Insulation of the truss system in inconvenient places. The technology of laying insulation between the rafters. The main characteristics of the building material

Properly organized insulation in the house is the key to comfortable living conditions. If the main floors and wall structures do not have high heat-saving properties, then the functions of providing a favorable microclimate are shifted to insulating materials. The most effective solution to this problem is the insulation of the roof along the rafters, a photo of how this process takes place is presented in the article.

The nuances of choosing a material for insulation

The material for insulation in the rafter area is usually selected taking into account the heat-insulating potential of the structure, but this is far from the only selection criterion. The supporting structure for slopes has fundamentally important limitations in terms of additional arrangement. The main one is the weight load, so the material must be light and small in size, since the fixing devices in the case of large format panels will also provide additional mass.

As for the form factor, subject to structural compatibility, experts recommend using tiled, rolled products. An exception applies only to backfill materials that are appropriate to use on the floor of the attic or attic. It is advisable to carry out roof insulation along the rafters from the inside in thin layers, with the expectation of the possibility of a device and a protective coating. In this case, it will be better to use products with the presence of external metallized layers that provide a barrier to mechanical stress.

In addition, you should follow the general rules for choosing materials for arranging the roof and roofing system. It is important that the insulator is non-flammable and biologically stable. formed by sawn wood, in itself, without protective impregnations, it is vulnerable to the development of fungus and mold, not to mention the support of a flame. In this sense, the internal insulating coating should become a barrier to the negative factors of the possible destruction of beams and support posts.

Don't forget waterproofing

According to experts, moisturizing the insulating material by only 1% can reduce its thermal conductivity by up to 30%. In the winter season, this percentage rises and can cause destruction of the insulator structure. Therefore, the technology of roof insulation along the rafters without fail provides for the inclusion of a hydrobarrier in the insulating structure. It is desirable that the moisture-resistant shell also combines the qualities of a vapor barrier.

Hydrological insulation materials are mainly evaluated in terms of strength, abrasion resistance and fire resistance. These are mainly artificial products, so biological threats are excluded. The optimal solution may be a roofing membrane based on polypropylene or polyethylene. If you apply a modification of the film with a reinforcing fabric or mesh, then the roof insulation along the rafters can be performed without a special counter-lattice from the outside. it is recommended to lay directly on the heat insulator layer, which will reduce the amount of work and costs. This waterproofing agent directs moisture in one direction - from the surface of the insulation. Also, condensate collects on the reverse side, after which it drains or erodes. An important nuance when arranging the layers of the waterproofing agent is to lay them with the correct side to the insulation. Usually the same membranes are marked with special inscriptions indicating the front or back side.

What should be the structure of the insulating "pie"?

Configurations of thermal insulation placement in can be different depending on the characteristics of the roof, insulation requirements and rafter pattern. In any case, the outer layer will be represented by the roofing material - it can be a metal profiled sheet, bituminous tiles or slate based on asbestos concrete. This coating can also be fixed to the rafters, however, intermediate rails are most often used to make the joint secure. A kind of crate is formed, with which a heat insulator is already mated on the inside. But before that comes the outer isolation. Among the subtleties of roof insulation along the rafters, the importance of maintaining ventilated gaps should be noted. That is, 2-3 cm should remain between the conditional mineral wool slabs and the roofing for air circulation. It is this indentation that the battens of the crate will provide.

In addition, vapor barrier and wind protection may follow the thermal insulation from the outside. The presence of the last layer just depends on the type of roof. For example, modern models of shingles and ondulin take on some of the insulating functions, eliminating the need for lining additional technical layers. From the side of the attic, the technology of roof insulation along the rafters also provides for the inclusion of hydro- and vapor barrier films, which, depending on their own structure, can be covered with a crate with subsequent cladding or remain open. For all its impracticality, the second option can be justified by the fact that the owner can always assess the state of insulation during an external examination. And, on the contrary, under the lining layer, the resulting defects will be hidden, due to which dampness may appear.

How to properly insulate between rafters?

The most common insulation scheme is one in which thick slabs can be used. Moreover, the size of the segments is selected so that the width is 10-15 cm larger than the gaps between the rafters. This distance will be used as the cells of the crate, in which a heat insulator is laid according to the classical system. The width tolerance is necessary for tight integration of the insulation into free niches without gaps. As for the thickness, it is selected to decrease relative to the protrusion of the rafter legs. This condition is necessary to save space for the same waterproofing or other technological and protective coatings. Proper roof insulation along the rafters is carried out in such a way that a dense and even base is formed from the insulation material in the structure of the load-bearing beams. For this, it is necessary that the laying surface also has the correct geometry, and this again will depend on the characteristics of the roof.

