Insulation of the attic floor with an unheated attic. We insulate the ceiling of a cold attic. Requirements for the construction of a pie.

There are two types of attic space - cold attic and a combined attic or attic. In a cold attic, insulation is laid horizontally across the attic floor, and the temperature inside the cold attic is about the same as outside.

The temperature inside a cold attic should not exceed 4 °C outside air temperature (rules and regulations technical operation housing stock, resolution of September 27, 2003 No. 170, clause 3.3.2), i.e. if the temperature outside is -15 °C, then in the attic it should be no more than -11 °C. If this difference is greater, then, for example, at an outside temperature of -5 ° C, the slope will heat up, the snow on the roof will melt and flow onto the eaves. The cornice will not heat up, because... there is no warm room underneath, and the water on it will turn into ice, forming icicles. How more ice will form on the eaves, the greater the chance of leakage, the higher the load on the roof and the higher the risk of ice breaking, which can lead to tragic consequences. All this reduces the service life of both the roofing covering and the roof as a whole.

Rice. 1 Ventilation of a cold attic.

To ensure normal temperature conditions in a cold attic, it is necessary, first of all, to insulate the floor between the attic and the living space. The thickness of the insulation is calculated based on several parameters, the main one of which is the location of the house. The second most important criterion for maintaining the temperature regime of the attic space is under-roof ventilation.

In addition to insulation and ventilation, the temperature regime of the attic space is affected by: uninsulated hatch covers for access to the attic, ventilation pipes for rooms (kitchen, bathroom) leading into the attic space, uninsulated hot water supply located in the attic, etc.

The roofing pie for a cold attic can be divided into two parts. The first part is along the floor between the attic and the living space. The second part is along the slope.

The first part of the roofing pie, depending on the type of ceiling, looks like this:

Rice. 2 Pie on the concrete floor.

Rice. 3 Pie on a wooden floor.

The vapor barrier serves to prevent moisture from entering the room into the insulation. On a concrete base, it is best to use bitumen roll material with fused overlaps. A film vapor barrier is used along the joists with the obligatory gluing of the overlaps with sealing tapes. As a vapor barrier, it is necessary to use vapor barrier films D-Folie B, D-Folie B 90 or D-Folie BR.

The insulation is laid in several layers with joints spaced apart to eliminate cold bridges.

The hydro-windproof membrane protects against heat loss and moisture ingress. Moisture can form due to condensation, snow blown into the attic space, and also due to possible leaks. Superdiffusion membranes D-Folie A 150 or D-Folie A 100 must be used as hydrowind protection.

In any case, regardless of the type of ceiling, it is not recommended to cover the insulation on top entirely with plywood or boards. If you occasionally need to walk through the attic space, it is better to provide paths from boards without covering all the insulation.

The second part of the roofing pie using flexible tiles in a cold attic looks like this:

Rice. 4 Roofing pie for a cold attic.

When insulating a house, you must definitely pay attention to the laws of physics. According to them, the air heated in the rooms will rise to the ceiling. If the attic is not insulated enough, the heat will escape outside, and this whole process can be called heat loss.

In order not to heat the street and retain more heat in the house, it is necessary to insulate the ceiling. If you still don’t know whether it’s worth doing this work, then you should take into account that 25 to 40% goes through the roof. This data is especially relevant for houses with cold roofs.

Thermal insulation of the ceiling will perform three functions at once, which are necessary to create a comfortable microclimate. The material will soundproof, which will keep the house quiet during wind and rain. In winter, insulation will eliminate heat loss and through which heated air can freely escape outside. Thermal insulation is also needed in the summer heat, because with its help you can create a barrier against heated air. Even at the most hot weather the inside of the house will remain cool.

Material selection

If you are planning to insulate the ceiling of a cold attic, then you need to understand the variety of materials. The insulation option you choose should be able to withstand a wide range of temperatures ranging from -30 to +30 °C. It should not freeze at low temperatures and release harmful substances when heated. It is important to purchase fire-resistant thermal insulation. This is true for electrical wiring.

It is better if the insulation is moisture resistant so that it does not lose its properties when wet. It should not cake quickly in order to fulfill its purpose for as long as possible. Insulation of the ceiling of a cold attic can be carried out using rolls, slabs or this is true for a floor made of wooden beams. Whereas if you have to work with concrete slabs, then you should purchase bulk or slab materials.

Today the following are produced as mats and slabs:

Styrofoam;
seaweed;
mineral wool;
extruded polystyrene foam;
straw.

As for roll insulation, they are offered for sale in the following varieties:

stone wool;
mineral wool;
glass wool;
algae ladders.

When choosing bulk materials for insulating the ceiling of a cold attic, you may prefer:

expanded clay;
reed;
straw;
buckwheat tyrsa;
ecowool;
sawdust;
slag;
foam granules.

Features of insulation with mineral wool

Using basalt wool

Basalt insulation is made from gabbro-basalt rocks and acts as optimal option for thermal insulation of the ceiling from the attic. The fibers of this material are more flexible and therefore not so brittle. They are well compressed into mats that have sufficient strength.

When deciding to insulate the ceiling of a cold attic with basalt wool, you have at your disposal a material that copes well with the impact external factors, therefore it can be laid on the side of an unheated room. Insulation is sold in slabs or rolls, which can have different densities. Sometimes there is a foil layer on one side, which can enhance the insulating effect, because the heat will be reflected into the room.

About the dangers of mineral wool

All mineral wools have one general disadvantage, which is expressed in binder, consisting of phenol-formaldehyde resins. During operation, they are constantly released into the air, which can be hazardous to human health. Therefore, this thermal insulation cannot be considered completely environmentally safe. Basalt wool is laid according to the same principle as mineral wool.

Use of extruded polystyrene foam

Expanded polystyrene, also called polystyrene foam, is not a very dense material. It can be used when the floor is made of beams and joists. Extruded polystyrene foam is stronger and denser than regular foam. Before laying it, the surface is leveled.

There is no need to lay a vapor barrier on the warm side of the floor, because concrete slabs have almost no vapor permeability. Insulating the concrete floor of a cold attic involves laying a vapor barrier film. The next layer is insulation boards, which are arranged in a checkerboard pattern. The joints are filled polyurethane foam. As soon as it dries and hardens, the canvases are poured concrete mortar thickness within 6 cm. After the screed has dried, it can be used as a floor. Flooring can be laid on the surface.

Using penoplex

If you insulate the attic, this will not only increase the service life of the rafter system, but also the roofing, and will also increase the level of thermal protection of living spaces under the attic. Insulating the ceiling of a cold attic with penoplex has replaced other technologies that were used quite widely in construction. In this case we are talking about the use of glass wool, expanded clay and sea grass.

Modern choice - “Penoplex panel”

In rural areas, the floor of an unheated attic is still insulated with clay and wood shavings. Today we offer for sale the Penoplex panel, which is specially designed for cold attics. If you neglect the work on thermal insulation of the room above the living space, this may cause the insulation to get wet, which occurs due to condensation. Sometimes, under appropriate conditions, the roof structure begins to collapse altogether, which is especially important when there is constant dampness.

Should I use metal fasteners?

When the attic floor is not insulated, icicles and frost constantly form. Large heat losses were mentioned above; they are caused by a weak level of thermal protection. When developing a scheme for insulating the ceiling of a cold attic using penoplex, you must take into account the features of how the ceiling units will be connected to the thermal insulation. The manufacturer does not recommend the use of metal fasteners, because they contribute to the formation of cold bridges, which reduces the level of thermal protection.

To create a heat-insulating cake, a leveling screed is laid on the floors. Next, a vapor barrier in the form of polyethylene is laid. The next layer will be penoplex. We should not forget about the presence of a separating layer in the form of polyethylene. On last stage a cement-sand screed is poured.

Insulating the ceiling of a cold attic may involve working with sheet material in the form of plywood or OSB. In this case, a vapor barrier, wooden beams and penoplex insulation are laid on the surface. You can cover it with sheet material in the form of gypsum fiber board or fiber board.

