Insulation of the attic from the inside if the roof is already covered. Attic

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. Roof covering is 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 the roof construction system has a high level of 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 space from cold air masses and high levels of 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 type of 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:

1. 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.
2. A layered variety of rafters is used if the load-bearing wall is located in the center of the building or if intermediate supports are present. This kind of rafters is installed on the outer walls, while their middle part is supported by the inner walls. Such a structure can only be built if the distance from the load-bearing wall to another is up to 6.5 m.
3. 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 strong winds are a frequent occurrence, then 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:

1. 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.
2. 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.
3. Next install the rafters, choosing for this step from 0.6 to 2 m.
4. Gable rafters are installed first, after which they pull the level and begin to mount the remaining elements.
5. After the rafter legs are all installed, provide additional structural reinforcement, connecting the rafters to each other in their upper part.
6. 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.
7. After installed go to the equipment of the layers of the roofing cake, having previously installed the crate.
8. The last stage in the construction of the roof is roofing installation.

Lathing installation

Rafter installation

Sooner or later, everyone who has already begun to build their house or is just thinking about building, has to deal with such unfamiliar words as “insulation circuit”, “rafters”, “vapor and hydrobarrier”. In search of answers, the concept comes that the roof is not only the visible part, which has an unusual shape and a beautiful coating. This, it turns out, is a multilayer structure with many main and auxiliary elements. And because of how well they work, the longevity of the roof and the house as a whole depends.

What is a roofing pie

It would seem that such a strange combination is a confectionery and a building term. But it is it that fully reveals the structure of the roof, its meaning and tasks - to protect the house from negative natural influences and provide a good microclimate in residential premises. And this is achieved thanks to numerous layers of insulating materials and additional components.

A roofing cake, where each element is in its intended place and performs the functions assigned to it, is the main filling of the roof. And the functionality of the roof depends on the correctness of its installation, namely the order of location and technology for attaching the layers.

A standard roofing cake consists of several layers arranged in a strictly defined order.

Video: roofing pie of a pitched roof, the role of insulating layers and ventilation

The composition of the roofing cake

The roof structure is equipped in two versions - under a cold attic space and under an insulated roof.

Cold roof device

A roof is considered cold, the space under which remains uninsulated and most often unused. There are times when it is deliberately left cold, such as to store canned fruits, vegetables, and foods.

For a sloping cold roof, the roofing pie is divided into two parts located in different zones.

The layers of the roofing cake of the cold roof are separated and equipped in different zones - on the slopes and ceilings

On the slopes, the layers of the roofing cake (from inside to outside) are as follows:

• waterproofing laid along the rafters;
• countertrays and crate;
• roofing.

On floor slabs (from interior to attic):

• ceiling lining;
• vapor barrier;
• insulation.

For flat attic roofs, the principle remains the same, except for the upper attic floor, which is usually not waterproofed. Most commonly used on flat roofs, soft roofing is itself a 100% sealant. Yes, and they lay it on a solid concrete base or profiled sheets, on which they arrange an expanded clay layer along the slope and a leveling cement-sand screed. This is enough to prevent any roof leaks.

The only exceptions are structures in which the attic roof is supported by a system of wooden beams. In this case, a waterproofing material is additionally laid on top of the wooden elements.

The waterproofing layer on flat attic roofs is laid only in structures with a wooden base

Cold roofs are considered the most correct, since they provide free air circulation, which, if necessary, is supplemented with roof aerators. Such a roof can last up to 100 years, keeping the truss system intact and usable.

Insulated roof

For an insulated roof with an exploited attic room, the roofing pie is characterized by the fact that all its components are combined into an integral structure with a strictly determined alternation of layers and ventilation gaps.

When viewed from inside the room, the arrangement of the layers of the roofing cake is as follows:

When arranging an insulated roof, special attention should be paid to the tightness of the joints of all roofing layers in hard-to-reach and therefore especially problematic places - walls, ventilation risers and chimneys, roof window flashings and valleys. Violation of tightness is fraught with the occurrence of cold bridges and heat loss through the roof.

Let us consider in more detail the layers of the roofing cake of a warm roof and their purpose.

Interior finishing of the under-roof space

The roof space in the form of an attic or attic is an interesting design. Even being luxuriously finished, it does not look solid. Often, sloping walls and ceilings give this room an aura of romance, airiness and lightness.

When choosing a finishing material, it must be taken into account that the truss system under the influence of wind and snow loads, seasonal temperature changes will still have signs of deformation. They will be very small and invisible, but they will have to be reckoned with in order not to get cracking of the joints on the cladding over time.