The subtleties of thermal insulation under the rafters

Filling the free space between the rafter legs is a simple and practical option for warming. Thus, additional rigidity is given to the supporting structure, the structure of the insulating material placement receives the necessary holding elements, and niches are filled in which cold air can “walk”. However, this option is not always possible due to the following reasons:

• in the space between the rafters.
• Insufficient structural rigidity to accommodate additional materials.
• The use of an insulator that, in principle, cannot be laid in grooves.

In such situations, you can apply an alternative layout of the heat insulator on the back side. But even in this case, there are structural nuances of roof insulation along the rafters, which consist in the problems of removing the insulating layer beyond the level of the supporting structure. Niches between in this case are closed with solid material (plywood, chipboard, etc.), and insulation is laid on it. Thick slabs in this configuration are impractical to use, as an additional superstructure is required, which will significantly increase the load and reduce free space in the attic. But it is allowed to use thin rolled material, for fixing which, together with waterproofing, there will be enough rails and a protective reinforced film.

Insulation technology over rafters

Reverse to the previous technique, the heat insulator laying scheme is one in which the material is located not on the back side, but on the outside - between the roofing and its supporting structure. But this method also involves the observance of certain structural conditions, the main among which is the design preservation of space for the organization of roof insulation along the rafters. Laying in this case is carried out on top of the truss structure with a superstructure in the form of a crate. When preparing for installation, it is necessary to cover the load-bearing beams with sheet wood-chip panels. Lathing ribs are mounted on a flat surface, between which (a distance of about 50-60 cm) an insulator will be laid.

The upper part of the material is also covered with waterproofing and other technological coatings, depending on specific requirements. There are two options for an external closing coating. In the first case, the roof insulation over the rafters is left unfinished. That is, in relation to the back side of the roof, the same waterproofing remains open. This option is good because it leaves a free zone for air ventilation - in the place of interaction of insulators and roofing material there are surfaces that are resistant to negative humidity and biological factors. The second option involves the installation of a small-format crate with intermediate power rails, along which the roof will be laid. This scheme is good precisely for the additional mechanical and wind protection of the insulators, but in this case the ventilation effect of the under-roof space is reduced and the wood finish of the insulation remains less protected from contact with moisture.

Combined insulation scheme as the best option

In this case, complex thermal insulation of the roof structure is implemented in three directions. That is, the roof will be insulated over the rafters, between the beams and above them. It is immediately worth noting a few nuances of using this configuration, since it has many features:

This scheme is not suitable for small houses. Moreover, it is usually used in full-fledged attic rooms, where, in principle, a more solid roof structure is provided and there is enough space for the installation of complex technological elements. On the other hand, it is the combined technology of laying roof insulation along the rafters that makes it possible to turn the attic into a living space for the winter period. Even at the design stage of the roof, it is necessary to provide for the possibility of installing three levels of insulation. Technically, the installation of this design is implemented under the following conditions:

• Two crates are organized from the inside and outside in relation to the truss structure. That is, beams for rafter legs are initially selected with large sizes, preferably with metal reinforcing plates.
• It is planned to turn on the supporting vertical racks to hold not only the truss structure, but also the insulation. To evenly distribute the load of the supporting area at the level of roof insulation, metal sheets or chipboard panels with grooves for fixing racks are mounted along the rafters from the inside.
• As each new layer of insulation is laid with panels closing the next crate, it is necessary to make technological holes for the future passage of ventilation and chimney pipes. In a completely closed formed insulation structure, this operation at all levels will be difficult to perform.

Fastening methods and insulators - what to consider?

Basically, two methods of installing thermal insulation materials are used: adhesive and mechanical (using hardware). Each of them has its own nuances of application, so they should be considered in more detail:

• Adhesive fastening method. If you plan to perform roof insulation along the rafters with your own hands, this method will be preferable. To implement it, it is enough to clean the laying surface in the form of the same plywood sheet or the back side of the roof, apply the adhesive mixture and fix the insulator. This technique is used for both roll and tile insulation, but in both cases it is necessary to choose the right composition. For self-laying, beginners are advised to use ready-made dry mixes. More experienced roofers use two-component products that can be further modified to improve certain performance. For both cases, it is recommended to use products from Ceresit, Soudabond and Insta.
• Mounting with mechanical fasteners. The complexity of this method lies in the fact that the rafter system is not the most successful base for installing hardware. By the way, the unsuccessful introduction of a large-format dowel into a weak beam can cause future decay of its structure or the spread of cracks. How to properly insulate the roof along the rafters in order to avoid such phenomena? Firstly, large-sized nails, anchors and dowels should be abandoned in principle. The emphasis is not on force capture (as a rule, heaters have a small mass and do not require rigid fixation), but on holding in the desired position. To do this, it is enough to use umbrella thin dowels. In the case of rolled materials, you can completely limit yourself to mounting brackets by installing them with a construction stapler. Secondly, the installation points, together with the fasteners, are pre-treated with antiseptic and other bioprotective solutions for wood, which will prevent the processes of decay, mold and fungus inside the structure.