Finally

Insulating a cold attic allows you to create a boundary between cold and heat. Due to the formation of condensation in the attic floor area, appropriate conditions arise that can contribute to significant heat loss. Proper insulation of the floor allows you to create a barrier with a low degree of thermal conductivity.

In modern construction of rafter roofs, the very concept of a roof - the upper outer part of the structure - has been replaced by roofing pie– alternation of several layers of materials, each of which performs a specific function.

The sequence and technology of laying the roofing pie depends on the characteristics of the top covering (for example, metal tiles) and the specifics of the room located under the roof: whether it will be a cold attic or a warm attic.

Depending on whether it is warm or unheated room plan to install under the roof, the sequence of laying materials and the number of elements in the roofing pie will be different.

Cold attic without insulation

The waterproofing film or membrane is laid from bottom to top directly on the rafters. It is secured to them with counter-lattice bars. The thickness of the bars is at least 2 cm - to ensure a ventilated space between the film and finishing coat. Sheathing boards are mounted perpendicular to the counter-lattice bars, to which sheets of metal tiles are attached.

Between waterproofing film and metal tiles, it is necessary to install a ventilation gap that is equal to the thickness of the counter-lattice bar. Failure to comply with this point will lead to premature corrosion of the metal and a decrease in the service life of the coating.

Insulated attic

Unlike the cold version, the number of layers in the attic roof increases due to vapor barrier and insulation. The peculiarity of such a cake is in the correct adherence to the technology of laying materials - their sequence and provision of ventilated gaps between them.

vapor barrier;
rafters;
insulation above the vapor barrier between the rafters;
waterproofing;
counter-lattice;
sheathing;
metal tiles.

Installation sequence

The vapor barrier film is attached to the rafters with an overlap of at least 10 mm. It is important to ensure tight connections between the seams and the places where the film adheres to the roof elements. If the manufacturer provides for the presence of a smooth and rough side in the material, then the smooth surface is laid against the insulation.

The insulation - most often basalt mineral wool or a fiberglass-based product - is installed above the vapor barrier. Mineral wool fits tightly between the rafters if it is cut 1–2 cm wider than the distance between the rafters.

A sufficient layer height is 150 or 200 mm. Depending on the thickness of the material (it can be 50, 100, 150 mm), it is laid in several layers, so that the first layer overlaps the joints of the second. This helps to avoid the occurrence of “cold bridges”.

Diffusion membranes can be laid directly on the insulation, while waterproofing films require an air gap (at least 3 cm). It ensures air movement and drying of mineral wool from moisture, which partially penetrates through imperfect seams of the vapor barrier.

Counter-lattice bars are installed above the waterproofing film; they will provide an air corridor (4–5 cm) between the film and the metal tile.

When the temperature changes (for example, it’s hot during the day and cold at night), condensation forms on the inside of the metal tile, which flows down through the waterproofing film without getting on the insulation. A ventilated space is required for this moisture to dry completely. Read more in this article.

The sheathing is attached to the counter-lattice: the distance between the boards is 350 mm equal to the wavelength of the metal tile, the installation of which completes the entire roofing pie.

The roof must reliably protect the house from water, wind, temperature changes and, in fact, is the fifth wall, the design of which is a little more complex than the others.

Failure to comply with technology, errors in construction and alterations result in unnecessary waste of time, money and health, which is why it is so important to have a correct understanding of the features of roofing structures.

Roof installation with a cold attic

Majority pitched roofs in our country they have a cold attic in their design. This name is due to the air temperature in the attic, which should not differ much from the air temperature outside the house. With this arrangement of the attic space, a sufficiently large buffer air zone is formed, which allows you to effectively regulate the temperature in the attic if it is properly arranged.

Cold attic design

When building the roof of a house, many people think about making a cold attic or attic underneath it? The easiest way to organize a roof is with a cold attic space. Construction of an attic will cost several times more and require more labor.. Although, it is undeniable that the attic will significantly expand the living space.

Cold attic roofs have the following main components in their pie::

roofing;
attic external walls (applicable for gable roofs with pediments);
insulated ceiling between the living space and the attic.

Ventilation is provided by eaves and ridge vents. The air passing through the eaves openings is called supply air, and the air leaving through the ridge is called exhaust air. Additionally, ventilation can be done through dormer windows on gables or roof slopes. The windows are equipped with louvered grilles to allow the ventilation intensity to be adjusted.

Dormer windows are located on opposite slopes of the roof so that there are no unventilated areas.

Dormer windows can be rectangular, triangular and semicircular in shape. Their lower part should be at a height of no more than 0.8-1.0 m from the floor of the attic, and the upper part should not be lower than 1.75 m from the floor in the attic. They can also serve as an exit to the roof of the house to inspect the roof, ventilation and chimney elements.

Steam and thermal insulation of a cold attic

For a roof with a cold attic, it is most important to minimize heat loss through the attic floor. For both wooden and reinforced concrete floors, a vapor barrier is mandatory. It is laid on the ceiling itself and protects the insulation from vapors that can condense in the heat insulator after passing through the ceiling of the living room. Slab and bulk materials can be used as insulation. The ceiling pie consists of a vapor barrier, floor beams and insulation.

Often used in ceiling coverings the following types heat insulators:

expanded polystyrene and foam boards;
mineral wool slabs or mats;
expanded clay granules;
fuel or granulated slag;
sawdust with lime or clay;
pumice.

The thickness of the required insulation layer is selected depending on the estimated winter temperature using the table below.

Winter temperatures are calculated according to SNiP 2.01.01-82 (building climatology and geophysics) or selected by regions of the Russian Federation from the corresponding climate maps.

The insulation is laid between the joists or ceiling beams, and a boardwalk is made on top for the attic passages. Joists are usually 50 mm thick, and decking boards are 25-35 mm thick.

For ventilated attic spaces, soft or semi-solid heat-insulating materials are considered the most optimal.

Attic waterproofing device

Waterproofing roofs with a cold attic, according to many experts, is a controversial issue. Some say that waterproofing must be present under the roofing material, while others categorically recommend that it be abandoned. Here, a lot depends on the type of roofing material and the angle of inclination of the roof slopes.

Metal roofs are most susceptible to corrosion, which occurs due to possible small leaks or condensation. Therefore, we once again draw your attention to the fact that ventilation plays one of the main roles in the fight against condensation formed.

For gently sloping metal roofs Experts recommend installing superdiffusion membranes. It will prevent moisture from entering the outside of the roof when snow or rain blows in. No matter how well the roof is laid, there is always the possibility of minimal leaks. That is why, by paying a little extra, you will receive additional protection from moisture getting on the insulation in the ceiling of a cold attic.

Possible leaks or condensation entering hydrophobic insulation materials significantly reduce their thermal insulation properties.

If, for example, slate is used as a roofing material, then waterproofing can be abandoned. There is also corrugated sheeting with an anti-condensation coating on the market, which can hold up to 1 liter of water per 1 m2. For our part, we recommend always using waterproofing membranes, because this is the cheapest and easiest additional method protect your roof from possible leaks.

When installing waterproofing membranes, a counter-lattice is used. It serves as a fixing strip and, due to its height, provides the necessary clearance for ventilation of the under-roof space. The installation of lathing in a cold attic is no different from insulated roofs. The dimensions of the sheathing and its pitch determine the type of roofing being installed.

Cold attic temperature

To prevent ice and icicles from forming on the roof, it is necessary to maintain the correct temperature and humidity conditions in the attic. If the thickness of the thermal insulation material is insufficient, significant heat losses occur through the ceiling. Warm air, heating the roof covering, causes snow to melt and ice dams to form. By choosing the right insulation layer, this can be avoided.

The effectiveness of a heat insulator can be assessed by measuring the temperature of the top layer of insulation. The electronic thermometer is immersed in insulation by 10-20 mm.

As you can see, the design of a cold attic pie is not particularly complex in design. The main task is to ensure the necessary intensity of ventilation and the thickness of the thermal insulation layer in the ceiling.

Cold attic: ceiling pie, device, ceiling vapor barrier and waterproofing

Construction and design of a cold attic pie. Vapor barrier for ceilings and waterproofing in a cold attic. Optimal temperature for the attic.