The main task of the finishing layer of the roofing cake is to ennoble the under-roof space and protect the next layer - vapor barrier - from moisture from the premises of the house. For cladding, they mainly use:

• blockhouse or lining;
• drywall (GKL);
• MDF or OSB boards.

Drywall is perhaps the most sought-after material for interior decoration, especially on complex broken roofs. It is easy to cut, thanks to which you can sew up elements of the most intricate shapes. In addition, drywall creates a perfectly smooth surface, which is subsequently easy to paint or apply beautiful decorative plaster. In addition, any decorative elements can be made from it and make the interior of the room incredibly attractive.

Plasterboard cladding elements can decorate the attic room and even divide it into zones

Attics and attics, sheathed with OSB or MDF boards, look no less beautiful. This material is as smooth as drywall, but much stronger.

Facing the under-roof space with moisture-resistant MDF boards using the play of light allows you to make unusual bright accents on individual elements of the interior

The big advantage of drywall and slabs is that hidden wiring can be mounted under them, but with the use of fire-retardant corrugations. But when sheathing with wood, the wiring will have to be made open and then decorated. But, despite this, many still prefer wooden running materials - lining and blockhouse with imitation of rounded logs or timber, as environmentally friendly materials that do not go out of fashion.

A classic-style attic sheathed with dark clapboard in combination with light walls looks strict and elegant

The main enemy of any insulation is steam. Rising from heated rooms, it meets cold air in the under-roof space, as a result of which it condenses and settles in the layers of the roofing cake. To prevent this, a vapor barrier layer is laid between the heat insulator and the inner lining. But in addition to protecting the insulation, the vapor barrier also retains heat in the under-roof space, which is especially important in the off-season.

As a standard option, a two-layer polyethylene film with a reinforcing mesh of polyethylene strips between the layers can be used as a vapor barrier.

The vapor barrier layer in the roofing cake is located between the inner lining and insulation

When choosing a vapor barrier material, you need to pay attention to the following points:

1. Tensile strength of a film or membrane. Insulation puts pressure on the vapor barrier material, as a result of which a thin film can tear, and then the condensate will do its dirty work.
2. Permeability index. If this coefficient varies from 0 to 90 g / m² per day, then this is a vapor barrier material. A coefficient over 100 indicates a vapor-permeable waterproofing agent, which is not suitable for installing a vapor barrier layer.

There is no universal "vapor waterproofing". Vapor barrier films or membranes and vapor-permeable waterproofing are different concepts, and their incorrect use will result in bad consequences for the whole house.

Thermal insulation material for roofing pie

Just as a person needs clothes, so the house needs protection from heat and cold. Therefore, thermal insulation is the simplest and most effective method of energy saving. Good thermal insulation materials can reduce heat loss by up to 70%. In addition, they provide:

• indoor comfort;
• effective noise and sound absorption;
• savings on heating and air conditioning costs at home;
• increase in the service life of the main structures;
• reduction of carbon dioxide emissions into the environment.

In private housing construction, mineral wool insulation is widely used - inexpensive, perfectly retaining heat and cool, chemically and biologically resistant. In addition, they have a fire resistance rating of over 1000°C.

When insulating the attic, mineral wool is laid in the gaps between the rafters

Recently, new insulating materials have appeared on the construction market.

1. URSA staple fiberglass is a wide-profile insulation that is easily installed in hard-to-reach places.
2. Extruded polystyrene foam, characterized by high heat and sound insulation, ease of use and long service life - up to 100 years.
3. Sprayed heaters, which are applied using special equipment and form an even layer on the surface with any geometry.
4. Styrofoam is the most budgetary option for insulation.

Styrofoam is widely used to insulate roofs and walls of a house because it is easy to install and inexpensive.

What insulation to choose, the owner decides. All of them deserve attention. However, to obtain the maximum effect, it is necessary not only to correctly select the insulation according to the roof structure, but also to follow the installation technology offered by manufacturers of insulating coatings.

Roof waterproofing

The next layer of the roofing pie is waterproofing, located above the insulation with an air gap to ventilate the latter. A waterproofing device is a necessary measure to protect the entire roof structure from precipitation. Lay waterproofing material throughout the roof, starting from the end of the rafter legs to the very ridge with the organization of the air outlet so that moisture does not remain in the insulation.

For roof waterproofing, a reinforced film is often used, which is laid along the rafters with a slight sag.

