Do-it-yourself roof insulation from the inside. Roof insulation technology. We insulate the roof (roof) from the inside with our own hands Insulating a soft roof from the inside
Insulation of the roof from the inside is carried out not only in order to create an additional room in the attic, but also to maximize heat retention throughout the entire house.
If the building has an attic roof, then insulation is carried out directly on the roof itself, which is not only the roof for the future room, but also the walls. If the structure has one slope, then most often the thermal insulation is installed in the attic floor.
The third option for thermal insulation measures is used in regions with harsh climates, where both the roof itself and the ceiling are insulated from the inside.
Types of insulation used
The modern building materials market offers quite a lot types of insulation, of which you can choose the one suitable for any thermal insulation work.
- Bulk materials are sawdust, expanded clay of different fractions, slag, dry leaves or pine needles. These insulation materials are used for filling into the attic floor, and they perfectly protect the lower rooms of the house from the penetration of cold, but they will not be able to make the attic itself warm.
- Mineral wool of various types, polystyrene foam, penoflex and polyurethane foam are suitable for insulating both attic floors and.
All these materials are quite light, so they will not weigh down the structure of the roof and the entire house, but will make it much warmer. Technologies for installing thermal insulation materials differ from each other, so it is worth considering some of them.
It should be noted that with the advent of auxiliary materials that facilitate the work process and are aimed at protecting the thermal insulation itself from external influences and preserving its performance qualities, it has become easier to carry out the installation process.
Video: mineral wool is an excellent material for roof insulation
Prices for mineral wool
Mineral wool
Vapor barrier coatings
One such material is vapor barrier film. It is designed to protect wooden structures and insulation from exposure to vapors that occur during temperature changes and lead to the formation of condensation. Excess moisture provokes the appearance of mold, which destroys the structure of the wood, reduces the thermal insulation characteristics of the insulation and contributes to the appearance of an unpleasant odor in the room.
The vapor barrier membrane is fixed to the roof or ceiling structure before laying insulation materials.
When using a vapor barrier film in a heated room, it is placed only under the finishing layer of the walls.
To protect structures that are exposed to high temperatures on one side, and on the other - low, vapor barrier must be located on both sides. Such structures include wooden attic floors and roofing when it is insulated. Concrete slabs do not require the installation of vapor barrier materials.
The protective film can have different thicknesses and be of different types - regular non-woven material or a foil membrane. If the latter is used on an attic floor structure, it is laid with foil down, as it reflects the heat rising from below to the ceiling, thereby preventing it from escaping outside. The sheets of material are fastened together with foil tape, which helps create a tight seal.
Prices for various types of insulating films
Insulating films
Insulation of the attic floor
Any insulation measures are best carried out during the process of building a house, but, unfortunately, very often it is done only when they feel the winter cold.
Before filling or laying insulation, you need to carry out preparatory work. This is especially important if fine-grained expanded clay and sawdust slag are used.
- Previously, when there were no modern auxiliary materials on sale, the wooden attic floor was prepared as follows:
— The boards attached to the floor beams were carefully coated with a solution of clay or lime having a medium-thick consistency. These natural materials create good tightness of the ceiling, but at the same time, they allow the entire structure to “breathe”.
— After the clay or lime had completely dried, insulation work was carried out. Previously, slag, sawdust, dry leaves, or a mixture of these materials were mainly used for this. They were poured between the beams onto prepared boards.
It should be noted that the old traditional method is quite reliable, and therefore some builders even prefer it to modern ones to this day.
- In modern construction, a special vapor barrier film is mainly used for flooring under insulation. Its canvases are laid completely over the entire area of the attic, overlapping by 15-20 cm, deepening between the floor beams and secured to boards and beams. It is recommended to glue the canvases together with construction tape.
The film will become an additional barrier to the escape of heat from the premises of the house through the ceiling, since the heated air rising, not finding a way out, will descend and remain inside the house.
- Next, insulation material is poured onto the film, mineral wool is laid, expanded clay is poured, or the openings between the beams are filled with ecowool. You can also use previously used insulation - slag or sawdust.
- To avoid the occurrence of cold bridges through wooden beams, a layer of thin insulation must also be attached to them.
- Another layer of vapor barrier is laid on top of the insulating material, just as before - overlapping. This layer of film is secured to the floor beams with slats, which are more often called counter slats.
- A covering of boards or thick plywood is laid on top.
Sometimes a vapor barrier can be fixed from the inside of the room to a wooden ceiling, but in this case it will need to be finished, for example, with plasterboard boards. They will level the ceiling and become another additional insulating layer.
Insulation of roof slopes
When insulating roof slopes, as well as when insulating floors, use mineral wool and polystyrene foam, but mineral wool in this case it is preferable, since it has practically zero flammability.
If you still decide to use polystyrene foam, it is recommended to purchase an extruded version. Although it has a slightly higher thermal conductivity, it is not flammable, and this is very important for wooden structures.
To insulate roof slopes, different systems are used, but they always contain a layer of vapor barrier material, insulation, waterproofing and counter-lattice.
1. This diagram shows one of the options for the insulation “pie”. It is used in the construction of roofs and roof coverings.
- It is laid on the rafter system. Typically, high-density polyethylene (more than 200 microns thick) is used for this layer - it will protect the roof not only from moisture, but from wind penetration under it. The film is laid with an overlap of 20 ÷ 25 cm and secured to the rafters using staples and a stapler.
- A counter-batten with a thickness of 5 ÷ 7 mm is fixed on top of the film on each rafter. It is necessary so that the roofing material does not adhere directly to the waterproofing film, and there is a small distance between them for air circulation.
- Next, if the roof slopes will be covered with soft roofing material, it is necessary to lay plywood on top of the counter-battens. In the case when slate or other rigid sheet material is used, a lath is installed instead of plywood; the width between its slats is calculated according to the length of the sheets of roofing material.
- When the sheathing is ready, the roof is covered with the selected coating.
After this, you can move on to insulation measures, which are carried out from the inside, that is, from the attic.
- Mats of mineral wool or other insulation are laid between the rafters. They should fit as tightly as possible between the elements of the wooden structure. Installation of mats is carried out starting from the bottom, gradually rising to the ridge. The insulation should have a thickness the same as the width of the rafters or slightly less her, approximately 10 ÷ 15 mm.
- The laid insulation is covered with a vapor barrier film, which is secured to the rafters with slats. The film is also overlapped and glued with construction tape.
The last stage is decorative finishing of the walls of the attic room - Further, if the attic space is to be equipped as a living room, then the entire surface is covered with plasterboard or clapboard. In addition, in this case, in addition to the walls and ceiling, the floors, that is, the attic floor, are also insulated.
