Methods and features of attic insulation. How to insulate the attic floor for winter living: do it yourself Insulation of the attic ceiling from the inside with your own

The roof is one of the most important structural elements of a building. It is influenced by various factors. environment. Protects the house from high and low temperatures, atmospheric precipitation, solar radiation. If the roof is not insulated in accordance with building codes, heat loss through the roof can reach a third of the total heat loss of the house. Warming mansard roof not such a simple process as it might seem, although it is doable with your own hands. If your house has attic floor, the question will inevitably arise how to insulate the mansard roof. Many owners prefer to make an extra room there. First, it increases the total living area of ​​the house. And secondly, there is a new original room. During the construction of modern cottage settlements, attic rooms are planned initially. But even in old houses, you can easily convert the attic with your own hands into a living space.

The insulating material used for the attic roof, in addition to keeping the house warm, protects against acoustic vibrations. Therefore, it is important to decide how best to insulate the attic roof.

First you need to decide how to insulate the roof of your attic. To date, there are many options for thermal insulation materials. Mounting them is easy to do with your own hands.

Thermal insulation should contribute to maintaining a favorable atmosphere in the room. In winter, the house should be kept warm, and in summer - cool.

There are many nuances in the installation of the roof itself. The walls of the attic room are either the gables of the building or the slopes of the roof, or are adjacent to the slopes. That is why the intensive movement of air through the roof begins. Because of this, it is constantly exposed to temperature changes. To avoid the above problem, attic insulation must be carried out in sequence (from the inner layer to the outer layer):

1. Vapor barrier layer.
2. Heat insulating layer.
3. Ventilation gap.
4. waterproof layer.
5. Directly roofing material.

If high-quality insulation of the mansard roof is carried out, then the absence of the above layers is not recommended. Of particular note is the role of the heat-insulating layer and the ventilation gap. It is thanks to the presence of all layers that the microclimate in the attic room is provided.

What to look for when choosing a heater

When choosing a heater, you should first look at thermal conductivity. This is the ability to give and absorb heat between the attic space and the surrounding air. A material with low thermal conductivity is desirable. Firstly, it will contribute to better protection of the house from heat leaks. And secondly, a thin layer of heat-insulating material is required.

Properly insulated attic

On the other hand, if the attic roof is not adequately insulated, problems begin in winter. During the winter months, the roof is covered with a layer of snow. Snow is a good additional heat-insulating layer. But with insufficient insulation with your own hands, heat is lost through the roof. The snow is gradually melting. A layer of ice forms. Ice is unable to retain heat. It has a mechanical effect on structures. Including on the outer covering of the roof. This leads to its wear and gradual destruction. Sometimes because of this, it is required to repair the outer roofing layer after each winter. With sufficient thermal insulation, snow does not melt and does not turn into ice in winter. The roof retains its structure, and the snow provides additional protection against heat loss. In summer, the situation is reversed. Under the influence of direct solar radiation, the roof tends to heat up and a suffocating atmosphere is created. If you lay a layer of insulation in sufficient quantities, this problem will not be, and a comfortable environment is provided in the attic.

The main characteristics of heaters

When deciding how to insulate the attic roof of a house from the inside, in addition to thermal conductivity, it is necessary to pay attention to several more important parameters of the insulating material. The most important characteristics:

• water resistance;
• weight;
• fire safety;
• durability;
• material thickness;
• environmental characteristics;
• terms of operation.

Moisture resistance is usually specified by the manufacturer of a particular material. It is an important parameter, since the roof can leak and get wet. Therefore, it is desirable to choose a material with water-repellent properties. If this is not available for one reason or another, then the layer will have to be additionally waterproofed. Also has great importance material weight. The smaller it is, the better. The total weight of the material is determined based on its relative density. Mineral wool materials should be with a density of 45 to 50 kg / cubic meter. When using fiberglass, the density should be within 20 kg/m3. Heavier materials will put excessive pressure on structures.

Insulating layers must be non-combustible. This is usually reflected in the technical documentation. As for durability, the ability of the insulation to maintain its shape for many years is important. After all, the roof can be multi-pitched. If the insulation is deformed, the roof will simply lose its protective properties.

What materials are popular

It is necessary to disassemble each separately in order to decide how to properly insulate the roof of the attic. Main materials:

• Styrofoam;
• extruded polystyrene foam;
• polyurethane foam;
• mineral wool;
• glass wool.

The better to insulate the attic roof, you decide. But before that, you need to familiarize yourself with each material.

Styrofoam- this is a sought-after material among people who are faced with the problem of how to properly insulate a mansard roof. It has suitable thermal conductivity, low density and, accordingly, low weight. Styrofoam provides good protection from water, it is quite inexpensive. On the other hand, it has certain disadvantages. Its main disadvantage is the lack of fire safety. Also, when installing with your own hands, it often crumbles. As a result, gaps appear between the rafters. This, in turn, leads to a decrease in the thermal insulation characteristics of the coating. Styrofoam also has a short service life.

Extruded polystyrene foam has the best features. Firstly, it is non-combustible and provides the necessary fire safety. Doesn't crumble over time. Has water repellent properties. The advantage is also that a very thin layer of material is needed. The material is not recommended to insulate living quarters.

polyurethane foam differs from the previous options in the way of laying. This leaves no gaps. The material retains its shape very well. It has the necessary fire safety and repels moisture. The disadvantage of polyurethane foam is the poor ability to pass vapor. Because of this, there may be increased humidity in the attic room. The problem is solved by the organization of adequate ventilation.