Roofing pie for a cold attic

There are two types of attic space - a cold attic and a combined attic or attic. In a cold attic, insulation is laid horizontally across the attic floor, and the temperature inside the cold attic is about the same as outside.

The temperature inside a cold attic should not exceed 4 °C outside air temperature (rules and standards for the technical operation of housing stock, decree No. 170 of September 27, 2003, clause 3.3.2), i.e. if the temperature outside is -15 °C, then in the attic it should be no more than -11 °C. If this difference is greater, then, for example, at an outside temperature of -5 ° C, the slope will heat up, the snow on the roof will melt and flow onto the eaves. The cornice will not heat up, because... there is no warm room underneath, and the water on it will turn into ice, forming icicles. The more ice that forms on the eaves, the greater the chance of leaks, the higher the load on the roof and the higher the risk of ice breaking, which can lead to tragic consequences. All this reduces the service life of both the roofing covering and the roof as a whole.

The roofing pie for a cold attic can be divided into two parts. The first part is along the floor between the attic and the living space. The second part is along the slope.

The first part of the roofing pie, depending on the type of ceiling, looks like this:

The insulation is laid in several layers with joints spaced apart to eliminate cold bridges.

The second part of the roofing pie using flexible tiles in a cold attic looks like this:

Installation of an attic roof pie with insulation

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

Design features

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

Cold attic roofing pie and warm attic significantly different. In the first case, fewer structural layers are used. Typically these include rafters, waterproofing, sheathing and roofing. When arranging residential attic premises under the roof, the correct roofing pie consists of the following layers, located from bottom to top:

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

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

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

Features of each layer

Next we will look at the attic cake layer by layer, indicating the design features, as well as the nuances of selecting and laying materials. We will consider all layers of the attic roof structure, moving from the room to the outside.

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

Vapor barrier

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

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

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

The following materials are used as vapor barrier:

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

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

Rafter system

For the manufacture of pitched roof rafters in a private house, elements made of wood are used coniferous species not lower than grade 1 with a moisture content of no more than 15%. The optimal rafter section is 150x50 mm. In the middle climate zone of our country, to effectively insulate an attic roof, it is necessary to use thermal insulation material 200 mm thick. As you can see, a rafter height of 15 cm will not be enough, so a beam with a cross section of 50x50 mm can be attached to them from below.

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

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

Insulation

The most important thing in the design of an attic roof is the insulation layer, because the comfort of living in the attic, as well as the level of sound insulation of the premises, depends on it. For thermal insulation of pitched structures, the following is usually used:

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

Advice: to insulate the attic, it is better to use soft mineral wool slabs based on basalt. They are easy to install in difficult areas and fit tightly to the rafters without forming cold bridges.

For each construction region, the thickness of the thermal insulation material is calculated individually. Minimum layer insulation 150 mm. For regions with harsh winters, it is necessary to use thermal insulation material with a thickness of at least 20 cm. In this case, the insulation is laid only on dry rafter wood. Otherwise, moisture will penetrate into the thermal insulation material and reduce its effectiveness.

Waterproofing

The main purpose of waterproofing is to protect the insulation from moisture penetrating from the roof, as well as the ability to transmit water vapor that will evaporate from the insulating material. This is why vapor barrier film is not suitable for these purposes, because it does not allow water vapor to pass through. Special materials are used to waterproof roofs:

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

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

Condensate films are used for roofing made of euro slate and metal tiles, since they do not allow water vapor to pass through. Wherein excess moisture from the heat-insulating material accumulates on the fleecy side and is discharged outside through the ventilation gap. In such structures, it is necessary to create a second ventilation gap between the waterproofing carpet and the coating so that condensation does not accumulate on the back side of the roof.

Counter batten and sheathing

If it is necessary to arrange ventilation of the under-roof space, then counter battens are placed on top of the waterproofing carpet. To do this, use a beam with a section height of 30-40 mm, which is nailed in the direction of the rafters.

Next comes a layer of sheathing. It can be continuous or sparse. The first option is installed under soft roofing coverings, for example, flexible tiles, and is made from OSB or moisture resistant plywood. A deformation gap of 2-3 mm should be left between the elements of the continuous sheathing. In the second case, 25 mm thick boards are used, which are nailed across the rafters in increments of 30-40 cm. After this, the roofing covering is laid.

Pie of attic roof and proper insulation roofs

Design features of the mansard roof pie and description of the layers. Rafter system, vapor barrier, waterproofing and insulation. Counter batten and sheathing.

How to arrange a roofing pie under a soft roof: general principles and analysis of construction options

To an uninitiated person in the intricacies of construction, the roof appears in the form of an accessible coating that protects his household from weather adversity. In fact, this is a complex structure, each element of which must flawlessly perform the work assigned to it. The ingredients are stacked in layers like a culinary product that shares its name with roofing system. Layers are laid in a certain order, violation of which threatens a noticeable decrease in consumer characteristics. The service life of the roof and the heating technology of the house as a whole depend on how correctly the roofing pie is constructed for a soft roof.

Types of soft roofing structures

Roofing pie is a generalized technical term that combines a number of structures with a similar “layered” structure. The combination of layers should protect the home owners from atmospheric attacks and protect the internal filling of the pie from premature deterioration.

The standard structure of a roofing pie includes the following required components:

Vapor barrier. Prevents the penetration of vapors from internal space houses and moisture condensation on the building materials used in the construction of the roof;
Thermal insulation. Helps retain heat, protects against noise, winds, and cold temperatures coming from outside;
Waterproofing. Prevents the penetration of rainwater and melted winter precipitation into both the roof structure and the building;
Decorative coating, which simultaneously performs the work of wind protection.

The category of soft roofs includes materials with excellent waterproofing qualities. These include bitumen roll representatives, piece analogues, mastics and a new generation of membranes. A couple of decades ago they served only as a barrier against water, but now they also successfully play the role of decorative coatings. This is due to the improved external surface and the development of installation methods that allow super-thin materials to be attached to any type of base.

Combination of insulating and decorative properties made it possible to reduce the number of main layers in the roofing pie to 3, if one of the types is used for arranging the roof roll materials.

When laying bitumen shingles, waterproofing is not completely abandoned. However, it is laid as an additional waterproof layer and covers the roof either completely, if the slope of the slopes does not exceed 18º, or partially in strips along the overhangs, along the ridge and valleys, around pipes and at junctions on roofs with slopes steeper than 18º.

The above list of main roofing layers has the nature of general recommendations. In fact, it is modified by reducing or adding functional elements, because the scheme for forming an ideal roofing structure is influenced by a number of significant circumstances, such as:

type and purpose of the object being developed, i.e. is it a residential building or a domestic structure;
temporary or permanent use, determining the use or rejection of thermal insulation;
the shape of the roof and the steepness of its slopes, directly related to the choice of materials for the roofing;
type of base for installing a pie and laying a soft roof;
the presence of an exploited or unexploited attic;
regional climatic features, according to which the thickness of thermal insulation is determined;
compatibility of construction layers, because in case of incompatibility, separation or migration layers will be required.

A well-designed soft roof pie is constructed taking into account the entire range of the listed conditions. Without information about the specifics of the project, no one will give exact recommendations, but it is worth familiarizing yourself with the principle of construction, regardless of whether you will build the cake yourself or hired roofers will do its installation.

Principles of constructing a roofing pie

Let's look at the most common pie designs for soft roofing used in private construction. Flat and low pitched roofing structures They are rarely built over low-rise buildings. However, there are adherents of the strict cubic forms of the techno or high-tech style, and their numbers are steadily growing. Most often, flat roofs are erected over bay windows, attached terraces, utility compartments of the building, garages, etc. They are covered with bitumen-polymer materials or a membrane, laid on reinforced concrete floors or a base made of galvanized profiled sheet.

The most popular in private construction is bituminous shingles, used in the construction of pitched roofs with a slope of 12º or more. It is used mainly to cover truss systems erected over dachas and country houses. Let's start with it.