2. Another option could be a thicker insulating “pie”, which is also installed immediately when installing the roof.
- In this case, a waterproofing windproof film is also laid on the rafter system.
- A sheathing for roofing material is placed on top of it.
- Next, from the attic side, the first one is laid between the rafters. a layer of insulation that must have equal to the width of the rafters.
- Then transverse slats are placed on the rafters at a distance from each other equal to the width of the insulation of the next layer. In this case, thinner insulation is used. Its thickness should be equal to the thickness of the padded cross slats.
- After this comes a vapor barrier film, which is secured to the slats with brackets.
- The interior finishing material is then attached to the slats.
If the roof is insulated in an already built house where the roofing covering is fixed, then a vapor barrier is secured to the rafters from the attic side with brackets, and only after that the insulation is laid. Next, the process proceeds in the same way as in the previous options.
Roof insulation from the inside with polyurethane foam
Insulation with polyurethane foam proceeds differently than with bulk materials or mats of mineral wool and polystyrene foam.
This method of thermal insulation has recently become increasingly popular and is suitable for both ordinary attics and the attic, which will later become an additional room.
If the attic is ventilated and there will be no living space in it, then only the attic floor is insulated. To do this, it is recommended to moisten the boards and beams for better adhesion, and a thin layer of polyurethane foam is sprayed onto the wet surface between the beams. After it foams, increases in volume and hardens, if necessary, another layer is applied. Such insulation will be quite enough to keep the house warm, since the foam penetrates into all the cracks and seals them hermetically.
If the height of the attic allows you to build a room in it, or the attic is an attic superstructure to the house, in addition to the ceiling with polyurethane foam, the roof slopes are also insulated.
Spraying begins from the bottom of the structure, gradually rising to the ridge. Foam is sprayed between the rafters, and its lower layers, rising and hardening, will serve as support for the next upper layers applied.
A similar or attic creates a completely sealed, unventilated space. Polyurethane foam will retain heat well indoors in winter and will not allow the attic to overheat on hot summer days. However, ventilation should still be provided, since the room must receive air flow.
This type of thermal insulation has the following advantages over other insulation materials:
- The polyurethane foam coating has no joints or seams throughout the entire insulated area.
- A significant reduction in temperature changes in the attic and rooms on the lower floors is achieved.
- The building receives reliable protection from low and high temperatures affecting the house from the outside.
- This method of insulation shows a high payback in a very short time, by reducing heating costs due to the low thermal conductivity of the sprayed material.
- When spraying polyurethane foam directly onto the roof, it gets extra rigidity and strength, as for the roofing coating forms a reliable connection with the entire roof structure. At the same time, the polyurethane foam layer does not lead to significant weighting of the roof.
- Convenience application - foam covers all hard-to-reach areas of the roof and ceiling, penetrating into all large and small holes and cracks, expanding and sealing walls and floors.
- Polyurethane foam is highly resistant to moisture, to the appearance any forms of biological life, high and low temperatures, prevents the emergence and development of wood decay processes.
- Foam not only provides excellent thermal insulation for rooms, but also insulates well from extraneous noise from the outside.
- Polyurethane foam does not shrink, wrinkle or soften.
- The insulation has a fairly long service life, which is about 30 years.
- The material does not emit substances toxic to the human body or unpleasant odors.
The “disadvantages” of sprayed insulation include the following factors:
- The material is toxic when applied, so you need to work with protective equipment.
Uncured polyurethane foam is quite toxic, so all work is carried out with mandatory skin, eye and respiratory protection. - Polyurethane foam is susceptible to the negative effects of ultraviolet rays, so after applying insulation it must be covered with finishing material, for example, clapboard, plywood or drywall.
- For installation work on insulation with polyurethane foam, you must have special, expensive equipment. True, if you have the skills to work with this material, then the equipment can be rented. But in the case when this work is unfamiliar, it is better not to take risks, but to invite specialists with equipment to spray the material.
Video: spraying polyurethane foam on roof slopes from the inside
Insulation of the attic and roof is necessary for buildings located in most Russian regions, so this process should not be postponed “for later”, but thermal insulation work should be carried out at the stage of building the house. With the exception of the method of spraying polyurethane, all other insulation measures can be carried out independently, following the work technology. If you enlist the help of a friend, roof insulation can easily be completed in a few days.
There may be several reasons why you will have to insulate the roof of a country house - you purchased a house with an uninsulated roof, it was simply given to you. But one of the reasons simply “breathes” with nobility of soul - you decided to refuse the services of professional builders and insulate the roof from the inside with your own hands.
Add to your desire to work the ability to be precise in detail, and your roof insulation will go off with a bang.
One thing needs to be understood for sure - it will not be possible to do without preliminary thorough theoretical preparation.
Therefore, we present the result that, regardless of the material used, you will need to strive for (see photo):
- Roofing material is the one that takes the blow of bad weather. It can be tiles, metal tiles or, simply, slate.
- The sheathing actually refers to the system for creating the roof.
- Secondary sheathing, already for attaching the next layer.
- Waterproofing panel.
- Insulation is the main element of the insulation system.
- Vapor barrier panel.
- Lathing is often installed after the insulation to further secure it.
- Internal lining.
Materials
Among the various types of insulation that can be offered to you to solve the problem of how to insulate a roof from the inside, the following appear:
- . This is the most common type of insulation, and if you use basalt-based wool, then it can be said to be recommended. The wide variety of options offered in terms of composition and geometry will allow you to definitely find what you need, which corresponds to the pitch of the main floors of your roof. When purchasing this type of insulation, you only need to ask the seller for a certificate of sanitary safety of the material.
Often, even on inclined planes, no additional fixation of the insulation is required - the main thing is to accurately select its dimensions
- Glass wool. This material has been used very widely for quite a long time. But today, due to the emergence of more environmentally friendly materials, glass wool is gradually losing its popularity. In any case, if you decide to use glass wool for insulation, then carry out all the work in special work clothes, which you won’t mind throwing away later. Be sure to cover your face, eyes, and first of all, your hands. You should not use glass wool if allergies are constantly “registered” or sometimes “visiting” in your home.
- Polymer materials. Using polymeric materials in the form of expanded polystyrene or polystyrene boards is a very tempting solution, but be careful not to take it hastily. The point is not that these materials are flammable; the worst thing is that when burned, polymers emit a lot of smoke, which is sometimes very dangerous for the body. Therefore, the use of polymers should be classified as extreme, hopeless situations (find out also,).
- Expanded clay. This material is well known as an excellent heat insulator, but insulating a sloping or sloping roof from the inside is completely inconvenient. After all, expanded clay is a mass of small fired fractions that will simply roll down. It is possible, but somehow it has not caught on, the use of expanded clay for insulating flat roofs, although it is often used for insulating floors.