Features of roof insulation along the rafters with mineral wool

This is the most famous material for thermal insulation. Despite certain disadvantages, such as extremely low protection from moisture, mineral wool is readily used in roofing. This material can perform both partial and complete insulation of the roof structure. It is advisable to use plates with a thickness of 20 cm (minimum), if we are talking about a region with a cold winter. If there are structural restrictions on the thickness, then the thickness is reduced to 10-15 cm. By the way, the same rules apply when the roof is insulated along the rafters with foam, but with one fundamental difference. Foam plastic, with all its advantages as a heat insulator, has a drawback associated with unsatisfactory soundproofing qualities. Therefore, in addition to auxiliary technical layers of insulation, it may be necessary to additionally lay noise-reducing material.

As for installation, it is necessary to note the nuances of observing safety precautions with such insulation of the roof along the rafters. How to properly install mineral wool? Only in tight gloves, a respirator and goggles, since this material releases toxic substances. Technically, laying is carried out according to the general scheme on the crate with a mandatory coating with a waterproofing agent, but it is also recommended to additionally apply thin retaining rails along the central parts of the slab placement.

Features of the use of foam insulation

This is a rather specific material in terms of thermal insulation of the roof, it is rarely used as such, but with proper installation, such a move is possible. Foam insulation is usually understood as polyurethane foam, the qualities of which determine the non-standard nature of this kind of insulation. To begin with, it is worth considering how it is beneficial to insulate the roof along the rafters based on a foam composition? This is the best option in terms of design. Spraying polyurethane foam allows you to lay the material in different configurations, regardless of the complexity of the site, the foam will take any shape. In addition, it is the lightest heat insulator, so you do not have to be afraid of excessive weighting of the truss system.

However, there are severe restrictions on the use of polyurethane foam on the roof. This material supports combustion (at least slowly smolders, also releasing toxic substances), does not combine with metal sheet roofing (excessive condensation and minimization of the ventilation gap) and cannot be used in places where exposure to high temperatures is expected (if the roof is heated strongly from the sun, destruction will occur material). But does this mean that it is worth refusing to insulate the roof along the rafters with polyurethane foam? Not at all, since its negative properties are not of particular importance when puncturing the so-called cold bridges. That is, the foam insulator can be applied zonally as an addition to the main heaters.

Conclusion

When deciding on the choice of roof insulation technique, it will not be superfluous to turn to special offers from thermal insulation manufacturers. Large firms meet the needs of the consumer, trying to facilitate installation tasks when using their products. For example, the insulation of the roof along the rafters with Penoplex is distinguished by the use of a tongue-and-groove locking edge, which completely eliminates the issue of choosing a fastener technique and minimizes gaps at the joints. In turn, the Knauf company offers special solutions for pitched roofs. This is a roll material that is easy to cut, takes the desired shape of the laying and does not require further protection with a waterproofing agent, since its structure contains Aqua Statik proprietary water-repellent impregnation. No less interesting options for heaters for a variety of operating conditions are also offered by the manufacturers Izover, TechnoNIKOL, Ursa, etc.

The main heat loss of a building occurs through the "enclosures": walls, windows, floor and roof.

Since the roof is in direct contact with the environment, it is constantly influenced by changing weather conditions. The roof must meet the most important requirement: to maintain indoor comfort and minimize heat loss. The task is quite difficult, given the fact that the external temperature in some latitudes can range from minus 50 to plus 40-45 degrees.

How to properly organize insulation?

The very word "insulation" does not mean that the gable roof will warm up. It speaks only of taking measures to ensure that this design retains heat.

Particular attention should be paid to insulation work in the case when it is planned to use the attic as an additional living space.

The attic has a number of distinctive (from the rest of the interior) features: it is limited to surfaces with different structures:

• attic flooring;
• roof slopes;
• gable walls.

The insulation of each of these parts has its own characteristics, which should be taken into account for the quality of work.