Roofing pie for flexible tiles

Soft tiles are used to cover buildings with cold attics and houses with insulated attics, the designs of which, of course, have radical differences. In the first case, there is no need to use insulation, in the second, thermal insulation is a mandatory component. Both options require a continuous sheathing made of antiseptic-treated boards, sheets of moisture-resistant plywood or OSB-3 oriented strand boards.

The simplest non-insulated option

The scheme for laying a soft roof over an uninsulated attic is extremely simple:

a counter beam installed across the rafters is nailed to the rafter legs. The recommended size of the beam is 50x50; it is attached with two rough nails to each rafter beam. The installation pitch of the counter beam depends on the pitch between the rafters. If the standard distance is 0.7-0.9 m, the block is nailed after 30 cm;
slabs of continuous sheathing are laid on the counterbeam in a staggered manner so that there are no cross-shaped connections between them. The edges of the slabs should rest on the counter-lattice elements. Fasten the slabs every 15 cm with rough nails to the block;
A self-adhesive waterproofing carpet is laid, the installation of which is carried out depending on the steepness of the slopes. When the slope is 18º or more, only the slopes, ridge, valleys, junction areas and pipe passages through the roof are covered with waterproofing. Less steep roofs are completely covered with an insulating carpet;
Soft tiles are installed on top of the waterproofing barrier.

If a continuous sheathing is constructed from boards, then the need for a counter-lattice is automatically eliminated. The boards are fastened directly to the rafter legs and laid with a gap of 3 mm between the elements.

Installation of an insulated roof

The pie for an insulated roof is much more complicated. Its design is complemented by thermal insulation. And if it exists, then you will need a vapor barrier material that protects the insulation from moisture accumulation. The result of moistening is a decrease in insulating characteristics and the accompanying processes of rotting with subsequent destruction. Ventilation is also needed to remove condensation from under the roofing, which is unable to pass drops dangerous to wood on its own.

The layout of layers of roofing pie for an insulated pitched roof, which involves the use of an attic, is as follows:

On the inside of the rafter system, a vapor barrier membrane is attached directly to the rafters with a stapler. It is laid parallel to the overhangs in strips from bottom to top. The strips are connected into a single web with double-sided tape;
Once the vapor barrier has been installed, a counter-lattice is constructed from the bar, again from the inside, the installation step of which depends on the material of the planned internal lining of the attic. For example, under plasterboard sheathing, it is advisable to place the sheathing bars at a distance of 40 or 60 cm;
On the outside of the roof, auxiliary struts are mounted between the rafter beams. They are required to hold the insulation boards. The spacers are placed in increments of 2-3cm smaller than the height of the insulating board. So it is necessary that the thermal insulation is firmly fixed in the compartments created for it, “straightening out” after slight compression during the installation process;
The resulting semblance of a honeycomb is filled with heat-insulating material, the thickness of which should be 3-5 cm less than the thickness rafter legs. This is a necessary condition for proper ventilation roofing pie;
the counter-lattice is constructed again. It is nailed to the rafters along their direction to form ventilation ducts - roof vents;
attached to the outer counter-lattice continuous lathing, on top of which an additional waterproofing carpet is laid;
soft tiles are laid.

To install a warm roof with soft tiles in the northern regions, sometimes the thickness of mineral wool insulation of 15 cm is not enough - a generally accepted standard for the middle zone. Then, on the outside, first a tier of counter beams is installed transverse to the rafters for laying the second layer of insulation, then a beam is installed along the rafters for installation of a continuous counter batten.

If you lay it down bitumen shingles they are planned on top of low slopes constructed from reinforced concrete slabs or arranged by means of a slope with cement-sand screed poured on top; the vapor barrier is laid on a concrete or cement-sand surface. A board is installed on top of the vapor barrier on the edge in increments of up to 90 cm, and then required amount tiers of counter-lattice.

Roofing pie with wooden elements cannot be closely adjacent to chimney pipes. The required distance from the pipe walls can be found in SNiP 41-01-2003. The empty space is filled with non-flammable mineral wool material, and an apron made of galvanized or laminated metal is installed outside around the pipes.

Stages and principles of constructing a roofing pie under soft tiles will present a video:

Roofing pie for rolled materials

For the construction of roofs with a slight angle of slope, with a spread from 1º to 12º, bitumen-polymer materials or roofing membranes are used. It just doesn't make much sense to install custom shingles on them. And the patterned aesthetics of flexible tiles on flat and almost flat roofs will delight only birds.

There are no significant differences in the set of layers for piece and roll material. The sequence is similar: vapor barrier → insulation → hydrobarrier - also a decorative coating and wind protection. However, the installation of a roofing pie has its own specifics. Continuous sheathing and counter beams are not used. The layers are laid without auxiliary wooden elements on concrete floors, cement-sand screeds, corrugated sheets, prefabricated leveling structures. Therefore, we focus attention not on the sequence of installation actions, but on the installation features.

Principles of vapor barrier design

The following materials serve as a vapor barrier layer for laying roll materials:

bitumen and bitumen-polymer vapor barrier, fused onto a concrete or cement-sand base, including cement-sand insulation with vermiculite, expanded clay, perlite in the form of filler in case of a slope slope of more than 6º. If the slope is less, bitumen vapor barrier can be laid without gluing or fusing to the base.;
polyethylene reinforced or non-reinforced vapor barrier, laid loosely along the corrugations of the profiled sheet or glued to it if the slopes are inclined more than 6º.

In the construction of a soft roof using prefabricated screeds made of plywood or OSB boards, any type of vapor barrier material can be used, but the recommended option is a bitumen-polymer vapor barrier with a polyester fabric base. However, on concrete surface It is also not prohibited to put polyethylene, but before this you should arrange a separating layer of glassine.

The vapor barrier layer is laid in the form of a kind of pallet extending onto the vertical planes of adjacent walls and parapets. The height of the sides of the pallet is calculated as follows: the thickness of the thermal insulation layer plus 3-5 cm. Similar sides are installed around the intersection of the roof with chimney pipes and other communications.

Both vapor barrier options must be combined into a continuous sheet. Strips of bitumen and bitumen-polymer material are laid with an overlap of 8-10 cm on the sides and 15 cm in end connections and welded gas burner. The connection of polyethylene strips is made using adhesive tape.

Rules for laying thermal insulation

You can insulate a soft roof with a roll covering using literally any material, but mineral wool boards and foam polystyrene are considered priority. On concrete bases and cement-sand screeds, the insulation system is laid in one tier, on corrugated sheeting in two so that the joints of the elements of the upper row are not located above the joints of the lower layer.

The hardness of mineral wool for single-layer insulation is 40 kPa with a compressibility of 10%. To construct two-tier thermal insulation, it is not necessary to use slabs with equal rigidity. The bottom row can be folded with material with a strength rating of 30 kPa, the top row 60 kPa.

If a polymer membrane is used as a waterproofing and decorative roofing covering, a separating layer of fiberglass or geotextile must be laid between it and the polystyrene thermal insulation. Otherwise, the membrane will lose its consumer qualities before the time guaranteed by the manufacturer due to the gradual migration of plasticizers into the adjacent material. A separating layer is also required when installing an inverted ballast roof if polymer coating spreads over the bitumen vapor barrier layer.

Laying mineral wool slabs on corrugated sheets without first constructing a prefabricated screed from plywood or OSB sheets can be done if the thickness of the thermal insulation is twice as large as the distance between adjacent corrugations. If reality does not meet this condition, a prefabricated screed is constructed before laying the insulation.

The installation of thermal insulation under a roll covering requires compliance with the following rules:

the thermal insulation material is attached separately from the covering laid on top;
with the mechanical fastening method, each thermal insulation slab and its individual part is fixed at two points. The insulation is fastened to the corrugated sheet using steel self-tapping screws with a plastic sleeve in the shape of a fungus. Plastic bushings are not used if the slope of the slopes is more than 10º. In any case, they are attached to the concrete base with screws with dowels and metal plates;
The insulation boards are glued to bitumen-polymer mastic. Gluing is possible if the area of the surface “planted” on the adhesive composition is at least 30% of the area of the insulating board;
Insulation boards are laid with mandatory seam spacing so that weak areas are distributed evenly. Elements of the second tier, if there is one, are shifted relative to the first by at least 20 cm, both along the side and end lines;
seams in insulating carpets wider than 5mm must be filled with heat-insulating material.