And it all ends with such “beauty”. Insulation of the roof from the inside, especially with polystyrene foam, can be done in a matter of hours
Or flat, make up almost a third of their total number. By taking a set of measures to install a thermal barrier, you can not only reduce heating costs, but also get additional living space into which the attic turns after the work is completed.
Properly carried out measures increase the service life of the entire roofing structure and create the microclimate necessary for life. The correct roof structure necessarily includes the following elements:
- roofing covered;
- rafters;
- sheathing;
- counter-lattice;
- vapor barrier;
- waterproofing;
- insulation;
- space for ventilation.
To understand the inside of a house, it is first advisable to understand the basic physical processes that occur inside the roof structure, as well as to understand the influence of the main natural forces that it has to deal with every day.
Atmospheric exposure
Any roof is subject to the influence of many climatic factors throughout the year, requiring the use of protective measures. These include:
- ambient air temperature, which fluctuates throughout the year and leads to heating or cooling of the coating;
- precipitation in the form of rain, to which the roof is especially susceptible almost all year round;
- precipitation in the form of snow, which creates additional load on the roof;
- the influence of wind, which implies reliable fixation of the coating to the structure.
Thus, the main task of the roof of a house is to create reliable protection from these influences and maintain comfortable living conditions indoors, which are characterized by a stable temperature and humidity level.
Physical processes inside the roof
The constant difference in temperature inside and outside the room leads to continuous physical processes that are of fundamental importance for understanding how to insulate the roof of a house from the inside. These include:
- heat exchange that occurs as a result of the temperature difference between the outside and inside the house and leads to heat loss through the roof, which is prevented by the located insulation;
- moisture exchange, which is a consequence of human activity (from breathing to cooking), as a result of which warm air, liquid, rises, and is prevented by located insulation and a special gap for ventilation.
The importance of physical processes in home insulation
Properly placed insulation, regardless of temperature changes, has a temperature on the outer surface that is only a few degrees higher than outside.
The use of a vapor barrier and a gap for ventilation prevents the accumulation of condensate formed after cooling the steam in the insulation, and prevents not only its damage, but also the safety of the entire roofing structure.
A clear example of how to properly insulate from the inside can be seen if you look at the roofs in houses after snow has fallen. If it is missing completely or partially, icicles hang around the perimeter, which means that the work was carried out in violation of the rules. This occurs due to increased heat exchange, as a result of which the roof of the house is heated by hot air. coming from the room, and, as a result, the snow melts.
The order of work
Before insulating the roof of a house from the inside, as in any work, it is necessary to prepare a plan, draw up an estimate and prepare the inner surface of the roof.
The plan includes carrying out the main stages, listing the necessary tools and taking measurements of the roof area. In addition to the installation of insulation, it is necessary to provide for finishing cladding, communications (for example, electricity), and installation of windows or doors. This will turn the attic into a full-fledged living space.
After the measurements are taken, an estimate is prepared and material is purchased, usually with a margin of about 15%. The choice of material and its thickness occupy a key place in the entire process, so it can be separated into a separate stage.
There is nothing difficult about doing the entire amount of work yourself. But to reduce the risk of errors, it is recommended that you carefully read the steps and tips below before insulating the roof of your house from the inside with your own hands.
The work is performed in the following order:
- surface preparation and choice of insulation;
- installation of ventilation gap and waterproofing;
- installation of insulation;
- installation of vapor barrier;
- installation of finishing coating.
Surface preparation and selection of insulator
Before work begins, the roof structure must be checked to identify damage, deterioration or other defects. Violations must be corrected, damaged elements replaced, wooden surfaces treated with impregnations or varnishes. These actions will protect the structure and eliminate the need to dismantle future layers of thermal protection for repairs.
The most common materials used for insulation today are:
- mineral wool, in rolls or mats;
- Styrofoam;
- expanded polystyrene.
They meet the basic requirements for insulation: safety, lightness, poor thermal conductivity and durability. Using glass wool indoors is not recommended. It is inconvenient to install, and microparticles negatively affect health.
The minimum insulator thickness used almost everywhere is 150 mm. In most cases this meets building code requirements.
The choice of material is influenced by the shape of the roof. For small spaces with limited surface area, laying rolls or mats can be difficult. In such a situation, there is only one way out - how to insulate the roof of the house from the inside - with foam or polyurethane foam. They are sprayed with a special pump, usually in several layers. But in this case, the help of specialists with professional equipment is necessary.
Installation of ventilation gap and waterproofing
The space for ventilation of the insulation helps prevent it from getting wet and deteriorating, which inevitably leads to a loss of protective properties. The minimum distance that should separate it from the roof surface is 20 mm. This allows excess moist air, which still passes from the room through the insulator, to be freely removed from the surface of the insulation.
The simplest waterproofing, still widely used in construction, is ordinary roofing felt. But to create more effective protection, it is advisable to use a special fabric that is vapor permeable. The best option is diffusion membranes, not ordinary membranes. In this case, only one ventilated gap is sufficient. For the usual version you need two of them:
- between the insulation and the waterproofing sheet;
- between the insulation and the roof covering.
These measures are a consequence of continuous physical processes occurring under the roof. But, for example, before insulating the roof of a house from the inside with polystyrene foam, these actions are not performed, since this material does not absorb moisture, which allows waterproofing and ventilation gaps to be neglected.
The insulation is laid with the smooth side facing the roof on specially fixed bars with an overlap of at least 100 mm, perpendicular to the rafters, after which it is fixed with staples or nails. During installation, a slight overhang is made to reduce the risk of damage during installation of the insulation. The joints are taped with tape. The waterproofing must completely cover the rafters.
Installation of insulation
The most important stage in the work process is “how to insulate the roof of a house from the inside.” Depending on the chosen material, there are subtleties of working with it. But the principles apply to all species without exception.
The width of the insulation should be 10 or 20 mm larger than the opening where it is placed. The standard rafter pitch is 600 mm, which corresponds to or is a multiple of the size of most insulation.
Fastening is done due to the dense structure of the insulation and the gap in size. But in addition, it can be secured with thin strips or cords laid between nails or self-tapping screws screwed into the rafters.
Sheets of foam plastic and cotton wool should completely fill all free space. One of the installation options is to install insulation in two layers. In this case, the second one is installed so as to completely cover the joints of the previous one.
Installation of vapor barrier
After completing the installation of the insulating material, it is necessary to secure the vapor barrier. The rough side is installed indoors, as it absorbs steam, the smooth side is installed towards the insulation. As with the installation of waterproofing, two points are important here:
- installation with the desired side facing the insulation, otherwise the effect will be completely opposite;
- fixing all joints with double-sided tape.