Mineral wool and glass wool commonly known as insulating materials. They have many advantages. Excellent fire safety, keep heat well, have a low density. Do not leave cracks and gaps when laying. The material provides excellent sound insulation, has a low price. The disadvantages include high moisture absorption and vapor absorption.

Important: installation of glass wool is carried out in closed clothing, a mask and gloves. Contact of material particles with skin and mucous membranes should be avoided.

Laying heat-insulating material

When insulating the attic, do not forget about hydro and vapor barrier

After selecting the material, it is necessary to prepare the premises for installation. Insulation of the attic roof begins with determining the step of laying the insulation. We must try to ensure that the sheets of insulation fit closely between the roof rafters. This will avoid the formation of gaps and further heat loss. If you are using foam, then this nuance does not matter to you. Waterproofing is laid with an overlap between the rafters and the crate. Then, with the help of screws, wooden panels are installed to provide ventilation. The insulating material itself is mounted directly on the created platform between the rafters.

Tip: the rafters themselves let heat through. It is necessary to lay an additional thin layer of insulating material on top. Be sure to remember the location of the rafters.

This is useful when attaching various structures in the attic room.

Video: brief abstracts of proper thermal insulation with mineral wool insulation

Thus, it is not difficult to insulate the roof. To do this, you need to choose suitable material which suits you. And then, in accordance with the technology, mount the insulation. As a result, a favorable climate for living will be created in the attic room.

Mansard roof insulation is one of the key steps in creating a reliable roofing pie, which is designed for a long service life. To ensure comfortable conditions for year-round living in the attic floor of the house, it is important to choose a high-quality insulation and properly install it.

Functional features of the thermal insulation layer of the roof

Properly executed insulation of the roof structure from the inside makes it possible to provide a favorable microclimate in the attic room. In the cold season, heat will be effectively stored there, and in the heat, thermal insulation will not allow overheating of the air in the rooms under the mansard roof. To create effective roof insulation, you need to understand the intricacies of the roofing pie installation technology and use high-quality materials and tools. An introductory video is helpful.

Insulation of mansard-type roofs is carried out according to the same principles as the insulation of ordinary roof structures, but increased requirements are imposed on mansard roofs. This is due to the design features of the attic rooms, the walls of which are either formed by the slopes of the roof and the gables of the house, or are closely adjacent to the slopes. For this reason, the air in the attic in the summer heat is very hot, and cools quickly in winter.

The mansard roof multi-layer cake consists of the following components (from the inner layer to the outer):

• vapor barrier layer;
• insulation;
• gap for ventilation;
• waterproofing;
• roofing material.

The presence of all layers is mandatory, since each of them performs a strictly defined function. Increased attention is required for ventilation and the heat-insulating layer of the roofing pie, since the level of comfort when living in the attic floor of the house depends on their quality performance.

When choosing a heater, it is necessary to pay attention to such an indicator of the material as thermal conductivity.. It characterizes the ability of a material to transfer heat into or out of a room. The lower this indicator, the better the material protects against heat leakage, therefore, the smaller the insulation layer can be used to achieve the required thermal insulation characteristics of the roof.

In a heated room, the greatest heat loss occurs through the roof, since, in accordance with the laws of physics warm air rises up. Heat penetrates through roofing cake and transferred to the finish coat, which is covered with a layer of snow in winter. Snow has a porous structure, and due to internal air pockets, it acts as an external heat insulator at air temperatures below -2 degrees.

If the heat loss of the house through the roof is large, the roofing material heats up, which causes the snow to melt. When the air temperature drops, the melted snow forms an ice crust. It's dangerous for roofing, since when freezing, water has a negative effect on the outer surface of the roof. Ice, unlike snow, is not a thermal insulator, in addition, it is denser in structure - the ice crust on the roof significantly increases the load on structures. If the insulation from the inside is done correctly, in winter the snow on the roof does not melt.

In hot summer period excess heat is transferred from the roof to the inside of the room. The air can overheat so much that even air conditioners will find it difficult to maintain a normal microclimate on the attic floor. Installing a reliable heat-insulating layer from the inside of the roof will avoid such problems. Of course, the air in the attic will be heated more than in the rooms on the first floor, but the difference will not become uncomfortable.

Features of mansard roof ventilation

Mansard roof insulation requires a special approach. This is due to its design features. If we compare the device of an ordinary roof and an attic, it is obvious that the main difference is the size of the ventilation space between the living quarters and the roof. Ventilation of a conventional roof is provided by the presence of an attic with dormer windows. The ventilation space of the mansard roof is very limited - it is only about 10-15 centimeters.

Properly performed ventilation is extremely important when arranging a mansard roof roofing pie.. The ventilation gap between the waterproofing and the insulation helps to remove excess moisture from under the roof, protecting the entire structure and extending its service life. AT winter period ventilation prevents overheating of the roof and the formation of an ice crust on it. In hot weather, due to the ventilation from under the roof, part of the heat is removed, thanks to which it is possible to avoid overheating of the air in the attic floor and the structural elements of the roof.