The waterproofing film is laid with a sagging between the rafters of no more than 20 mm. Membrane materials are mounted directly on the insulation without sagging, which significantly reduces the wind load.

Waterproofing materials must have:

• mechanical strength;
• good moisture resistance;
• elasticity and heat resistance.

In addition, it is not necessary, but it is desirable that they have heat-saving qualities. Protection from cold and moisture in one insulating material - a great solution for the home.

Ventilation gaps in the roofing pie

When arranging the roof, you need to remember - it must breathe well, regardless of its design. Otherwise, the roof will “cry” and no insulating layers will help. A warm roof is usually arranged above attic rooms, which do not allow providing the necessary space for free air circulation.

There are all conditions for natural ventilation of a cold roof in the attic, and when arranging a warm attic, it is necessary to provide for ventilation gaps

Therefore, when erecting an insulated roof, it is necessary to provide for the installation of three ventilation gaps in order to ensure full natural ventilation of the under-roof space:

1. Eaves channel along the entire length of the overhangs for the flow of cold air under the roof.
2. The space between the counter-lattice and the lathing for the movement of air along the roof.
3. Ridge vents through which warm air will go outside.

To enhance traction, natural air circulation is supplemented with ventilation roofing extensions - aerators, valves or turbines.

Roof aerators supplement insufficient natural ventilation of the under-roof space

Roof anti-icing system

The eternal struggle with ice and snow these days is solved quite simply. For this, modern roof anti-icing systems have been created, which have replaced mechanical snow removal with a shovel and scrap and chemical treatment. Unlike the last two methods of snow removal, in which there is a high probability of damage to the roofing, anti-icing systems are completely safe and highly effective. However, they have their drawbacks:

• additional power consumption;
• high cost;
• the need to attract professionals who will competently carry out calculations, installation, testing and debugging of the entire system.

Video: heating the roof, gutters and gutters with an electric cable

roofing material

Every developer wants to see their home bright, individual, eye-catching and flawless in everything. And if the facades are still revetted in a moderately restrained way, then the roof more than compensates for this. Fortunately, modern roofing materials are an expanse of fantasy that can give any home style and character.

A huge variety of textures and colors reigns in the world of roofing today. If you want a roof that matches the tone of young greenery or you like a bright orange color - no problem. Red, lilac, red, yellow, blue - whatever your heart desires.

The rich blue color of the bituminous tile roofing looks beautiful against the background of a light facade

But, when choosing a roofing, it is worth remembering that the key requirements still remain:

• fire resistance of the covering material;
• wear resistance, strength and durability;
• ease of installation and availability.

And only after that comes the turn of aesthetic criteria.

Video: an overview of popular roofing, their pros and cons

Varieties of roofing cake

It should be noted that the structure of the roofing pie may vary. Depending on the roofing and the type of roof, some layers are missing or partially laid, while others appear additionally, which is dictated by the characteristics of a particular structure.

Types of roofing cake depending on the roofing

Consider the composition of the roofing cake for the most popular covering materials.

Decking is the most unpretentious material, so it will not be difficult to equip a roof under it on your own. Particular attention should be paid to two layers - thermal insulation and sound insulation.

The insulation is laid strictly in the inter-rafter space. To improve the performance of the heat insulator, it is covered with a windproof film that does not allow steam to pass through, and a crate is stuffed, on which profiled sheets are already mounted. The step for the crate is chosen according to the size of the sheet and the slope of the roof, taking into account the overlap in one or two corrugations. Features of a metal roof require:

1. Mandatory arrangement of ventilation gaps between the insulation layer and the roofing. The size of the ventilation ducts is not fixed, but not less than the beam thickness of the crate (3 cm).
2. When assembling the crate, it is desirable to install additional stiffeners, which will significantly prolong the operation of the roof.

The installation of insulating strips of felt or polyethylene foam along the rafters will help to solve the problem of sound insulation.

The standard composition of the roofing cake for corrugated board:

Roofing cake for flexible tiles

Soft tile has a great advantage - it is an absolutely waterproof material. Therefore, there is no waterproofing among the layers of the roofing cake, but additional layers appear - a solid base made of moisture-resistant chip materials and a lining carpet.

A pie is arranged under the tiles by alternating the following layers:

The original roofing materials of the Ondulin company do not require a roofing pie as such. They do not care if there is an insulating layer and vapor or waterproofing films, or not. They themselves reliably protect the roof from the weather, if the rafter system, the crate and, if necessary, the counter-lattice are correctly installed. In addition, branded materials retain heat well. This is what we talked about in the "Waterproofing" section: two significant functions in one material - the ideal solution to the issue of waterproofing and thermal protection.