Fastening is done using brackets to the rafters. A sheathing is sewn over the insulation to secure future finishing. For this you can use any finishing material: plastic, wood or drywall.
To understand the individual stages of the process, how to insulate the roof of a house from the inside, the photos located at the beginning of the article and below will help with this.
Features of insulation of different buildings
Despite the fact that the basic technological process is typical for insulating different types of roofing structures, the use of each material has its own characteristics. For example, to date there is no clear majority of adherents on the question of how to insulate the roof of a house from the inside - with polystyrene foam or cotton wool. Each material has its pros and cons.
In houses with allows you to get a full-fledged living space where you can live. Eliminating the need for a warm attic will probably keep the process to a minimum if this is done with the floor first.
For most flat ones, the best option is to start insulation work from the outside first. And only if there is no effect, start working inside.
If we consider the process of how to insulate the roof of a wooden house from the inside, then its main feature is the careful treatment of surfaces with protective impregnations or varnishes, and the minimum weight of the insulation.
If the work is carried out independently, it is advisable to always follow the main rules:
- eliminate roof defects rather than mask them;
- carefully treat wooden surfaces, especially rafters;
- work only together.
Despite their simplicity, perhaps these rules will become the determining factors in the durability of the roof of a residential building.
When building a house or reconstructing it, most often its owners come to the conclusion that the roof and ceiling must be insulated in order to prevent loss of thermal energy. To insulate the roof of a wooden house from the inside, you need to choose the right thermal insulation material and install it, following the technology.
It has long been established through experience and calculations that heat losses occur through every element of a house’s structure. For example, from 20 to 30% of the heat is lost through the attic floor and roof, which means that the same part of the amount paid for its burning is wasted. Therefore, having once invested in high-quality insulation of your home, you can save on heating for all subsequent years.
It should be noted that if the house is located in a region with a mild winter climate, then many home owners prefer to insulate only the attic floor. However, thermal insulation of the roof at different times of the year can perform three functions:
— in winter it keeps the house warm;
- in summer it does not allow the attic to heat up, which means the house will be cool;
— in addition, insulation is an excellent sound insulator, so the rooms will always be quiet, even during heavy rain and with any type of roofing.
Based on these arguments, we can conclude that it is best to insulate and soundproof not only the attic floor, but also the roof itself.
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Types of insulation for roof structures
The choice of insulation must also be made with skill, taking into account the technical and operational characteristics of the material. In this case, special attention should be paid to the following:
- Low thermal conductivity.
- Increased moisture resistance.
- Low flammability.
- Environmental cleanliness.
- Durability of the material.
The materials used to insulate the roof and attic floor from the inside include:
- Mineral wool in slabs and rolls.
- Ecowool made on a cellulose basis.
- Expanded polystyrene (foam plastic).
- Penoizol and sprayed polyurethane foam.
- Expanded clay of different fractions (insulation of floors).
In addition, natural materials such as straw, slag, sawdust and dry leaves were traditionally used. Some builders still use these insulation materials today, but they require special treatment, since they are not moisture resistant, which means putrefactive processes and the formation of microflora colonies are possible in them.
All materials used for thermal insulation of the roof are relatively light in weight, so they will slightly add weight to the rafter and ceiling structure.
This table presents the main characteristics of the most popular insulation materials today:
| Material parameters | Materials | Thickness, mm | |||||||
|---|---|---|---|---|---|---|---|---|---|
| 50 | 60 | 80 | 100 | 120 | 150 | 200 | 250 | ||
| Density, kg/m³ | Mineral wool | 100-120 | |||||||
| Expanded polystyrene | 25-35 | ||||||||
| Polyurethane foam | 54-55 | ||||||||
| Thermal resistance, (m²°K)/W | Mineral wool | 1.19 | 1.43 | 1.9 | 2.38 | 2.86 | 3.57 | 4.76 | 5.95 |
| Expanded polystyrene | 1.35 | 1.62 | 2.16 | 2.7 | 3.24 | 4.05 | 5.41 | 6.76 | |
| Polyurethane foam | 1.85 | 2.22 | 2.96 | 3.7 | 4.44 | 5.56 | 7.41 | 9.26 | |
| Thermal conductivity coefficient, W/(m×°K) | Mineral wool | 0,038-0,052 | |||||||
| Expanded polystyrene | 0.037 | ||||||||
| Polyurethane foam | 0.027 | ||||||||
| Weight 1 m², kg | Mineral wool | 15.2 | 15.8 | 17.6 | 20.9 | 23.2 | 26.7 | 32.4 | 38.2 |
| Expanded polystyrene | 9.8 | 10 | 10.5 | 11 | 11.5 | 12.3 | 13.5 | 14.8 | |
| Polyurethane foam | 11.2 | 11.7 | 12.8 | 13.9 | 15 | 16.6 | 19.3 | 22 | |
Mineral wool
Mineral wool is most often used to insulate roof structures, since this material is easy to install and is well suited in its parameters for thermal insulation of attic spaces in a wooden house.
One of the most convenient materials is mineral wool.
Since this material is made from different raw materials, its characteristics and prices vary somewhat. And to choose the best option, you need to consider each of its types:
- Slag wool is produced from blast furnace slag and consists of fibers 5 ÷ 12 microns thick and 14 ÷ 16 mm long. This option is the most unsuitable for insulating an attic, so don’t be fooled by its low cost, since the insulation will have to be done again in a couple of years.
Slag wool is quite hygroscopic, which means it absorbs moisture well and, once saturated with it, it settles and loses its thermal insulation qualities. In addition, it has low heat resistance and is classified G4. This insulation can withstand temperatures of only 300–320 degrees, which is a low indicator for its use in wooden structures.
The thermal conductivity of the material is 0.48 ÷ 0.52 W/m×°K, which is much lower than that of the other two types of mineral wool. During installation, you will notice that the slag fibers are quite fragile, brittle and brittle. Therefore, it is best not to use this type of mineral wool for residential premises.
- Glass wool. This type of insulation is made from molten sand and broken glass. The thickness of the fibers is 4 ÷ 15 microns, and the length is 14 ÷ 45 mm - these parameters give the material elasticity and strength. The random arrangement of fibers promotes airiness and improves the insulating qualities of the heat insulator.
Improved modern glass wool is designed on for heating up to 460 ÷ 500 degrees, which is much higher than that of slag wool. The thermal conductivity of this type of mineral wool is 0.030 ÷ 0.048 W/m×°K.
Glass wool is widely used for insulating stone buildings; it is also suitable for the roof of a wooden house. If thermally insulated an attic version of the under-roof space, then glass wool is often used in combination with polyurethane foam.