The choice of insulation

At the stage of preparation for the installation of the roofing cake, you should decide on the choice of material for insulation. From the right type and specifications depends on the number of layers and the thickness of the thermal insulation. On the modern construction market, wide range of materials for insulation of roof structures. Among the most requested are:

• polyurethane foam;
• extruded polystyrene foam;
• glass wool;

Foamed glass can also be used, different kinds natural insulation for installation from the inside (wood chips, seaweed, granulated paper, etc.).

There are four main criteria for choosing a thermal insulation material:

• coefficient of thermal conductivity;
• moisture resistance;
• fire resistance;
• environmental Safety.

Note! To insulate a mansard roof, it is recommended to use a material with a thermal conductivity coefficient of 0.05 W / m * K and below.

The higher the moisture resistance of the insulation, the longer it will retain its functional qualities. The index of resistance to burning is an important criterion for ensuring the safety of the house. It is also important to consider the environmental friendliness of the material and its safety for humans. But the last two parameters do not affect the durability and effectiveness of roof insulation.

Mineral wool - a heater made from a melt of rocks. The material holds heat well, does not rot, is resistant to temperature extremes and aggressive environments, and practically does not absorb moisture. Mats of various thicknesses made of mineral wool are especially convenient to use for roof insulation if the pitch of the rafters matches the width of the mat.

Glass wool is made from molten glass, in terms of its properties this type of insulation is close to mineral wool, but has a lower thermal threshold of -450°C. It has good heat and sound insulating characteristics. Glass wool is frost resistant. Moisture can accumulate between the glass wool fibers, so waterproofing must be done correctly.

Mineral wool and glass wool allow you to insulate the roof with minimal financial investment. The disadvantages include the need to create a thick layer of insulation and several layers of vapor and waterproofing.

It is possible to insulate the roof structure from the inside with the help of polymeric materials - expanded polystyrene or polyurethane foam. The advantages of polyurethane foam (gas-filled plastic) include a high ability to retain heat, lightness, and durability. Polyurethane foam does not pass steam and is not affected by moisture. Extruded polystyrene foam allows you to effectively insulate the roof - its thermal conductivity coefficient is 0.05 W / m * K. The material has hydrophobicity, does not pass steam. Flammability class from G1 to G4, depends on the brand of material. The disadvantages of polymer insulation include their artificial origin and relatively high cost.

If there is a goal to build a house exclusively from eco-friendly materials, you can insulate the roof with natural heat insulators. Despite good thermal conductivity and environmental friendliness, various types of natural insulation have their drawbacks. Foamed glass is highly brittle. Granular paper, as well as mats made from reeds, straw, seaweed and similar materials, are highly flammable and require special skills during installation.

Insulation installation technology

To understand how best to install thermal insulation when arranging a roofing pie, you need to familiarize yourself with step by step instructions work. In general, it boils down to the following actions:

• preparation of space for the installation of insulation;
• laying a heat-insulating layer;
• material fixation.

At the stage of project preparation roof structure you should determine the step with which the rafters will be installed. In this case, it must be borne in mind that the rafter system must be reliable, that is, the step should not exceed the recommended values. If the type of insulation is selected in advance, it is recommended to install the rafters in such a way that the mats or insulation boards fit tightly between them from the inside. This simplifies the insulation technology and minimizes the waste of thermal insulation material.

Above the thermal insulation, between the crate and the rafters, waterproofing is laid. The material is overlapped, laying starts from the bottom edge of the slope. Then wooden counter-battens are mounted - their thickness creates the required ventilation gap of the roof. Reiki can be attached to the rafters with nails, but it is better to use self-tapping screws. Insulation is laid and attached to the prepared structure from the inside between the rafters.

A rafter leg made of metal or wood is a cold bridge, since its thermal conductivity is much worse than that of a heat insulator.

For this reason, when insulating the attic, you should not limit yourself to installing a heat insulator between the rafters - it is better to make a continuous heat-insulating layer on top of the already laid mats and rafters. For a continuous layer, it is better to use a thinner insulation. This method improves the quality of insulation. The disadvantages include the fact that in this case the rafters are hidden, and it is more difficult to use them in the future to fasten other structural elements. To facilitate the progress of further work, the location of the rafters should be correctly noted.

A vapor-permeable film should be laid on top of the thermal insulation. Its use allows you to remove excess moisture. Then the prepared structure is fastened with a crate. At the final stage of work, the inner lining of the ceiling is performed. Properly executed roof insulation allows all year round use the attic floor as a living space in which a favorable microclimate is maintained. For a detailed answer to the question of how to insulate a mansard roof, it is recommended to pay attention to the thematic video with detailed instructions.

Statistics show that more than 50% of residential under-roofing premises in the Russian Federation are insulated with mineral wool. Does the popularity of the material speak of its undeniable advantages? This review considers the insulation of the attic from the inside with mineral wool with your own hands and analyzes the method from a functional and technological point of view.

Slabs, mats and roll materials made of basalt fibers, used to insulate the attic from the inside, attract developers and builders with three important properties:

Mineral wool is an effective and popular insulation in Russia

• Fire safety. All grades of mineral wool are classified as NG.
• Vapor permeability.
  

  Due to the ability to absorb condensate and evaporate it when the temperature rises, mineral wool works great in contact with wooden rafters. It protects them from waterlogging, which is the cause of the development of fungus and rotting of wood.

• Good noise-absorbing characteristics. Randomly oriented fibers most effectively reduce the level of high-frequency noise, which is especially annoying and annoying when it rains.