Of course, in our frosty winters in houses of permanent residence, the roof must be insulated. Nevertheless, under ondulin, no special requirements are imposed on the insulation. Except for one thing - its thickness must comply with SNiP standards. For example, for Moscow and the region, this is at least 25 cm of mineral wool material.

The sequence of layers from the roofing to the inside of the room:

Roofing pie under the metal tile

The seam roof with a matt finish in gray harmonizes beautifully with the wooden architecture of the house in the same color scheme.

Roofing cake under the seam roof:

Video: seam roof installation

The pitch of the rafters for a sloping roof is determined by the roof structure and covering material, the recommended value is from 600 mm

Video: rules for installing a roofing pie

The roofing cake fills the truss frame. It is necessary to protect the house from rains, showers, keep warm, do not miss the noise. This is due to the fact that the roofing cake is multi-layered, it has forming elements, they need to be laid correctly and alternately, and at the same time, the fastening technology must be observed, then the roof will be multifunctional.

Each layer of a roofing cake under a metal tile with an insulated roof is designed to perform a function, the cake should be mounted in a strict sequence. At the same time, the main rule is that its mass should not be more than the bearing capacity of the rafters. Therefore, it is worth calculating all the loads on the building envelope, the required thickness of the insulation and the strength of the rafters using ours.

Typically, a roofing cake includes: (from inside to outside):

• filing from the side of the roof space;
• vapor barrier, for example, polypropylene film;
• insulation, for example, mineral wool, placed between the rafter system;
• waterproofing, for example, a membrane that is laid along the upper edge of the rafters;
• a counter-lattice made of wooden slats;
• crate made of wood;
• covering material, that is, a metal tile.

The roof can be insulated in different ways, it can be cold or insulated.

That is, the roofing cake consists of certain layers, with each layer performing its own function:

1. The topmost layer of the pie is a metal tile. It provides protection from precipitation, temperature changes, determines the appearance of the roof.

2. Vibration isolation elements. They stop the vibration, with them there is no noise from a downpour knocking on a metal roof.

3. The frame of the lathing is made of wood. It is required to attach the outer covering - metal tiles and make a gap under the roof so that ventilation exists between the materials.

4. Counter-lattice, consisting of wooden slats. Provides necessary air circulation between a metal tile, an obreshetka and insulating materials.

5. Waterproofing. It does not allow moisture to penetrate to the frame of the truss system and into the insulation.

6. Thermal insulation material. It performs the function of isolation from noise and does not allow heat to escape from the room.

7. Roof rafters. A roofing cake and insulation are attached to them. With the help of the rafter system, free space is obtained in the attic.

8. Vapor barrier. She brings out the vapors that form inside the house.

9. A layer of inner lining of the roof. It is intended for fastening of finishing material.

Rafter.

Metal roof rafters are identical to other rafters to which sheet or heavy coverings are attached. But these rafters are different in that the metal tile does not load them very much, so for the construction of rafters it is not necessary to take a beam of large section.

The distance between the rafter legs is usually 600-900 mm. When choosing the pitch of the rafter bars, it is worth considering the width and thickness of the material used for insulation. It must be tightly laid between the frame, so that there are no gaps.

The rafter system is made of bars with a section of 50x150 mm. If the boards have this width, then you can choose a heater with a thickness of 150 mm. If you want to build a roof in the cold regions of the country, then you should select bars with a width of about 200 mm. Then you can pick up a heater also 200 mm thick.

Vapor barrier.

Vapor barrier is required to protect the insulation from moisture, as well as to maintain a certain microclimate in the rooms. Usually, the steam generated in the room rises. If there is no vapor barrier layer in the installed roof, then the steam will be absorbed into the insulation.

During frost, the steam will begin to stop from the outside of the thermal insulation. There it will first become frost, and then a crust of ice on the material. And in the spring, when it becomes warm, the insulation covered with a crust of ice will become unusable. The ice will melt and water will flow onto the insulation. Previously, glassine was used as a vapor barrier. Now they are mounting films made of polyethylene or polypropylene:

1. Polyethylene film is not very strong, because of this it is reinforced with mesh.

2. A polypropylene film is a woven fabric, it is laminated on both sides with a thin layer of the same material. One side is rough.

Thermal insulation.