Due to the fact that glass wool fibers are very thin, brittle and brittle, they easily penetrate the fabric and can get into the mucous membranes of the eyes or into the respiratory tract. Therefore, when starting installation work, you should protect yourself with protective equipment by wearing a suit made of thick fabric, special glasses, a respirator and gloves.
- Basalt (stone) wool is made from mountain gabbro - basalt breeds The thermal conductivity of basalt insulation is 0.032 ÷ 0.05 W/m×°K, the material can withstand temperatures up to 550 ÷ 600 degrees.
Working with stone wool is much easier, since its fibers are not so brittle and thorny, their thickness ranges from 3.5 to 5 microns, length from 3 to 5 mm. They are located chaotically and their interlacing gives the insulation good strength, so the material is quite resistant to mechanical damage.
Prices for basalt wool
basalt wool
In addition, basalt insulation is inert to chemical influences and tolerates the destructive influence of the external environment.
All types of mineral wool for insulating surfaces are produced in rolls or mats (blocks) of different sizes. Today in construction stores you can find foil material, which is more effective for insulation, since foil reflects and retains heat indoors.
The main disadvantage of all types of mineral wool is the fiber binding substance, which is often made on the basis of phenol-formaldehyde resin. It constantly releases toxic substances into the air that are dangerous to human health. Therefore, it is impossible to call any type of mineral wool absolutely environmentally friendly.
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Expanded polystyrene
Expanded polystyrene has become the most popular material for insulating houses, and all this is due to its affordability and ease of installation. But for that to the attic was thoroughly insulated, without the formation of cold bridges, it is necessary to ensure a tight fit of the heat insulator to the surfaces, which is difficult to achieve using polystyrene foam, since it does not have the proper flexibility. Therefore, it is combined with other insulation materials, including sprayed polyurethane foam.
Plates of ordinary polystyrene foam - polystyrene foam (left), and extruded
Polystyrene foam has an average thermal conductivity coefficient of 0.037 W/(m×°K), but it also depends on the density of the material, as well as its thickness.
Moisture absorption ordinary polystyrene foam is up to 2%, which significantly exceeds this parameter for extruded polystyrene foam - here the threshold is about 0.4% of the total volume of the material.
Prices for expanded polystyrene
expanded polystyrene
The most dangerous quality of expanded polystyrene is its flammability, and when ignited, the material melts, simultaneously creating thick smoke. The smoke emanating from it is extremely toxic and hazardous to health.
Therefore, when choosing this insulation, it is necessary to take into account all its positive and negative properties and protect the house as much as possible from possible emergency situations. Particular attention will need to be paid to reliable insulation of the wiring and proper installation of chimney ducts (pipes).
Polyurethane foam
Polyurethane foam is applied to roofing and ceiling structures by spraying with help special equipment. Spraying is carried out in several layers, so the coating can be quite thick. With this method of application, polyurethane foam penetrates into all cracks and crevices, so the insulating layer will be completely sealed. Hardening and expanding, the insulation acquires a high density, and its thermal conductivity is only 0.027 W/(m×°K), at moisture absorption no more than 0.2% of the total volume of material. This means that there is no loss of its thermal insulation qualities.
Sprayed polyurethane foam quickly expands and hardens, and its excess is easily cut off with a sharp knife, which adds convenience in adjusting the finished coating to the level of the rafter system for further finishing or roofing work.
By using this material, you can avoid waterproofing, wind protection and vapor barrier - it copes well with the whole range of problems, without retaining steam or allowing moisture to enter the room.
Polyurethane foam can be sprayed onto any surface: horizontal, vertical or inclined, as it has high adhesion to all building materials.
Ecowool
Ecowool is made from small particles of cellulose. Laying this material can be done in a “dry” or “wet” way.
Environmentally friendly material - ecowool
- In the first case, the insulation is scattered between the floor beams and compacted as far as possible by rolling. It will not be possible to install it on walls and roof structures using this method.
- For the “wet” installation method, special equipment is required, where the dry substance is mixed with adhesives and then distributed under pressure using a pipe onto the floors and walls.
“Wet” laying of ecowool
- Another option for insulating ecowool is to fill the space between the rafter legs, after attaching finishing material to them, for example, plasterboard or wooden lining. In this case, you need to correctly calculate the amount of material - it will depend on the height of the rafters, which will determine the thickness of the thermal insulation.
Ecowool has a number of advantages over other insulation materials, and these include the following:
- This is an environmentally friendly material that does not emit any harmful fumes into the environment.
- Ecowool is able to “preserve” surfaces, preventing fungal and putrefactive formations from developing.
- If during the operation of the house it turns out that the thickness of the insulating layer on the roof is insufficient, then it can be increased or the already laid material can be compacted.
- Installation of insulation is carried out quite quickly.
- Ecowool has a long service life without losing its original thermal insulation qualities.
- Cellulose insulation material is necessarily treated with fire retardants, therefore it has very low flammability and a tendency to self-extinguish. In addition, ecowool does not produce smoke, and even more so, it does not emit substances hazardous to the human body.
- Ecowool applied to any surface forms a seamless, hermetic coating of the required thickness.
- The insulation is a “breathable” material, so it does not retain moisture.
- The payback period for such insulation is one to three years.
The table below shows the comparative digital characteristics of two environmentally friendly materials - ecowool and expanded clay, which will be discussed below and discussed below.
| Material parameters | Expanded clay gravel | Ecowool (cellulose) |
|---|---|---|
| Thermal conductivity coefficient, W/(m°K) | 0,016-0,018 | 0,038-0,041 |
| Density, kg/m³ | 200-400 | 42-75 |
| Density of connection to the structure | Depending on the faction: | Tight fit, seals all cracks and cracks well |
| - 15-20 mm - presence of voids; | ||
| - 5-10 mm - tight fit. | ||
| Linear shrinkage | absent | |
| Vapor permeability mg/Pa×m×h | 0.3 | 0.67 |
| Chemical inertness | neutral | |
| Flammability | incombustible | G1-G2 (lowly flammable material, because it is treated with fire retardants |
| Moisture absorption,% by weight | 10-25 | 14-16 |
Expanded clay
Expanded clay is very often used to insulate the attic floor of a wooden house. Of course, the rafter system is made of expanded clay thermally insulate difficult, but pouring it between the floor beams onto previously prepared surfaces will not be difficult.
This material is made from specially prepared clay that undergoes high-temperature heat treatment. Expanded clay is produced in four fractions, starting from expanded clay sand and ending with large elements measuring 20 ÷ 30 mm.
| Fraction, mm | Bulk density, kg/m³ | Total density of material, kg/m³ | Compressive strength MPa |
|---|---|---|---|
| 1 - 4 | 400 | 800 - 1200 | 2,0 - 3,0 |
| 4 - 10 | 335 - 350 | 550 - 800 | 1,2 - 1,4 |
| 10 - 30 | 200 - 250 | 450 - 650 | 0,9 - 1,1 |
Prices for expanded clay
expanded clay
Advantages of this material:
- Ecological cleanliness. It does not cause allergic reactions and does not release toxic substances into the surrounding atmosphere.