The described characteristics, to a much greater extent than the cost, influence the choice of this type of insulation for attic insulation. However, different brands of basalt thermal insulation differ significantly from each other in a number of other parameters. Do-it-yourself insulation of the attic from the inside of the room requires a certain amount of experience with mineral wool and imposes additional restrictions on the properties of the material: this becomes clear from the video posted in the "Self-Assembly Algorithm" section.

These additional features include:

1. material format. For laying between rafters, the width of the thermal insulation should be 600 - 610 mm.
2. Density. When working alone, the less the plate or its segment weighs, the better.
3. Elasticity and sufficiently high rigidity. This quality greatly simplifies the insulation of the attic with mineral wool.
4. The presence of large thicknesses - 100, 150, 200 mm.

It is a common misconception that a high density of basalt insulation indicates its increased energy efficiency, and a low density indicates low rigidity and inability to keep its shape. However, there is no direct dependence of thermal conductivity and stiffness on density. The length, thickness of the fibers, as well as the type of their orientation are of decisive importance.

Mineral wool in the form of plates is convenient for insulating the attic alone

We compared the actual parameters of mineral wool grades recommended by leading manufacturers for roof insulation. Only three names satisfy all four declared requirements: Rockmin and Rockmin plus (Rockwool brand), as well as Rocklight TechnoNIKOL boards. Plates of these brands (format 1000 × 600 mm and 1200 × 600 mm) with a thickness of 100 mm weigh 1.6 kg, respectively; 2.1 kg and 2.9 kg. At the same time, they are elastic and hold their shape well.

There are many types of mineral wool insulation that are superior to those recommended by us in terms of thermal resistance or stiffness. But they are all ill-formed, either very heavy or not resilient enough, and therefore inconvenient to work alone.

The composition of the roofing cake

Insulation of a residential attic with mineral wool requires mandatory compensation weaknesses of this material: the ability to absorb moisture coming from the room, as well as high blowability and low resistance to atmospheric precipitation. Therefore, two, and sometimes three membranes are introduced into the composition of the roofing cake, provided that fibrous insulation is used. In the direction from the room to the outside, the layers are arranged in the following order:

Scheme of attic insulation with mineral wool

1. Ceiling finish. The warmest material for this layer is drywall and a layer of putty (taken into account separately in the thermal calculation).
2. Air gap formed by the crate for fixing the finishing cladding. Equal to the thickness of the laths (or galvanized profiles) of the crate. This gap is not necessary for the operation of the heat-insulating system.
3. Vapor barrier film. Protects the insulation from the ingress of steam rising from the room.
4. The main insulation (2 - 3 layers of mineral wool).
5. High diffusion membrane (waterproofing). Its peculiarity lies in the one-way passage of water. Moisture coming from below (evaporated by mineral wool) should freely penetrate through the membrane, and water entering from above (precipitation and condensate) should drain under the roofing down to the street. Films of this type combine the functions of a hydro-barrier and wind protection. In domestic practice, isospan three-layer membranes have proven themselves well. It is better to use Izospan AQ proff for the attic, which is characterized by high strength and a good steam transmission rate (1000 g / m2 per day). The gap between isospan and mineral wool is not needed.
6. Ventilation gap between the membrane and the roof deck. It is formed by battens of lathing, located perpendicular to the rafters in the plan. The thickness of the crate is usually 4 - 6 cm.
7. Roof decking.

Sufficient insulation thickness

To determine the required thickness of mineral wool, one of the independent online thermal calculators (not owned by any manufacturer of insulating materials) should be selected. In the filters, you must specify the region and all the components of the roofing pie, indicating the materials and thicknesses. Each air gap is also a significant insulating layer.

The thickness of the attic insulation must be accurately calculated

After that, the calculation will show the final temperature inside the room. Using the method of successive approximations, you can find the value of all thermal insulation parameters that provide the necessary level of comfort in the attic.

In most regions of the European part of the Russian Federation, the required thickness of mineral wool at internal insulation attic is 280 - 300 mm.

Often, developers are content with values ​​​​of 200 - 250 mm, for the reason that "this corresponds to the geometry of the rafters" and "this is proven by practice." They simply ignore the fact of compensation for heat in the attic due to heating systems located on the first floor. The money saved on attic insulation translates into significant annual energy overruns.

Table: comparative characteristics of various heaters and the required thickness depending on thermal conductivity

Mineral wool self-assembly technology

First you need to make sure that the outer elements of the roofing cake (or at least the waterproofing layer) have already been installed. This is necessary to protect the mineral wool from atmospheric moisture before installing the outer membrane.

Mineral wool is tightly laid between floor beams or racks

Next, the width of the openings between the rafters is checked. If the size fluctuates between 550 mm and 600 mm, then you will not have to cut the insulation (you can use the factory width of the plates 600 - 610 mm). If the distance between the rafters is more than 600 mm, it will be necessary to cut out fragments of the required width from the mineral wool slabs based on the assembly compression of 20-30 mm. For example, if the rafter niche has a width of 720 mm, then sections of 700 × 600 mm are cut out of 1200 × 600 mm slabs. The remains of 500 × 600 are accumulated for use in the insulation of various contours (for attic walls, around window openings, for laying crossbars on top, etc.)