The use of rigid insulation is justified economically and technologically. It allows you not to install a screed on top of the insulation, which is mandatory for fill-in thermal insulation.

If it is necessary to construct a roof slope to completely free the surface from atmospheric water and dirt, the thermal insulation is supplemented with slope-forming devices. Most often they are made from wedge-shaped slabs of mineral wool or similar polystyrene foam parts, less often from backfill insulation followed by pouring cement screed. A slope on a concrete base can also be done by pouring cement and sand, which is unacceptable for forming a slope on a base made of a profiled sheet.

Additional layers of roofing material

An additional barrier against atmospheric water is installed in areas of high load. It is laid in strips along the ridge, overhangs and junctions with fillets constructed in advance, in valleys, around penetrations and points internal drain. It is constructed either from strips of bitumen-polymer roofing coating, or from a special self-adhesive hydrobarrier.

The construction of the roofing pie is completed by laying the rolled covering and fixing it by fusing, gluing or fastening with self-tapping screws with bushings or plates.

The presented schemes for constructing a roofing pie do not contain precise recommendations. We brought general rules, taking into account which will ensure flawless operation and long service life of the roof in middle lane. In the case of construction in northern latitudes, the proposed options require modification.

Roofing pie for a soft roof: general principles of construction from a pro

A properly constructed roofing pie for a soft roof will ensure a normal microclimate inside the house, guarantee a long service life of the structure, and eliminate the need for repairs.

Are you insulating your house for winter and don’t know how to insulate the attic floor using wooden load-bearing beams? Having gained experience in this matter, I will definitely convey technical points thermal insulation, and I will also describe step by step the procedure for carrying out the work.

Why insulate an attic?

We must not forget that a significant part of heat loss occurs through the roof. Therefore, when constructing buildings with cold attics, it is very important to pay attention to proper thermal insulation of the ceiling between the heated room and the attic.

Below I will try to explain in an accessible language how attic insulation affects the internal microclimate and overall heat loss in the house:

Purpose of the attic. Any unused attic under a sloped roof is essentially a buffer technical floor between the street and residential premises. Its purpose is to smooth out significant changes in air temperature inside the house and outside;
Temperature conditions. At any time of the year, during the day the air temperature inside the attic will be several degrees higher than outside. Thus, in winter there will almost always be negative temperatures in the attic, and on sunny summer days there will be intense heat;
Heat losses in winter. When the temperature of any substance increases, its density always decreases. Therefore, in heated rooms, heated air from household heating devices, always rises up to the ceiling. If the ceiling has insufficient thermal insulation, then during the cold season, all the heat from the room will go outside through the attic;

Excess heat in summer. On hot summer days this process will occur in reverse. The air in the attic will become very hot from the hot roof in the sun, and then transfer its heat through the uninsulated ceiling into the apartment.
Reverse air circulation. After touching an uninsulated ceiling, the heated air quickly cools down, and due to the increase in density, it sharply sinks down. Indoors, this leads to excessive reverse air circulation and the constant formation of drafts, which have an adverse effect on the health of residents;
High humidity. When heated, humid air comes into contact with a cold, uninsulated ceiling, small drops of condensation may form under the ceiling. This will lead to an increase in air humidity in the house, and will also contribute to the appearance and development of mold on the walls and ceiling;

Economic factor. Confirmed heat loss through an uninsulated roof is at least 20-30%. This means that proper insulation of attic floors wooden beams, will allow you to save up to 30% of fuel during each heating season. Air conditioning in summer period, will also require lower costs;
Damage from a “warm” attic. Among other things, the penetration of warm air into an uninhabited attic, from time to time, can lead to unpleasant consequences:

As warm and cold air mixes, condensation will begin to form in the attic. Drops of water will settle on all surfaces, which will lead to rotting and destruction of the wooden supporting structures of the roof;
From the warmth of the attic, the snow masses on the roof slopes will gradually begin to melt. Thawed water will freeze as it flows down. This can lead to the formation of large icicles along the edges of the roof, as well as freezing of rain gutters and downspouts.

All the factors described are characteristic not only of residential buildings. They should be taken into account when designing and constructing any outbuildings on the site in which the heating system will be used (for example, a garage, bathhouse, barn, etc.).

Stage 1: Selecting insulation

When choosing materials for ceiling insulation, you should be guided by several criteria. In addition to low thermal conductivity, insulation attic floor must have the following qualities:

Moisture resistance and mechanical strength. The material should not be deformed or destroyed under the influence of mechanical load, and should not change its properties in the event of direct contact with water;
Heat resistance. The insulation must be absolutely non-flammable and should not be destroyed under the influence of high or low temperatures;

Light weight. In order not to create additional load on the load-bearing structures of the building, the thermal insulation of the attic floor should be quite light, so you need to choose insulation with a low specific gravity;
Vapor permeability. To ensure normal temperature and humidity conditions in residential premises, all finishing and Construction Materials must allow air and water vapor to pass freely;
Environmental Safety. Insulation for residential buildings must be hypoallergenic and chemically neutral. It should not contain harmful volatile compounds or toxic substances;
Lack of organic matter. I recommend using exclusively mineral or polymer based materials. They do not contain organic substances, therefore they are not susceptible to mold, and are not suitable for food for small rodents and pests.

Taking into account all these factors, several types of thermal insulation materials can be used to insulate attic floors:

Mineral wool. Produced in the form of rolls or rigid mats, from intertwined frozen fibers of molten sedimentary rocks. Mineral basalt wool is characterized by all of the above qualities, so it can be considered the most suitable material. Below I will give some recommendations for its use:

Basalt wool itself is very soft. To prevent it from being pressed or dented while walking, plank flooring should be laid on top of it in the attic;
When choosing insulation, I advise you to give preference to rigid slabs that are covered on one side with aluminum foil;
They need to be mounted with aluminum foil inside the room. It simultaneously reflects heat and acts as a vapor barrier layer.

Glass wool. It has a similar manufacturing technology, only molten glass is used as the raw material for its production. I do not recommend using this material for insulating residential buildings for the following reasons:

Glass fibers are more fragile, so they can break under load;
The price of glass wool is much lower, but after creasing or getting wet, it partially loses its heat-insulating properties;
Small particles of glass penetrate deeply into a person's skin and cause severe irritation.

Expanded clay. This bulk insulation is produced in the form of small round pellets of light brown or red color. Expanded clay balls are formed as a result of sintering special varieties of red clay under conditions high temperature.

Expanded clay has the following characteristic qualities:

The internal structure of the material has many closed pores, so it has low thermal conductivity;
Each pellet is covered on the outside with a dense glassy layer of baked clay, so moisture practically does not penetrate inside it;
Small crumbly expanded clay pellets freely fill the entire volume, so they are convenient to use for insulating hidden cavities and hard to reach places in building structures;
Thanks to its mineral base, this material does not burn at all, does not emit harmful substances, is not susceptible to mold, and is not suitable for rodent food.

Styrofoam. This polymer thermal insulation material is made by hot molding from small round granules of polystyrene foam. It is usually produced in sheets measuring 1000x1000 mm, which can be from 10 to 150 mm thick. The following features are characteristic of polystyrene foam:

Of all existing types of insulation, it has the lowest thermal conductivity;
The foam contains no organic substances, so it is absolutely not afraid of water, does not rot and does not contribute to the formation of mold;
By itself, polystyrene foam does not burn and does not support combustion, however, when exposed to high temperatures, it can emit toxic gases and acrid thick smoke;
Due to the polymer base and closed porous structure, foam sheets do not allow air and water vapor to pass through. For this reason, it is not very good to use for insulation. living rooms and rooms with high air humidity.

Extruded polystyrene foam Abbreviated as EPPS. It has the same composition as polystyrene foam, but is made by hot extrusion from a molten mass of polystyrene foam. The technical characteristics of these two materials are also very similar, however, EPS still has some differences:

Expanded polystyrene has a porous, uniform structure and a higher specific density;
Due to this, it has higher thermal conductivity, but at the same time is more durable, and therefore is able to bear higher weight loads;
For this reason, I recommend using it for insulating unheated attics that will be used for storing seasonal items or household equipment.

