed first, after which they pull the level and begin to mount the remaining elements.
After rafter legs all installed provide additional structural reinforcement, connecting the rafters to each other in their upper part.
If the value of the roof length exceeds 7 m, then carry out the installation of the ridge beam. Otherwise, equipping a rafter system with a similar element is not necessary.
After installed go to the equipment of the layers of the roofing cake, having previously installed the crate.
The last stage in the construction of the roof is roofing installation.

Lathing installation

Rafter installation