The second method consists in diagonal cutting of rectangular plates and the relative displacement of the halves along this diagonal. When offset, the overall width increases, ensuring that the ends of the wool rest against the vertical edges of the rafters. However, in this case, for a tight joint, the following plates will have to be cut curved from the outside.

Installation of mineral wool and further operations are carried out alone using the following methods:

Fixing mineral wool with nylon thread

1. If there are no significant differences in width in the openings between the rafters, mineral wool boards can be installed without preparatory work. Pressing the material by 20 - 30 mm allows you to lay out all the elements of insulation from the inside of the room into the roof slope. Otherwise, to support the wool, a temporary (removable) crate is used from planks, boards, or a nylon thread (non-removable), stretched along the lower edges of the rafters in a zigzag using a stapler. Layers of mineral wool are laid out in a checkerboard pattern to overlap the joints.
2. From below, a vapor barrier film is attached to the ends of the rafters with a stapler. It must be joined with an overlap, gluing the joints with special adhesive tape.
3. A crate is mounted to install the finishing ceiling cladding.

Video: how to insulate the roof of the attic floor with mineral wool (Isover Profi 100 mm and Ursa Pure One 50mm)

The total thickness of the insulation was 250 mm. The fixation of the insulation is carried out using a bar 50 × 40mm. To eliminate the sagging of mineral wool, the author of the video additionally uses twine, which is fastened with a stapler to the bar.

Mauerlat and wall insulation

The insulation of the attic walls should form a closed circuit with the insulation of the roof slopes. Thermal calculation for walls is carried out separately. In most cases, it shows the required insulation thickness 1.5 times less than for the roof.

Mauerlat is a log or beam that serves to transfer and average pressure from the rafters to the upper end of the wall. Mauerlat insulation is recommended to be carried out before the installation of the hydrobarrier. Mauerlat is isolated from above and from the side of the street. Then the membrane is installed.

Video to help: why moisture forms on the roof of the attic, insulated with mineral wool

Conclusion

In addition to the high functional properties of mineral wool used in residential roofing, consumers are attracted by the possibility of significant savings. The main source of this is not the price of the material, but the independent performance of work. However, for solo installation, a number of additional requirements are imposed on the fibrous insulation material. Only taking them into account when choosing a brand of cotton guarantees you a calm, measured work.

If the attic remains non-residential, the air in the under-roof space serves as good thermal insulation (along with floor insulation). In the case of the attic, everything is completely different: here the thermal insulation is very close to the roofing material and the task is not only to insulate the attic, but also to create conditions for the entire roofing system to serve for a long time.

Let's say right away that all the wood that is used in the construction of the roof must be treated with antiseptics. Indeed, everything: both battens and counter-battens, and rafters. All wooden details. It is also necessary to make them less flammable. To do this, they are treated with flame retardants. All elements that are located on the side of the street are treated with compounds for outdoor work. Treat all wooden parts facing the inside of the room with impregnations for interior work. If you use the composition for outdoor use indoors, the specific smell will remain for several years. If on the contrary, the wood outside may suffer: the degree of protection is insufficient. So don't skimp on this.

More. Before describing how to insulate a mansard roof with your own hands, it is worth recalling this: a ventilation system must be organized in the under-roof space. To do this, special arrangements are made on the skate. ventilation holes. Through them, the air from under the roofing material escapes, carrying away excess moisture. And it must fall under the roofing through the overhangs. There absolutely can not be done all hermetically. That's where the air comes from. Only in this way will the condensate dry out in a timely manner and the roof will serve for a long time.

Proper attic insulation

To keep the attic floor warm in winter and cool in summer, there were no problems with high humidity, icicles did not freeze on the roof, it is necessary to properly insulate the roof. But in the case of a roof, insulation, vapor and waterproofing are a complex solution, and one without the other works very poorly, or does not work at all.

If the sloping roof is at the same time the walls of the attic floor, the pie will be as follows (from inside to outside):

• internal lining (drywall or lining);
• crate;
• vapor barrier;
• insulation (the thickness of the insulation depends on the region and the parameters of the insulation, for central Russia it is about 200 mm);
• superdiffusion membrane;
• ventilation gap;
• crate;
• roofing.

The photo shows the insulation of a broken mansard roof in a graphical version. Please note: a superdiffusion membrane is laid over the insulation (marked blue color). Its purpose is to prevent condensate formed or precipitation seeping through the roofing from entering the insulation and removing the steam that nevertheless got into the mineral wool, ensuring its drying. Therefore, with a vapor permeability of 1500 g / m 2. This layer is often called waterproofing (as it is, in fact, it is), only waterproofing is vapor-permeable.

Laying waterproofing

Ideally, it fits exactly as shown in the figure: wrapping the rafters and closely fitting on the insulation. Often, to save money, they roll it out over the rafters, but without pulling it, but making it sag by 3-5 cm. This option also works well: moisture gets on the surface, and then rolls down and out of the roof. Here is another one important point: The membrane must extend into the gutter. Then the moisture will be removed from the under-roof space.

A few more points on laying the membrane. It rolls across the rafters, starting from the bottom. The first row is launched into the gutter. The next one is rolled out with an overlap of 10-15 cm. And so on until the ridge. On the ridge, the membranes are cut off on both sides along the upper edge and fixed. A strip rolls along the ridge, descending from one and the other side of the roof. It turns out a coating through which water flows down to the gutter itself.