Foil polyethylene foam. It is also called “Penofol” in another way. This roll material consists of thick foam polyethylene film, which is covered on one or both sides with a thin layer of aluminum foil. I recommend using it in combination with other types of insulation, because by itself it has specific properties:

The porous structure of polyethylene foam provides a low heat transfer coefficient, so it functions as an additional insulation;
Polyethylene film does not allow air, drops of moisture and water vapor to pass through at all, so Penofol can be used as waterproofing;
Mirror aluminum foil reflects infrared heat waves well. In other words, it does not allow radiant heat to pass through itself, and returns it back to the room.

Wood sawdust. This one is cheap and available material, is still often used to insulate ceilings in bathhouses, heated barns or small country houses. It is applied to wooden floor from the attic side, in the form of a homogeneous thick mixture of sawdust with liquid clay mortar. Despite the seeming primitiveness of this method, it has its advantages and disadvantages:

Sawdust or small shavings can be bought inexpensively, or even taken for free, at almost any large sawmill;
There can be no problems with clay either, so such insulation is easy to prepare with your own hands in the required quantity at any time;
A mixture of sawdust and clay has a small specific gravity, and after hardening it becomes quite hard. Therefore, it does not place significant stress on load-bearing beams, and allows you to walk freely on it with your feet;
Due to the mineral components, such a coating is permeable to air and steam, however, due to sawdust, mold may form on it, or mice may chew on it.

All mineral-based thermal insulation materials, to one degree or another, are capable of allowing water vapor and air to pass through. To protect such insulation from the formation of condensation or moisture penetration from the outside, they must be installed using a vapor-permeable waterproof membrane.

Stage 2: Preparation of materials and tools

In addition to insulation, for the work you will need lumber, waterproofing, as well as the usual set of carpentry and carpentry tools:

Two hammers: one medium, weighing 200-300 grams, and one heavy, weighing 800-1200 grams;
Longitudinal and transverse hacksaw for wood. Instead of a cross saw, it is more convenient to use an electric cutting machine;
A carpenter's plane, a large wooden mallet and a set of chisels;
As for electric tools, you need to have an ordinary household drill, and it is advisable to have cordless screwdriver with a set of replaceable nozzles;

To fasten rolled materials (waterproofing, vapor barrier), I recommend using a construction or furniture stapler with a set of metal staples;
You will also need a straight metal ruler, a tape measure 3-5 meters long, building level and a simple rope plumb line;
To work near the ceiling, it is most convenient to use a folding stepladder. If it is not there, you can adapt a high strong table or homemade goats from scraps of boards;
Lumber will be needed wooden blocks section 62x62 mm, and planed edged boards thickness 25-30 mm;

As a waterproofing layer, you can use a film of foamed polyethylene and a vapor-permeable waterproof membrane;
To seal the joints of the panels, you will need metallized aluminum tape, which is usually used in ventilation systems;
Each homeowner chooses materials for finishing the ceiling at his own discretion. This could be lining board, drywall, laminated OSB or plywood, or other finishing materials;

If you plan to use mineral or glass wool for insulation, then I recommend purchasing a special protective suit that is designed to work with these materials. Otherwise, severe irritation may occur on exposed areas of the skin from small glass fibers.

Stage 3: Filing the rough ceiling

During construction attic floor or construction sloping roof, you can do without expensive and heavy concrete floor slabs. Instead, the entire load from the roof is carried by wooden load-bearing beams made of logs or timber, with a cross-section of at least 120x120 mm. They are usually laid on top of two main exterior walls, perpendicular to the long side of the house.

Such beams serve as a supporting structure for the ceiling itself. top floor, and for the floor of the attic. The same beams will be used for installing insulation between residential building and the attic. This type of ceiling is called hemmed, because both the rough and the finished ceiling are hemmed from below to the load-bearing beams.

Before insulating the attic floor, you need to mount the rough ceiling:

Illustration	Description of work
	Installation of a rough ceiling. To hem the rough ceiling, you should use dry edged boards 25 mm thick, or plywood sheets 10 mm thick or more.
	Hemming boards. They must be secured to the lower plane of the supporting beams and beams around the perimeter of the room. Hemming boards must be fastened without gaps or cracks, close to each other. For fastening, use galvanized self-tapping screws 5-6 mm.
	Waterproofing. When the entire rough ceiling is hemmed to the load-bearing beams, panels of foiled polyethylene foam need to be secured to it from below. This can be done using a stapler. "Penofol" will perform the functions of heat and waterproofing. It should always be placed with a foil layer towards the warm room.
	Sealing joints. To prevent moist air from the room from entering the insulation, the ends of the polyethylene film must be wrapped on the walls by 150-200 mm. The joints between the panels must be glued with metallized tape on an aluminum base.
	Attaching the sheathing. From below, across the entire area of the rough ceiling, nail a counter lath made of wooden slats 15-22 mm thick. It is needed in order to provide a ventilation air gap between Penofol and the finished ceiling. The distance between the slats should be about 400-600 mm. In the future, a finishing ceiling covering will be attached to them from below.

Before starting work, all wooden structural elements must be treated with antiseptic and fire-retardant impregnations. Antiseptics are needed to protect wood from rotting and mold development. Fire retardants give dry wood fire retardant properties.

Stage 4: Installation of thermal insulation

After filing the rough ceiling, the transverse load-bearing beams will be on the side of the attic. Insulation will be laid in between them.

Depending on the thermal insulation materials used, further technology installation may have some differences. Therefore, below I will briefly discuss the use of the most common types of insulation.

Laying mineral wool. Mineral insulation materials, when wet, partially lose their properties. To prevent condensation from forming in the mineral wool, the entire thermal insulation layer of the cold attic floor must be permeable to air and water vapor:

Illustration

Description of work

Vapor barrier. First, you need to lay a vapor-permeable waterproofing membrane on top of the rough ceiling.

Its peculiarity is that it freely allows water vapor molecules to pass through, but does not allow bound liquid water molecules to pass through.

The membrane panels must overlap each other by at least 150 mm;

Installation of insulation. Place sheets or rolls of mineral wool in the spaces between the wooden beams. If it is very soft, then it does not need to be squeezed or squeezed much.

Lay another layer of vapor-permeable membrane on top of the mineral wool.

To prevent it from moving over time, it must be stapled to the beams and walls, throughout the entire area and along the perimeter of the attic.

Installation of foam plastic. Polymer-based insulation does not have breathable properties, so it does not allow air and moisture to pass through. There is no point in using a waterproof membrane in this case:

Illustration

Description of work

Laying foam. Panels of foam or extruded polystyrene foam can be laid between cross beams, right on top of the rough ceiling boards.

I advise laying them in two layers, so that the joints of the sheets are located in different places and do not intersect with each other.

Polyurethane foam. To prevent the insulation sheets from moving to the sides, they can be glued to the sub-ceiling using a special glue for polystyrene foam or polyurethane foam.

Thus, it is necessary to fill the entire area of the attic floor with insulation.

If there are gaps and cracks between the sheets of foam plastic, then they must also be blown out from a balloon with polyurethane foam.

Clay with wood shavings. Insulating the attic floor with a sawdust-clay mixture does not require any additional materials, and is also quite simple:

Illustration

Description of work

Preparation of the solution. To make the sawdust-clay solution plastic, the clay must be soaked in water 2-3 days before starting work.

To prepare the solution, you need to take 3-4 volume parts of sawdust, and 1-2 parts of dry red clay without large solid particles and foreign impurities.

Mix the soaked clay with water until a liquid, flowing solution is obtained;

Add sawdust to the resulting mixture and mix thoroughly until smooth.

To protect against mold formation, a small amount of copper sulfate can be added to the prepared solution.

Laying sawdust-clay mixture. Lightly moisten the supporting beams and boards of the rough ceiling with liquid clay milk.

After this, fill all the gaps between the beams with sawdust-clay mortar and leave for several days until completely dry.