- The insulation does not lose its original thermal insulation qualities throughout the entire period of operation.
- For insulation, you can choose a material of a suitable fraction - the density of the backfill will depend on this. The finer the fraction, the denser the backfill.
- Expanded clay is a non-flammable material, which is a very important quality for a wooden structure. This insulation is used to insulate chimney pipes from wooden floors, pouring it into a box built around them.
- Another important advantage of this material is that it is not tolerated by domestic rodents. If the house is located on a suburban area, then mice may well live in it even in the attic, and some insulation materials create quite suitable conditions for this - but not expanded clay!
You might be interested in information about what it is
Auxiliary materials
In addition to thermal insulation materials, the insulating “pie” uses waterproofing (windproof) and vapor barrier films.
- Waterproofing is necessary to protect insulation against condensation, which can be collected between the heat insulator and the roof. In addition, this material performs a windproof function, preventing cold, dust and moisture from getting from the air directly onto the insulation, as well as into the attic.
This membrane must have steam-permeable ability - excess moisture in the insulation will simply evaporate into the atmosphere.
If insulation is carried out in an already assembled structure and there are no plans to change the roofing material, under which there should be a waterproofing membrane, then for insulation you will have to use sprayed polyurethane foam - it does not require protection from the wind, and it can be sprayed onto on a reliable base made of boards or directly onto the roofing.
- When thermally insulating roof slopes, the insulation is covered with a vapor barrier film from the attic side. Vapor barrier is intended to protect thermal insulation material and wooden elements of the rafter system from moisture penetration from the inside.
As you know, excess moisture that gets on insulation and wood can lead to mold and rot, as well as an unpleasant odor, which over time will spread into living rooms.
If it is planned to equip a heated room in the attic, then the vapor barrier film must be secured under the wall finishing.
When insulating the floor, a vapor barrier is laid under the insulation, on the boards and beams of the structure, since it should retain heat in the rooms below and not allow wet vapors from them to get into the thermal insulation layer.
The protective membrane is produced in different thicknesses and can be made of foil or non-woven material. If a film with a foil surface is used, then it is mounted on the roof slopes with the reflective side towards the attic. When insulating the floor, it should be turned towards the lower room. This is done so that the heat is reflected into the attic or towards the living rooms and does not escape outside. The canvases are glued together with foil tape, which will help create the integrity and tightness of the membrane.
If you want to save money, you can use old proven methods of vapor barrier, when the cracks between the attic floor boards, as well as their joints with the beams, are well coated with a paste made from lime and clay. Such protection will not only create a high tightness of the ceiling, but will also protect the wood from pests, and will also allow the insulating layers to “breathe”.
When the lime or clay has dried well, you can proceed to insulation operations. By the way, wooden houses have been insulated with sawdust for a long time - for this they were mixed with the same clay and a little lime was added to the mixture, which gave the composition elasticity. In addition to sawdust, other natural materials were also used for insulation, which were dried and placed between the floor beams.
This method of vapor barrier and insulation is still used today, as it helps to save quite a decent amount. But all such work is very labor-intensive and requires certain knowledge, skill and time.
Those home owners who they want the work to go faster, they use modern materials.
How to calculate the required insulation thickness?
It is not enough to decide on the type of insulation based only on its environmental friendliness, ease of installation and cost. It is very important to correctly calculate the required thickness of the thermal insulation layer. This is also necessary for to create comfortable conditions in the room to avoid overpaying for excess material.
Rasche T t of the required insulation thickness is determined by special guidelines documents - SNiP 23 — 02-2003 " Thermal protection of buildings"and the Code of Rules SP 23-101-2004 "Design thermal protection of buildings" They contain formulas for calculations that take into account a very large number of parameters. But, with some acceptable simplification, we can take the following expression as a basis:
δth= (R – 0.16 – δ1/ λ1– δ2/ λ2 – δ n/ λ n) × λut
Let’s begin to understand the quantities available in the formula:
- δth– this is the desired parameter, the thickness of the layer of thermal insulation material.
- R– required table value of thermal resistance (m²×° WITH/W) insulated structure. These parameters are calculated for each region of Russia in accordance with specific climatic conditions. Such thermal resistance will ensure, with a properly designed heating system, maintaining a comfortable temperature in the room of +19°. The diagram below with a map of Russia shows the meaning R for walls, ceilings and coverings.
When calculating the insulation for the roof, the value “for coverings” is taken, for the attic floor - “for the floors”.
- δ nand λn— the thickness of the material layer and its thermal conductivity coefficient.
The formula allows you to calculate the thickness of insulation for a multilayer structure, taking into account thermal insulating properties of each layer, from 1 before n. For example, a roofing “pie” will consist of a continuous sheathing of plywood over rafters with a roofing material covering on top. Below there is a layer of insulation that has to be calculated, and then the ceiling will be lined with natural wooden lining. Thus, three layers will be taken into account: lining + plywood + roofing felt.
Important - only those outer layers that fit tightly to each other are counted. For example, flat slate can be taken into account, but wavy slate cannot. If the roof design involves a ventilated roof, then all layers located above the ventilated gap are not taken into account.