The most widely used heaters are mineral wool or polystyrene. They are pretty inexpensive. Mineral wool, foam blocks are laid between the rafters. They are mounted end to end. If this results in cracks and gaps, then they are blown out with mounting foam.

If you do not have time to install insulation, then you can insulate the roof with polyurethane foam.

Waterproofing.

Previously, glassine or roofing felt was used as waterproofing. Now, in order for the roof to last for a long time, special membranes are used. Although this material is not cheap, it is reliable and durable. The membrane material consists of 2 layers: the first is reinforcing, the second is moisture repellent.

Control grate and ventilation gap.

The counter-lattice is created from wooden slats. They are attached to a layer of waterproofing, which is placed on top of the log rafters. Then the mounted bars of the counter-lattice provide a gap between the waterproofing layer and the roof covering.

Crate.

The crate is the basis for attaching the metal tile. It is made of wooden blocks, they are mounted perpendicular to the legs of the rafters. Reiki, boards or bars of the crate are attached end-to-end or through a small gap equal to the step of the wave of the metal tile. A crate made of wood is created by attaching it with nails, screws, staples.

But in this case, you should not forget that the whole tree should be treated with antifungal compounds, otherwise it will rot.

Vibration isolation.

You should definitely make vibration isolation if you plan to cover the roof with metal tiles, since during rain, showers, quite a lot of noise appears.

Sound-absorbing materials are used to protect metal roofs from noise.

To reduce noise and vibration, you can:

1. Tightly attach all layers of the roofing cake, thus increasing its rigidity. This is easy to do if, when attaching, screw in a lot of self-tapping screws by 1 m.

3. Make the crate and the counter-crate in the same plane. Since if the slats are attached unevenly, then after the installation of the metal tile, the final coating will be deformed, and this may cause noise.

4. You can also reduce noise if a seal is placed between the counter-batten and the rafters, which isolates sounds.

For the manufacture of metal tiles take thin sheets of aluminum, steel, copper. If you are planning to buy a metal tile in Kyiv, we recommend that you follow the link where you will find your option for buying a roof at a great price.

Such material can serve as a roof for several decades, it is reliable and durable. True, such properties depend on the density of laying metal tiles when creating a roof. To put the material tightly, sealing elements are used.

Video lesson of metal tile installation.

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 the waterproofing material, for the purpose of economy or out of ignorance, is not overlapped. 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 roofing pie scheme

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.

A house with a mansard roof is the most common solution for private construction. Building a mansard roof at home is a relatively simple and inexpensive way to increase the living space of a building. Mansard roof (or attic) - a type of pitched roof, the under-roof space of which is large and is used as a usable area. The slopes of a classic mansard roof consist of two parts: the lower ones are steep and the upper ones are more gentle.

Types of mansard roofs

• Attic with gabled roof. We are talking about the usual gable roof, the attic of which is equipped as a living room. The advantage is ease of installation and minimum cost. No complex calculations required. Minus - the area of ​​\u200b\u200bthe resulting room is small with a sloping vault.
• Attic under a gable sloping roof. Classic variant. Such an attic has four slopes. The two lower ones are at a steep angle, the two upper ones are more gentle. Structurally more complex. Plus - a large usable area.
• Attic with a remote console. The design feature of the attic is a frame extended beyond the main room. Requires complex calculations in design and construction. A plus. We get a completely normal living room in which you can install vertical window structures.
• The attic is multi-level. A feature is the complex design of the truss system. The emphasis of the roof falls on different points. In most cases, such an attic looks like a continuation of the walls of the house itself.

Mansard roof requirements

The mansard roof will serve for a long time, without major repairs, if the following rules are observed during installation:

• 2.2 m - the minimum height of the attic room.
• Reinforced insulation to equalize the degree of thermal insulation of roof slopes with the walls of the house.
• Efficient ventilation of the roof layers will ensure a normal level of humidity.
• For the topcoat, it is better to choose materials with a low specific gravity, so as not to weigh down an already difficult structure.
• The construction of the attic must be included in the building project in order to calculate the increased load on the load-bearing walls of the building.

Warm roof

The mansard roof must be warm. Recall that pitched roofs can be warm and cold. The difference between them is the composition of the roofing cake. A warm roof involves the insulation of roof slopes, as well as equipment for hydro and vapor barriers.

For roof insulation, you can use any type of insulation: expanded clay, polyurethane foam, expanded polystyrene, foam concrete, foam glass, cellulose and basalt fiber insulation. Basalt mats are the most popular.