Vapor barrier and rules for its installation

It is worth talking separately about the vapor barrier. It must also be a membrane. Polyethylene or polypropylene film will not work: its characteristics are not the same. The vapor permeability of this layer (expressed in g/m2) should be as low as possible. Ideally, it is equal to zero. That is, this layer should not allow vapors to pass from the room into the insulation layer. When using mineral wool as insulation, this is very important: when wet, it loses more than half of its properties, and when it freezes in a wet state and then melts, it generally crumbles into dust.

Therefore, the vapor barrier film is also laid with the entry of one panel onto another. Moreover, these joints are glued with a special double-sided vapor-tight tape (it looks like sticky rubber). Ordinary painting or stationery will not work. They do not provide 100% vapor protection. In addition to the joints, all junctions are also glued: from below, from the sides, from above.

A line is drawn on the vapor barrier. It marks the border from which the next layer starts (this is the amount of overlap) and the line along which the canvases are fastened with adhesive tape

The vapor barrier is usually attached to the lags with stapler brackets or, as in the figure, with planks of the inner crate for mounting the skin. In this case, another ventilation gap is formed, which will dry the finish and the membrane. This clearance is desirable but not required. In principle, the lining can be mounted directly on top of the membrane.

thermal insulation

The better to insulate a sloping roof - the question is complex and there is no unequivocal answer to it. Mineral wool is used, only hard, with a density of 30-50 kg / m 3. Since the mansard roof usually has a large angle of inclination, soft materials can slip. It is for this reason that it is better to take plates. Although in this case it will be necessary to adjust the pitch of the rafters to the dimensions of the insulation: it should be 10-15 mm less than the width of the plate so that the material becomes “spread” between the beams and holds well.

It is necessary to lay thermal insulation in such a way that there are as few cold bridges as possible. For central Russia, usually 200-250 mm of mineral wool is required. These are several layers of mats. When laying between the rafters, the slabs are positioned so that the seams of one row overlap the next. The width of the insulation, as already mentioned, should be slightly wider than the distance between the rafters. Then the plate becomes dense, excluding the presence of cracks. If the width is more/less, you have to cut the material. At the same time, the chance to get a smooth edge is small and there are many residues.

If the dimensions of the rafter do not allow laying the entire insulation, planks of the required thickness are stuffed across from the side of the room. Between them lay the remnants of insulation. From above, a vapor barrier is already attached to it and, if necessary, a crate for finishing. This option is even better: cold bridges are completely excluded, blocking even the rafters. This method requires a little more installation costs, but it will definitely be warmer in the attic, which will reduce heating costs.

How to insulate a mansard roof: the order of work

The device of the attic floor is good because it allows you to stretch the end of construction. It is immediately necessary to lay and fix the superdiffusion membrane on the rafters, the crate and roofing material on it. And attic insulation can be done from the inside after a while.

But pay attention: the waterproofing layer must be mounted together with the roofing. This is the main mistake of many developers: they do not lay this membrane. As a result, either it is necessary to remove the roof and lay it, or to invent systems to correct this shortcoming. The whole problem is that in this case there is no cheap solution that guarantees the normal state of the materials.

We warm outside

If you do everything at once, the order of work is as follows:

With this option, it is not difficult to work with a heater: it is easy to lay it, it relies on a crate (laces).

Warming from the inside

This option allows you to move the interior decoration for the required period (useful if there is a shortage of funds). After installing the truss system, here's what you need to do:

• roll out and fix the waterproofing;
• stuff the crate (if necessary, a counter-crate);
• install roofing material.

For the first stage, this is all the necessary work. After the opportunity to continue, you will need to insulate the mansard roof from the inside. It will no longer be so convenient to work: you will have to make a building envelope that will not allow you to push the insulation higher than necessary. The cotton wool itself will have to be fixed in some way: it strives to fall on the head. The order of work is as follows:

A few notes on how you can lay the heat-insulating material. If these are high-density mineral wool mats and their width is a little more than the step between the joists, everything is relatively simple: they themselves hold up well.

If rolled mineral wool is laid, everything is more difficult. Making the insulation of the mansard roof from the inside, it is laid from the bottom up. Take a string, a construction stapler. Roll out the cotton, press it against the planks, fasten a piece of lace with staples, drawing the letter Z. This is how you fix the first layer, followed by the second and all subsequent ones.

In general, if you want the mansard roof to be warm, it is better to use mineral wool mats of the required density of 30-50 kg / m 3. They are tough enough to hold their shape well. Softer rolled materials on vertical surfaces or with a large slope are caked, settling down, the thermal insulation of the mansard roof deteriorates.

What is the best way to insulate a mansard roof

As mentioned above, the most popular material for insulating a mansard roof is mineral wool. It is good, but not at all ideal: it is afraid of moisture. That is why it requires such careful protection from all sides so that it retains its properties.

Styrofoam (expanded polystyrene)

Sheathe the roof with polystyrene foam or extruded polystyrene foam - EPS. Polyfoam (grades PSB-S-25, PSB-S-35) has good characteristics, but when burned, it emits harmful substances, although there are self-extinguishing grades (with special additives). Here they are better for roof insulation for roof insulation.

The main advantage of polyfoam: low price. It is mounted simply: it is placed between the rafters, all joints are sealed with mounting foam. It is convenient to insulate the attic from the inside with foam plastic: order the plates of the right size - 10-15 mm more than the gap between the rafters - and put them tightly. Due to the elasticity, they hold very well.