Where to get the values? Measure the thickness of each layer ( δ n) – it won't be difficult. The value of the thermal conductivity coefficient ( λ n), if it is not indicated in the technical documentation of the material, can be taken from the table below:
| Estimated thermal performance indicators of some building and thermal insulation materials | ||||||
|---|---|---|---|---|---|---|
| Material | Density of materials in dry state, kg/m3 | Calculated coefficients under various operating conditions | ||||
| ω | λ | μ | ||||
| A | B | A | B | A, B | ||
| λ - thermal conductivity coefficient (W/(m°C)); ω - coefficient of mass ratio of moisture in the material (%); ; μ - vapor permeability coefficient (mg/(m h Pa) | ||||||
| A. Polymer | ||||||
| Expanded polystyrene | 150 | 1 | 5 | 0.052 | 0.06 | 0.05 |
| Same | 100 | 2 | 10 | 0.041 | 0.052 | 0.05 |
| Same | 40 | 2 | 10 | 0.041 | 0.05 | 0.05 |
| Extruded polystyrene foam | 25 | 2 | 10 | 0.031 | 0.031 | 0.013 |
| Same | 28 | 2 | 10 | 0.031 | 0.031 | 0.013 |
| Same | 33 | 2 | 10 | 0.031 | 0.031 | 0.013 |
| Same | 35 | 2 | 10 | 0.031 | 0.031 | 0.005 |
| Same | 45 | 2 | 10 | 0.031 | 0.031 | 0.005 |
| PVC1 and PV1 foam plastic | 125 | 2 | 10 | 0.06 | 0.064 | 0.23 |
| Same | 100 or less | 2 | 10 | 0.05 | 0.052 | 0.23 |
| Polyurethane foam | 80 | 2 | 5 | 0.05 | 0.05 | 0.05 |
| Same | 60 | 2 | 5 | 0.041 | 0.041 | 0.05 |
| Same | 40 | 2 | 5 | 0.04 | 0.04 | 0.05 |
| Perlite plastic concrete | 200 | 2 | 3 | 0.052 | 0.06 | 0.008 |
| Same | 100 | 2 | 3 | 0.041 | 0.05 | 0.008 |
| Thermal insulation products made from foamed synthetic rubber "Aeroflex" | 80 | 5 | 15 | 0.04 | 0.054 | 0.003 |
| Extruded polystyrene foam "Penoplex", type 35 | 35 | 2 | 3 | 0.029 | 0.03 | 0.018 |
| Same. type 45 | 45 | 2 | 3 | 0.031 | 0.032 | 0.015 |
| B. Mineral wool, fiberglass | ||||||
| Stitched mineral wool mats | 125 | 2 | 5 | 0.064 | 0.07 | 0.3 |
| Same | 100 | 2 | 5 | 0.061 | 0.067 | 0.49 |
| Same | 75 | 2 | 5 | 0.058 | 0.064 | 0.49 |
| Mineral wool mats with synthetic binder | 225 | 2 | 5 | 0.072 | 0.082 | 0.49 |
| Same | 175 | 2 | 5 | 0.066 | 0.076 | 0.49 |
| Same | 125 | 2 | 5 | 0.064 | 0.07 | 0.49 |
| Same | 75 | 2 | 5 | 0.058 | 0.064 | 0.53 |
| Soft, semi-rigid and hard mineral wool slabs with synthetic and bitumen binders | 250 | 2 | 5 | 0.082 | 0.085 | 0.41 |
| Same | 225 | 2 | 5 | 0.079 | 0.084 | 0.41 |
| Same | 200 | 2 | 5 | 0.076 | 0.08 | 0.49 |
| Same | 150 | 2 | 5 | 0.068 | 0.073 | 0.49 |
| Same | 125 | 2 | 5 | 0.064 | 0.069 | 0.49 |
| Same | 100 | 2 | 5 | 0.06 | 0.065 | 0.56 |
| Same | 75 | 2 | 5 | 0.056 | 0.063 | 0.6 |
| Mineral wool slabs of increased rigidity with an organophosphate binder | 200 | 1 | 2 | 0.07 | 0.076 | 0.45 |
| Semi-rigid mineral wool slabs with starch binder | 200 | 2 | 5 | 0.076 | 0.08 | 0.38 |
| Same | 125 | 2 | 5 | 0.06 | 0.064 | 0.38 |
| Glass staple fiber boards with synthetic binder | 45 | 2 | 5 | 0.06 | 0.064 | 0.6 |
| Stitched glass fiber mats and strips | 150 | 2 | 5 | 0.064 | 0.07 | 0.53 |
| URSA glass staple fiber mats | 25 | 2 | 5 | 0.043 | 0.05 | 0.61 |
| Same | 17 | 2 | 5 | 0.046 | 0.053 | 0.66 |
| Same | 15 | 2 | 5 | 0.048 | 0.053 | 0.68 |
| Same | 11 | 2 | 5 | 0.05 | 0.055 | 0.7 |
| URSA glass staple fiber boards | 85 | 2 | 5 | 0.046 | 0.05 | 0.5 |
| Same | 75 | 2 | 5 | 0.042 | 0.047 | 0.5 |
| Same | 60 | 2 | 5 | 0.04 | 0.045 | 0.51 |
| Same | 45 | 2 | 5 | 0.041 | 0.045 | 0.51 |
| Same | 35 | 2 | 5 | 0.041 | 0.046 | 0.52 |
| Same | 30 | 2 | 5 | 0.042 | 0.046 | 0.52 |
| Same | 20 | 2 | 5 | 0.043 | 0.048 | 0.53 |
| Same | 17 . | 2 | 5 | 0.047 | 0.053 | 0.54 |
| Same | 15 | 2 | 5 | 0.049 | 0.055 | 0.55 |
| B. Plates from natural organic and inorganic materials | ||||||
| Wood fiber and particle boards | 1000 | 10 | 12 | 0.23 | 0.29 | 0.12 |
| Same | 800 | 10 | 12 | 0.19 | 0.23 | 0.12 |
| Same | 600 | 10 | 12 | 0.13 | 0.16 | 0.13 |
| Same | 400 | 10 | 12 | 0.11 | 0.13 | 0.19 |
| Same | 200 | 10 | 12 | 0.07 | 0.08 | 0.24 |
| Fiberboard and wood concrete slabs based on Portland cement | 500 | 10 | 15 | 0.15 | 0.19 | 0.11 |
| Same | 450 | 10 | 15 | 0.135 | 0.17 | 0.11 |
| Same | 400 | 10 | 15 | 0.13 | 0.16 | 0.26 |
| Reed slabs | 300 | 10 | 15 | 0.09 | 0.14 | 0.45 |
| Same | 200 | 10 | 15 | 0.07 | 0.09 | 0.49 |
| Peat thermal insulation slabs | 300 | 15 | 20 | 0.07 | 0.08 | 0.19 |
| Same | 200 | 15 | 20 | 0.06 | 0.064 | 0.49 |
| Gypsum slabs | 1350 | 4 | 6 | 0.5 | 0.56 | 0.098 |
| Same | 1100 | 4 | 6 | 0.35 | 0.41 | 0.11 |
| Gypsum cladding sheets (gypsum plasterboard) | 1050 | 4 | 6 | 0.34 | 0.36 | 0.075 |
| Same | 800 | 4 | 6 | 0.19 | 0.21 | 0.075 |
| G. Backfills | ||||||
| Expanded clay gravel | 600 | 2 | 3 | 0.17 | 0.19 | 0.23 |
| Same | 500 | 2 | 3 | 0.15 | 0.165 | 0.23 |
| Same | 450 | 2 | 3 | 0.14 | 0.155 | 0.235 |
| Same | 400 | 2 | 3 | 0.13 | 0.145 | 0.24 |
| Same | 350 | 2 | 3 | 0.125 | 0.14 | 0.245 |
| Same | 300 | 2 | 3 | 0.12 | 0.13 | 0.25 |
| Same | 250 | 2 | 3 | 0.11 | 0.12 | 0.26 |
| D. Wood, products made from it and other natural organic materials | ||||||
| Pine and spruce across the grain | 500 | 15 | 20 | 0.14 | 0.18 | 0.06 |
| Pine and spruce along the grain | 500 | 15 | 20 | 0.29 | 0.35 | 0.32 |
| Oak across the grain | 700 | 10 | 15 | 0.18 | 0.23 | 0.05 |
| Oak along the grain | 700 | 10 | 15 | 0.35 | 0.41 | 0.3 |
| Plywood | 600 | 10 | 13 | 0.15 | 0.18 | 0.02 |
| Cardboard facing | 1000 | 5 | 10 | 0.21 | 0.23 | 0.06 |
| Multilayer construction cardboard | 650 | 6 | 12 | 0.15 | 0.18 | 0.083 |
| E. Roofing, waterproofing, facing materials | ||||||
| - Asbestos-cement | ||||||
| Asbestos-cement flat sheets | 1800 | 2 | 3 | 0.47 | 0.52 | 0.03 |
| Same | 1600 | 2 | 3 | 0.35 | 0.41 | 0.03 |
| - Bituminous | ||||||
| Petroleum bitumens for construction and roofing | 1400 | 0 | 0 | 0.27 | 0.27 | 0.008 |
| Same | 1200 | 0 | 0 | 0.22 | 0.22 | 0.008 |
| Same | 1000 | 0 | 0 | 0.17 | 0.17 | 0.008 |
| Asphalt concrete | 2100 | 0 | 0 | 1.05 | 1.05 | 0.008 |
| Products made from expanded perlite with a bitumen binder | 400 | 1 | 2 | 0.12 | 0.13 | 0.04 |
| Same | 300 | 1 | 2 | 0.09 | 0.099 | 0.04 |
Please note that there are two values given for materials λ n– for operating modes A or B. These modes provide for specific humidity conditions - both by the region of construction and by the type of premises.