Expanded clay backfill. I want to say right away that expanded clay does not have very good heat-insulating properties, therefore, in individual construction, such insulation of floors is rarely used. At the same time, it is considered inexpensive, unpretentious and the easiest to install:

Illustration	Description of work
	Preparatory work. Expanded clay pellets do not absorb moisture, and therefore are not afraid of water ingress or condensation. Therefore, they can be used both with and without a waterproof membrane. To prevent condensation from seeping through the ceiling into the house, I still recommend laying a waterproofing membrane under the pellets;
	Filling of pellets. Expanded clay pellets should be poured on top of the rough ceiling boards and evenly distributed in a thick layer over the entire area of the attic. No covering material is required on top of expanded clay.

To prevent expanded clay pellets from bunching up and spreading throughout the attic, a retaining plastic geogrid is used. It needs to be stretched in the spaces between the load-bearing beams, and then expanded clay should be poured into its cells.

Stage 5: Arrangement of the floor in the attic

Many residents use the cold attic in their private home as a storage room for storing long items, seasonal items and all sorts of things. unnecessary trash. In order for a person to safely walk on the insulated floor, the attic must be equipped with a durable subfloor.

The choice of material for installing the floor in the attic will depend on the type of insulation used:

Illustration	Features of application
	Mineral wool and polystyrene foam. These materials themselves are very soft. To prevent them from being destroyed or wrinkled while walking, the top floor covering must be sufficiently rigid. In such cases, OSB or plywood sheets with a thickness of at least 18 mm should be laid on the load-bearing beams. You can also use unplaned edged boards with a thickness of 25 or 30 mm.
	Extruded polystyrene. Has more high rigidity, so it can withstand significant loads. To prevent it from being pressed when walking, it is enough to put a light flooring of thin boards or plywood 5-9 mm thick on top of it.
	Under the weight of a person, they will crawl in different directions. To prevent this from happening, you need to lay 10 mm thick plywood sheets or light wooden ladders made of boards on top of the beam floor.
	Sawdust-clay insulation. After the solution hardens, it becomes hard like cement. A person can move freely on its surface, even without installing additional flooring.

When installing rough flooring in the attic, you should always leave gaps 15-20 mm wide between boards or sheets of plywood. This is done so that moisture and condensation can freely evaporate from the insulation.

Conclusion

Using this algorithm of work, you can easily insulate the ceiling in the attic in own home. More visual information on each method of insulation can be viewed in the attached video in this article, and I suggest leaving all your comments and questions in the comment form.

If you are completing a house, almost the finishing work has already been done and you don’t know whether to take on the attic or whether this matter can wait, and in general what is needed at this stage - this article will help you. Here we will look at the insulation of the attic floor with materials of different types, with step by step illustrations, expert advice and useful videos.

We will also reveal many important points why insulation is so necessary and what the attic floor pie should actually be like on wooden beams and on reinforced concrete slab- step by step.

What insulation is suitable for the attic?

The attic floor needs to be insulated when the attic space is not planned to be used for housing. Those. we are talking about a cold attic, the roof slopes of which are not insulated at all. But not all the same materials are suitable for covering, so they are selected for slopes.

Mineral wool: no harmful dust

So, when insulating an attic floor with mineral wool, it is correct to use the so-called tension method. Its essence is that the insulating material is first laid - and so that it fits between the beams.

After this, a slab or roll insulation made of mineral wool, with a total thickness of about 150 millimeters, and is covered with a vapor barrier film on top. After this, it’s plywood, which should be no thinner than 18 millimeters.

Expanded polystyrene and polystyrene: ease of installation

The insulation of the attic floor using expanded polystyrene is also of high quality, the main advantage of which is that there is no need for vapor barrier, and all gaps are easily sealed with polyurethane foam.

Blown-in insulation: fashion and rationality

Recently, insulation of attic floors using the blow-in method has become especially popular.

The main advantage of blown-in insulation is that it automatically fills all the voids that exist and creates an even, continuous layer. In which there are no joints, no seams and no adjoining, and for which there is no need to cut separate small pieces of prickly insulation in order to plug something.

Today, to insulate cold attics in Russia, two types of blown-in insulation are mainly used: ecowool and blown-in wool.

Ecowool up to 80% consists of cellulose fibers, which are produced from ordinary waste paper, and 20% from additives such as Buran as a fire retardant and boric acid as an antiseptic. This insulation has high thermal conductivity.

But blown-in cotton wool is obtained by grinding ordinary mineral materials for thermal insulation, which for some reason did not pass product acceptance.

For example, they did not have sufficient density or correct fiber structure. And such material is crushed and packaged under high pressure, and therefore it is easy to transport it to the site, where everything will be loosened again upon arrival.

But still, ecowool is most often used as a material. The insulation process itself looks like this: one person must stay next to the installation and monitor it normal operation while simultaneously loading material. And the second person goes up to the attic with a hose, makes a cross-shaped cut on the vapor barrier (just between the beams), inserts the hose into this cut, and fills the cavity with material.

Plus, relatively inexpensive ones are used to insulate a cold attic. bulk materials:

What insulation parameters should you pay attention to?

We in no way encourage you to purchase the most expensive thermal insulation materials to insulate your attic floor. But please note that the more and longer any famous company produces materials for this purpose, the more it pays attention to quality by changing them volume weight, improving their products and increasing thermal insulation coefficients. And this already says something.

Otherwise, always pay attention to the parameters of insulation that are important for a wooden floor, and have no significance for a concrete floor - and vice versa.

Parameter No. 1. Biostability

The point is to ensure that such insulation, which often remains open, does not harbor bugs or other living creatures. This is especially true for mice, which love to live in a warm and dry (and, most importantly, deserted) attic.

Another important requirement for attic insulation is water resistance. Raindrops or simply moisture that accidentally fall into it should not lead to the process of rotting.

Glass wool is recognized as one of the most durable insulation materials:

Parameter No. 2. Thermal conductivity

The main requirements for attic insulation are the ability to maintain thermal insulation properties for a long time.

When purchasing insulation, also pay attention to this interesting point: modern manufacturers of thermal insulation materials always indicate technical specifications three coefficients of thermal conductivity of the material at once: in a dry state, at temperatures of 10° and 25°, and humidity categories A and B.

You need to look at the thermal conductivity coefficient in a dry state, or at a temperature of 10 degrees, because this is the normal climate in the attic. For a more accurate and detailed thermal calculation, you will need a SNiP table.

Now let's note this moment. When choosing when purchasing insulation, you will probably be advised to take insulation with the lowest possible degree of thermal conductivity. But in fact, this only makes sense for residential attics, because when you have to insulate roof slopes, you cannot lay too thick materials between the rafters. Therefore, here we need materials that will conduct heat as poorly as possible, but at the same time have a small thickness.

But for the attic floor, the thickness of the insulation is not a critical factor, and you can save on this. Just take cheaper insulation, but thicker, albeit with high thermal conductivity. Everything is compensated by the height of the insulation itself.

Parameter No. 3. Weight

Depending on the chemical composition, each insulation has its own volumetric mass. Thus, materials such as basalt, glass and any other inorganic and organic compounds are most often used as a basis for fibers. From their type myself heat insulating material becomes either light or heavy. And the shape of all these materials is ensured precisely by the elasticity of the fibers: how they straighten between the floor beams.

Note that heavy insulation materials hold their shape better due to the rigidity of their fibers. And the best stability for insulating attic floors is provided by foam insulation, which in this parameter is equivalent to hard stone wool. But there is a point: the same mineral wool insulation that was inserted between the floor beams can easily straighten out and press tightly against the wood, but foam insulation will not do this, and voids are formed - the bridges are cold. Therefore, you will have to additionally use a can of foam to close all the cracks.

But if you insulate the attic floor on a reinforced concrete slab with foam-based materials, then there will only be advantages. Not to mention the fact that concrete floor the attic already has considerable weight and creates a serious load on the walls and foundation of the house, and using lightweight insulation for it is just a big bonus.

And unlike a concrete floor, an attic floor can withstand a fairly limited load. Therefore, the weight of the insulation in this regard is also not the last point. After all, there are already many variations here: the same cubic meter of thermal insulation can weigh either 11 kilograms or all 350 - this is the norm.