From the side of the roof, a ventilation gap is also left and waterproofing is laid. But she is more protective. wooden structure, since polystyrene foam is not afraid of moisture, it practically does not absorb it itself, it does not conduct steam. This is where the main drawback lies. Since the material does not let the vapor through, a good ventilation system is needed in the attic, and this is an additional cost.

XPS has the best characteristics: under equal conditions, its thickness is two times less than mineral wool of the specified density and one and a half times less than that of polystyrene. It also has a system of locks, which reduces the risk of cracks, through which heat will fly away. Another plus: mice and insects do not like extruded polystyrene foam, fungi and mold do not multiply on it. What limits its use: a solid price. You also need a ventilation system.

EPPS brands - Extrol, STEREKS, PENOPLEX, URSA XPS, Technoplex, PRIMAPLEX (PRIMAPLEX), Styrofoam (Styrofoam), KINPLAST (KINPLAST), Teploizolit, GREENPLEX (GREENPLEX). While the technology is the same, there are some differences in performance, so compare when choosing.

Not so long ago, a new type of insulation appeared: expanded polystyrene foam. It is applied in liquid form to the surface, reacting with air, increases in size many times, filling all the cracks and forming a monolithic layer. This is perhaps the only way today to correct the situation and insulate the attic with high quality, if during the installation of the roofing they forgot to lay a layer of waterproofing.

Ecowool

This insulation has good characteristics (thermal conductivity coefficient 0.036-0.040 W / m² ° C), but a special application technology. It is necessary to organize a closed cavity into which the composition is poured. In case of mansard roof the side parts are rafters, sheet material (fiberboard, GVL, plywood, etc.) is nailed to them from below and from above.

A feeding sleeve is launched into the formed cavity, from which loosened cotton wool comes out under pressure. It fills all the cavities, forming a single layer of insulation.

The main advantage of ecowool compared to all the heaters described above is that it conducts steam. It can absorb moisture up to 20% of the volume, and then give it away. That is, there is no need to organize a vapor barrier: humidity is regulated in a natural way, as is the case with wood. The ventilation gap between the roof and the insulation should be all the same, as well as the properly organized movement of air masses in it.

Improving the performance properties of the roofing cake and achieving living comfort can be ensured by high-quality thermal insulation. The event is relevant if the attic floor is used for living or recreation. When planning the insulation of the mansard roof from the inside, pay attention to the need for work, the choice of thermal insulation materials, and carefully study the technological algorithm.

The need for warming measures

Thermal insulation of the attic floor is required due to its location next to the flooring surface. Exceeding the ventilation gaps by 15 cm leads to cooling of the room, and it becomes uninhabitable. Experts identify several reasons why the attic roof should be insulated from the inside:

• protection from the effects of weather factors;
• reduction of up to 20% of heat losses;
• reduction of overheating;
• regulation of air humidity and reduction of the likelihood of condensation;
• the possibility of performing combined insulation.

It is also necessary to create a heat-insulating coating to prevent incandescence in summer time. The work is carried out using insulating materials, which must be selected in accordance with regulatory requirements.

How not to make a mistake when buying a heater?

The norms of thermal insulation to which the roof is subject and attic room, are specified in SNiP 2.3.79-1998. The same document recommends how to choose insulation for the attic roof. quality material features:

• low thermal conductivity, due to which a comfortable microclimate is maintained on the floor;
• moisture resistance to prevent internal and external leakage. If the selected material is hygroscopic, waterproofing is laid;
• small mass, facilitating pressure on the surface. On the top floor, it is appropriate to work with mineral wool fabrics (density 45–50 kg/m3) or fiberglass (density 14 kg/m3);
• compliance with the parameters of fire safety, durability, resistance to sudden climatic changes;
• the ability to maintain shape when located at a non-standard angle. Otherwise, the fabric slips, and the quality of the insulation of the structure decreases;
• optimal thickness for the climate in the region of residence. Products with good density and small thickness will be universal;
• environmental safety and long service life.

On the modern market there are a lot of materials with positive and negative characteristics. Each type of thermal insulation coating differs in the method of installation, therefore, it is possible to determine which insulation for a mansard roof is better only by studying its features.

Varieties of thermal insulation materials

When planning how you will insulate the roof of the attic floor from the inside, it is important to choose the right heat-insulating layer. In construction, mineral wool, polyurethane, expanded polystyrene and ecowool are actively used.

Features of mineral wool materials

Mineral wool is a thin fiber based on glass or basalt. The insulation well blocks steam, condensate, retains moisture, and does not ignite. A small mass, combined with environmental friendliness and a high coefficient of thermal conductivity, justify the use of mineral wool in private homes.
When buying mineral-based cotton wool, be guided by its type:

• Fiberglass can cause itching and irritation if it comes into contact with bare skin. The material is used only on an inclined surface;
• basalt fibers do not ignite even at a temperature of 1000⁰С. But the chaotic arrangement of the villi makes basalt wool hard, so it is produced in the form of slabs.

In order to qualitatively insulate the roof of the upper floors, you need a material with a density index of 25. Mineral wool must be laid between the rafter frame with a layer of 15-25 cm, depending on the climate of your region.