To begin with, it is necessary to determine the zone - wet, normal or dry - using the diagram map.
Then, by comparing the zone and features of the room, according to the proposed table, determine the mode, A or B, according to which select the value λ n.
| Room humidity conditions | Operating conditions, A or B, by humidity zone (according to the schematic map) | ||
|---|---|---|---|
| Dry zone | Normal zone | Wet area | |
| Dry | A | A | B |
| Normal | A | B | B |
| Damp or Wet | B | B | B |
- λut – thermal conductivity coefficient for the selected type of insulation, according to which the thickness is calculated.
Now, having written out the thickness and thermal conductivity coefficient for each layer, you can calculate the thickness of the insulation. Please note that the formula requires the thickness to be specified in meters!
To make the task easier for the interested reader, a special calculator has been placed. It provides calculations for three layers (not counting insulation). If the number of layers is less, then simply leave the extra column blank. The thickness of the layers and the final result are in millimeters.
Preface. For private houses where it is planned to use an attic floor, the issue of thermal insulation of the roof is relevant. This issue is especially acute for owners of already built houses where the attic has not been used before. In this article, we will look at how to insulate a metal roof of a house from the inside to prevent condensation. At the end of the material we will provide video instructions on this topic.
Insulating the roof of a house from the inside is an important condition for creating a comfortable microclimate. The first stage includes the independent installation of the attic into a living space and the replacement of the old roofing with metal tiles or corrugated sheets, if necessary. At the same time, condensation may form on the metal roof due to temperature changes in the autumn or spring periods of the year.
Materials for insulating the roof of a house from the inside
Insulation of the roof of a house from the inside to prevent condensation is carried out using suitable materials for thermal insulation of premises. The selected materials must ensure vapor permeability of building structures and reliable waterproofing from the outside. Moisture should not get into the thermal insulation layer, while water vapor should be removed from the attic or attic floor of the building.
Fibrous materials - basalt or mineral wool - are best suited for thermal insulation of the roof. Unlike polystyrene foam or polyurethane foam, they allow water vapor to pass through and reduce humidity in a warm room. But fiber insulation loses its properties when moistened and becomes deformed over time. When insulating a roof, it is necessary to follow the sequence of layers of the insulating “pie”.
Principles of insulating the roof of a house from the inside
On the inside, the first layer is a decorative finish - drywall, lining or plywood. Next, a ventilation gap of 2-3 cm is required to ensure air circulation. The next layer is a vapor-permeable membrane, and the insulation itself must be of sufficient thickness. For the roof, a layer of thermal insulation of at least 10 cm is laid. A vapor-permeable waterproofing film is placed on the insulation.
How to insulate a roof to prevent condensation
Thermal insulation begins with laying a waterproofing film with a slight sag perpendicular to the rafters. The joints of the material are taped with tape to eliminate gaps. After this stage, 50 mm bars are stuffed onto the rafters and a sheathing of boards is laid. In the case of insulation of a finished roof, the waterproofing film is secured using a stapler under the rafters, gluing the joints of the film with construction tape.
It is advisable to pre-treat the rafter system with an antiseptic. Thermal insulation is laid between the rafters, and slats are usually used as rough filing. If insulation mats are laid in several layers, then to create the required thickness, the joints of the top layer are completely covered by the bottom row. In other words, the bottom layer of insulation is placed offset or perpendicular to the first row.
Next, a vapor barrier film is placed, which is positioned with a smooth surface towards the insulation. The rough surface of the vapor barrier traps moisture vapor, so it is laid towards a warm room. If you put the vapor barrier film in reverse, it will not remove moisture from the thermal insulation, and condensation will form on its surface. The film is also secured using a stapler, gluing all the joints.
Next, wooden blocks or a metal profile are attached to the rafters, onto which the sheathing is mounted. If finishing of this room is not provided, then you can hem the rafters with boards treated with an antiseptic. Do not forget that insulating the roof with your own hands will save up to 25% of heat in the house, and on metal roofs it will eliminate the formation of ice and condensation in the winter.
Other ways to insulate the roof of a house
There are various methods and materials for insulating a roof from the inside, for example, spraying polyurethane foam, laying foam boards or penoplex. To use expanded polystyrene boards, no preparation is required, but the sheathing of boards is made continuous and coated with an antiseptic. Foam plastic slabs are laid closely and secured with dowels, the seams between the slabs are carefully sealed with foam.
Spraying polyurethane foam requires expensive equipment, so it is impossible to perform this procedure yourself. For this roof insulation, it is necessary to call specialists who will apply a layer of thermal insulation of the required thickness to the entire surface. Once dry, polyurethane foam forms a seamless and waterproof layer of thermal insulation with low thermal conductivity.
Video. How to insulate a roof to prevent condensation