One of the heaviest insulation materials is basalt wool:

Parameter No. 4. Moisture resistance

Rain moisture that accidentally gets into the insulation or roof leaks should not start the rotting process. It’s bad if after six months or a year new insulation begins to decompose from the inside, while emitting bad smell dampness.

Therefore, insulation of attic floors over wooden beams and concrete is quite often done using polystyrene foam or expanded polystyrene, which are known for their almost zero hydrophobicity.

Parameter No. 5. Environmental friendliness

One more point: the attic insulation should not emit any toxic or pungent odor substances, despite the fact that, perhaps, no one will walk in such an attic.

It's all about ventilation: sooner or later, insulation molecules are picked up by the air and carried into living spaces, which can be unsafe for the residents of the house. Therefore, choose insulation that meets sanitary standards.

Parameter No. 6. Saving the form

Another important point– this is the form of stability of the selected insulation. Thus, special laboratory tests have shown that over time, heat loss through the cracks between the slabs or matte insulation can reach 40%. And this despite the fact that the material itself during the same time may not change its thermal conductivity coefficient at all, if it remains dry.

Therefore, the stability of the shape and size of the material over time is very important. For a concrete attic floor, such gaps will not be critical, because here the floor itself is quite heat-insulating, which cannot be said about the attic floor.

But the problem is that in technical information For modern thermal insulators, such parameters as shape or stability cannot be found.

Parameter No. 7. Fire safety

And the last point: the attic insulation must meet all requirements fire safety. Take the same popular ecowool, which is made not just from ordinary waste paper and pieces of newspapers. It would seem that everything is simple and ingenious, why don’t you also cut the paper smaller and just fill the attic with it? Would it be worse? After all, the principle of looseness is also involved here, like in animal fur, when air molecules get stuck between small elements.

Let's put it this way: yes, the insulating properties of this method will be no worse, but it is old dry paper and wood that most often leads to unexpected fires. That's why modern cellulose insulation are necessarily treated with special chemicals against fire.

If we are talking about the flammability of materials, then it is important that the insulation not only does not burn, but also has attenuation. Just remember that at the epicenter of the fire everything burns, both iron and concrete, but if a spark falls on the attic floor, the insulation should not catch fire. That's what we're talking about.

This is what the attic insulation cake itself should look like:

Vapor barrier issues: how, on which side and is it necessary?

For insulation of wood and concrete roofing, the vapor permeability of the insulation is of great importance. Thus, all insulation materials that are manufactured today in the form of slabs and rolls can be divided into “cotton wool” and “foam,” as construction contractors like to do.

We include thermal insulation materials made of organic and mineral fibers as “cotton” materials - these are mineral wool, stone wool and glass wool insulation. All these materials are formed by the hardening of plastic masses of various chemical origins. And all these materials have approximately the same thermal conductivity coefficient: within 0.04.

All these materials consist of fibers that are intertwined. They do not form any closed pores, and water vapor easily penetrates and escapes through them. Therefore, all cotton insulation materials are vapor-permeable materials. Why, during production, their fibers are additionally coated with a special water-repellent substance, and the insulation also turns out to be hydrophobized: the water molecule from water vapor is not allowed to penetrate inside and wet the insulation. It can only cling to its surface, and when a critical mass accumulates, it transforms into drops and rolls down. It turns out that hydrophobized cotton insulation is not a wet, vapor-permeable material.

Therefore, until now, scientists from all over the world cannot come to an unambiguous conclusion: the vapor permeability of building insulation is good or bad. Let's just say that if you are installing an attic floor on wooden beams, you better lay vapor-permeable materials on it so that the wooden rafters, which take on moisture from the lower living spaces (and water vapor always rises upward), can easily transfer it to the insulation . And they will easily come out of the insulation - just through ventilation is enough. But in terms of insulation of concrete floors, there is not much difference. But there is a point here: when using vapor-permeable insulation, it is important that the ventilation of such an attic is organized according to all the rules, and a separate ventilation system would not hurt.

Note that there are no fibers in foam insulation, since such material is literally produced from thin air. All foam insulation consists of a cellular structure, with closed bubbles and not closed ones, like a kitchen sponge. Therefore, such heat insulators can be either vapor-permeable or non-vapor-permeable. For example, extruded polystyrene foam, which is better known to us as polystyrene foam, allows water vapor to pass between the balls, but extruded polystyrene foam does not.

What’s interesting is that you can use not only one type of insulation, but two at once to compensate for each other’s shortcomings. But at the same time, a heat-insulating material with lower vapor permeability must necessarily lie in front of the insulation with high vapor permeability. That is, first polystyrene foam, then cotton wool. Otherwise, in the opposite case, a material with less vapor permeability will become a certain vapor barrier for another material, which will simply begin to rot and the moisture will have nowhere to escape.

How to insulate a concrete attic floor

If we are talking about insulating an attic floor made of concrete, then the thermal insulation must necessarily be in the form of two or three layers with overlapping joints of each lower layer. Moreover, it is very important that the entire surface is leveled so that there are no irregularities of more than 5 millimeters anywhere - this is not difficult to achieve with the help of modern leveling mixtures.

For concrete attic floors, extruded polystyrene foam slabs are ideal for thermal insulation. They don’t need a vapor barrier, but if you’re putting in polystyrene foam, it’s not extruded polystyrene foam, and then, of course, it’s needed.

Additionally, if you then need to walk on such a floor, you can make a cement-sand screed up to 4 centimeters and lay two layers of plasterboard sheets. Just be sure to make paths from masonry mesh for such a screed along which you will walk. Be sure to seal the joints between the polystyrene foam boards with tape so that cement laitance does not leak between the boards.

The attic floor itself can be insulated both at the manufacturing stage and at almost any time during the operation of the house itself. Of course, for the attic it is much more correct to insulate the ceiling before you move into your new home.

More details about the process itself:

How to insulate a wooden attic floor

So, there are two main ways to insulate an attic floor: laying a heat-insulating layer inside the attic floor structure, and laying insulation on top of it. For cold and non-residential attic It is not necessary to cover the insulation with something on top and build a full floor. But then be sure to leave walking ladders - separate paths made of sparse flooring throughout the entire area of the attic, this is necessary for roof maintenance.

A vapor barrier must be placed under the insulation, in the form of a trough, so that it can protect the insulation from water vapor that comes from the lower living quarters. But there is an exception to this rule: if the insulation was laid with good resistance, for example, it is foam or extruded polystyrene foam, then a vapor barrier is not needed here. But if we are talking about an attic with a particularly humid regime, for example, above a kitchen or sauna, then a serious vapor barrier layer needs to be installed here.

Another method is tension, when the vapor barrier only sags slightly between the beams. The disadvantage of this method is that the insulation between the beams is not inserted tightly enough.

And if the ceiling is also made of ready-made companies, then this option is not suitable at all, because such voids quickly become so-called cold bridges. Therefore, in Russia, the more popular method is in which the insulation is first laid, then a vapor barrier is covered, and only then with the finishing flooring.

So, here's what the whole insulation process looks like:

Step 1. A vapor barrier is secured between the beams using a construction stapler.
Step 2. Next, mineral wool slabs are cut so that their width corresponds to the pitch of the beams.
Step 3. These slabs are carefully inserted into the gap between the beams.
Step 4. While the ceiling below is not yet ready, so that the insulation does not fall between the beams, it is supported by rough bars or a strong thread stretched specially for this purpose.
Step 5. Next, a diffuse membrane is quickly installed on top of the insulation - so that steam can easily escape through it, and drops from above from the slopes do not penetrate inside.

But let us also note the following point about the last step. Many experts believe that no diffuse membranes or windproof films are needed for insulation, because in a cold attic the insulation will dry due to natural ventilation of convection air flows, which easily penetrate through openings and dormer windows.

How to leave walking ladders in insulation

If you use soft thermal insulation materials to insulate the attic floor, you need to make walking ladders over them - but only so as not to create cold bridges. Therefore, it is better to take either hard materials or insert the ladder legs directly into the insulation.

That's all the tricks for insulating attic floors of different types!