Durable Styrofoam

Expanded polystyrene boards can be selected to provide thermal insulation for wall and roof surfaces. The material is placed between truss system and under it. Manufacturers offer two options for expanded polystyrene:

• tile foam with a granular structure. White slabs have dimensions of 0.5x1 and 1x1 m;
• penoplex (polystyrene with extrusion), which is homogeneous.

Foam-based polystyrene is an excellent raw material in terms of price and thermal insulation characteristics. However, durable material has a high cost and requires additional finishing drywall sheets or clapboard. When using material for an attic roof from the inside, there are risks of fire, release of toxins and the formation of gaps if wooden frame gives shrinkage.

Polyurethane foam application technique

Thinking about how to insulate the floor under the roof, pay attention to liquid materials- polyurethane in the form of a foamed mixture. Mounting foam applied from a special container in a dense layer. The use of foamed polyurethane eliminates seams. On large areas, high-tech installations are used, which only specialists can operate.

Ecowool - technical specifications

Ecowool is made from cellulose waste, it is a dense loose cotton wool. Material - the best insulation due to its environmental friendliness and loose structure. Safety for human health, gap closure density and moisture resistance ensure the ease of use of cellulose wool for the roof of the attic floor:

1. Backfilling material in dry form on horizontal surfaces in the presence of ceiling beams.
2. Application of a thick wet composition. Ecowool is mixed with an adhesive, and the resulting mass is applied to the frame with a spatula.
3. Warming by backfilling inside the roofing cake.

Cellulose cotton fractions have the ability to pass air, maintain normal temperature regime even in hot weather. The sorption qualities of the insulation provide high-quality absorption of excess condensate, therefore, thinking about the best way to insulate a mansard roof, stop at ecowool.
When insulating the roof of your attic, do the work in a comprehensive manner - start with the purchase of material, planning events, laying hydro or vapor barrier.

Preparing for attic insulation

To understand the process of creating a heat-insulating coating on the top floor own house, it is important to imagine a roofing cake. It consists of a material on the roof surface, a waterproofing layer, lathing, insulation, cornice strips, vapor barrier and rafters. When thinking about how to insulate a mansard roof, follow the sequence of work.

Laying waterproofing

Sheets of roofing felt or PVC film are wrapped around the rafters with a sagging of 3-5 cm. Thanks to this technique, moisture rolls off the roof onto a special gutter. Membrane waterproofing provides complete tightness of the structure. It is laid like this:

1. The material is rolled out perpendicular to the truss frame, starting from the bottom.
2. The first row is led into the gutter.
3. The second row is rolled out, observing an overlap of 10-15 cm.
4. On the ridge, the membrane is cut and fixed.

When working, consider the direction of the moisture-blocking layer: one side is led to the roof covering, and the second - to the insulation material.

We form a vapor barrier

For optimum steam protection, a special foil membrane is required. The algorithm for its flooring is somewhat reminiscent of the previous one:

1. The material is rolled out, observing the overlap of the panels.
2. The joints must be glued with adhesive tape (in the side, upper and lower parts);
3. A stapler is used to fix the membrane film to the lags.

A crate of wooden lining is laid on top of the vapor barrier.

Phased thermal insulation of the attic

How to properly insulate a mansard roof yourself? Start activities some time after arranging the crate! Tasks are performed externally or internally, the use of which is determined by the degree of readiness of the object.

External method of thermal insulation

If you're building your home, then don't ignore building a heat shield in the attic. When insulating the roof of the attic at home with your own hands, follow the step-by-step algorithm of work from the inside:

1. Fill the crate across the truss frame or fasten a strong galvanized wire.
2. From the side of the roof, lay the heat-insulating material, choosing it according to the climatic conditions of the area. Try to match the seams so that cold air does not penetrate through the gaps.
3. Roll out the waterproofing membrane and stuff the crate.
4. Glue a layer of internal vapor barrier.
5. Perform roofing.

The external method provides ease of laying the insulation on the formed crate wire.

Internal insulation

To insulate the attic roof correctly with your own hands, working from the inside, first install the rafters, on top of which lay the waterproofing, the crate and the roofing material. Adhere to the construction technology:

1. Make a barrier to prevent material from entering above the acceptable level.
2. Consider a way to fix ecowool or mineral wool.
3. Stuff the planks between wooden lags, adhering to a step of 40-50 cm to create a ventilation gap.
4. Place the thermal insulation, matching the seams with an overlap.
5. Nail the crate frame - it will hold the insulation layer.
6. Glue the membrane that isolates the room from steam.
7. Mount the crate.
8. Finish the room.

It is worth laying layers of mineral wool with a width slightly larger than the step between the lags. roll material roll out, starting from the bottom. Rise up gradually, fixing the insulation with a stapler crosswise.

How to finish a warm attic floor?

Having warmed the attic, proceed to it interior decoration. You can mask the insulating material and create a surface for further decoration with drywall, GVL, glass-magnesium sheet or clapboard. The last option is successful if you plan to use the attic for living.
Having decorated the wood trim, treat it with fire and anti-rot agents. If you prefer GKL or LSU, screw the sheets, and then go through the places of the seams with a putty mixture or mastic.
Having learned how the attic roof is insulated, you will not only create comfortable conditions for being in the room from the inside, but also reduce costs during the heating season. Insulation, applied not in one, but in several layers, will ensure maximum heat retention in country house even in harsh domestic climates.