The insulation is placed in the space between the rafter legs. To enhance the effect, you can put in two layers. In this case, the second layer is spread so as to close the joints between the mats of the first. A reinforced waterproofing layer is required. The lack of cotton wool - when moisture gets in, they can not only lose their heat-saving qualities, but also increase the load on the truss system.

Do not allow the heater to get wet. A vapor barrier membrane is placed on top of the mats to prevent evaporation from the interior from condensing on the inner layers of the roof. To protect the insulation from condensate, the formation of which is possible on some types of roofing materials, for example, steel, waterproofing is laid between the roofing and the insulation.

As a waterproofing, a film or membrane is used. The use of the latter is preferable. The material has excellent diffusion properties. It is impervious to water, but perfectly passes steam. Thanks to this, water evaporating, pass through the layers of the roof, without settling anywhere. In addition, membranes are more practical in terms of space saving. Unlike films, they do not need to leave a gap between layers. It fits directly on the heater.

First of all, the valley is processed. From top to bottom, the membrane is laid along the entire length. The joints are glued with a special tape, preferably of the same brand as the waterproofing. Rolls of waterproofing membrane are rolled out horizontally from the eaves towards the ridge. Individual canvases are laid with an overlap of 15 cm. Joints are made on the rafters. The material should be well stretched, without sagging.

Styrofoam boards can be used to insulate roof slopes. Compared to mineral wool, they do not absorb moisture in the event of a leak in the waterproofing system.

Foam boards are laid between the rafter legs on the crate. The width of the rafter pitch can reach 2 m. It is laid without a gap. The minimum layer thickness is 100 mm. The maximum is not strictly defined. The thickness of the insulation layer is calculated for each specific case, taking into account the climatic features of the area where the house is located.

Plates are attached with glue or dowels. If gaps have formed between them and the rafters, they are filled with sealant or mounting foam. You can't leave it open. Cold bridges form in them, which leads to the formation of condensate. The result is the appearance of mold and rotting of the rafters. A vapor barrier is laid on top of the foam boards and sewn up with clapboard, wood board or drywall. Depends on the functional purpose of the roof space.

Ventilation system

For a mansard roof, the issue of ventilation is no less important than insulation. If the movement of air is difficult, then the room will have high humidity, and the layers of the roofing cake will quickly fail.

The ventilation of the mansard roof is carried out due to the natural movement of air. In a properly designed roof, air flows from the bottom up - from the eaves to the ridge. The easiest way to ensure ventilation of the attic is the correct alternation of roofing layers, leaving ventilation gaps. If you look at the roof from the room, the layers are placed in the following order:

1. room ceiling;
2. clearance 5 cm;
3. vapor barrier stuffed from the inside of the rafter legs;
4. insulation laid between the rafter legs;
5. crate and counter-batten - a key layer for the free passage of air flows. It is here that the main gap for ventilation is formed;
6. waterproofing;
7. roofing.

The arrangement of the ventilation system of the attic roof may differ in the layout of the waterproofing layer and the film that is used as this layer. Based on this, two- and single-layer ventilation are distinguished.

Single layer system

Distinctive features:

• waterproofing is laid directly on the insulation;
• membrane fabric with a permeability of 800-1000 g per 1 sq / m per day is used as a waterproofing.

The advantage of the membrane lies in the ability to pass water vapor coming from below, but not to pass water, which condenses on the roofing and drips onto the film.

Two layer system

The peculiarity of this system is that air flows along both surfaces of the waterproofing film: from above and below. The film is laid in such a way that a gap is formed after the insulation layer and before the roofing material. For the operation of the system, ventilation slots are left along the eaves and the ridge, or ventilation grilles are installed in the eaves.

Additional ventilation

If the natural ventilation system cannot cope with air purification in the attic room, it can be helped by installing additional funds.

1. Ridge aerator. A roofing element that is installed instead of the ridge along the entire length. The aerator is supplied with lattices which protects it from hit of garbage.

2. Cornice products. Can be done in two ways. The first is to leave ventilation gaps when filing the cornices. The second is to insert perforated spotlights, plastic or metal, into the filing of the cornices.

3. In cases where the installation of products is carried out already on the finished roof, ventilation grilles can be used. Holes are cut in the cornices, in which gratings are fixed with self-tapping screws.

4. Roof aerator. It can be mounted already on a completely finished roof. It is a plastic tube with an umbrella at the top. For mansard roofs, it is recommended to use a reinforced version of the roof aerator. It is equipped with a fan that creates a reduced pressure, due to which moisture and steam are effectively removed from the living quarters and the roofing cake.