How to choose the right material for the insulation of a gable roof?

There are a number of basic requirements, compliance with which is evidence of the high quality of the insulation:

1. The material must be waterproof. If it is hygroscopic, over time a large amount of moisture will accumulate in it, which will lead to an increase in thermal conductivity and the loss of other important properties.
2. An indispensable quality is the ability to maintain a geometric shape for a long time. If this requirement is not met, the material eventually slides to the lower part of the roof, and the upper part remains unprotected from the penetration of cold.
3. The insulation must retain its quality characteristics for quite a long time, so that for a long time there is no need for a major overhaul of the roof.
4. The next indispensable requirement is environmental friendliness and safety. This item is especially relevant for the roofs of residential buildings, although the roofs of industrial and utility buildings must also correspond to it. When insulating, it is unacceptable to use materials that emit toxic compounds or are dangerous from the point of view of environmental cleanliness.
5. Resistant to sudden temperature fluctuations. In cold regions, special attention should be paid to the frost resistance of the insulation.
6. Fire safety - the material should not be flammable.

The main methods of insulating a gable roof

When insulating a gable roof, three main methods are used:

• Laying insulation material between the rafters.
• Rafter laying.
• Laying insulation under the rafters.
• The first method is most often used. It is the simplest and most efficient.

During installation, you must strictly follow the rules. Otherwise, not only the insulation, but the entire roof will not last long.

If installed incorrectly, the material can absorb moisture and transfer it to the rafter system in contact with it. The result is rotting of the foundation of the entire roof.

Common Mistakes

When installing heat-insulating material, mistakes are often made, which result in a reduction in the service life and loss of quality characteristics of the insulation. The most frequent of them:

• The waterproofing layer is not installed.
• Waterproofing installed, but not fixed. The consequence is the displacement of the insulation layer and the formation of cold gaps.
• In many cases, when carrying out work, they forget about the need for a ventilation gap. As a result of the lack of ventilation, a large amount of condensate is formed, which penetrates into the insulation and eventually causes the rafter system to rot.
• Another common mistake is the lack of vapor barrier.

Work order

When carrying out work on insulation, it is necessary to follow a certain sequence. The process is not particularly difficult.

1. First of all, you need to measure the distance between the rafters.

2. Then the insulation material is measured with a slight gap.

3. A layer of waterproofing is installed

4. The insulation is laid between the rafters. Thanks to the gaps left, the material fits snugly against the truss structure and holds itself in place.

5. The insulation is laid from the bottom up. It is necessary to try to make installation with a minimum number of seams.

6. During the laying process, care must be taken to ensure that there are no gaps, as they will lead to significant heat loss.

7. Between the layer of insulation and waterproofing, there should be free space - at least 2 cm. When carrying out work, one circumstance must be taken into account: heaters expand by 10-30% over time.

8. We must remember the need for ventilation gaps for free air circulation in the under-roof space, thanks to which it will be possible to avoid the formation of condensate and subsequent damage to the insulation material and the truss system.

9. When cutting the insulation, do not leave too much clearance. This may cause the material to sag.

10. If it was not possible to avoid sagging, it is necessary to compact the sheet, which will prevent the appearance of so-called "cold bridges".

11. The entire surface is covered with a layer of vapor barrier.

12. The heat-insulating material is fixed with wooden bars or planks across the rafters - a counter-lattice. In the case of an attic, the planks will serve as the basis for interior decoration.

The main types of heaters

URSA (URSA)- This is one of the modern insulating materials that fully meets the requirements.

Its basis is spatula fiber, processed according to the proprietary technology of URSASpannfilz.

The insulation has such a high level of geometric stability that it does not need to be updated or repaired for the entire period of operation.

URSA is available as 1200 x 4200 mm mats with a thickness of 150 mm. The material is rolled into dense rolls and sealed in a film.

Before use, the rolls are opened and allowed to straighten. It takes only a few minutes to achieve normal dimensions and restore thickness.

After the mat must be cut. If the pitch between the rafters is 60 cm (standard size), the mat should be cut lengthwise into two parts.

In the case of a different distance between the rafters, the mat is cut across into separate plates, the length of which should be approximately 30 mm longer than the size of the rafter step.

After that, the plates are placed between the rafters (while they need to be slightly compressed). Due to the high degree of elasticity of the material, the mats stay in place on their own, and there is no need for additional fastening

Installation of this heater is so simple that even one person can carry it out. URSA is also suitable for broken gable roofs.

• glass wool- the material has been used for a very long time and still has not lost its popularity.

However, it should be noted that this insulation has a number of serious drawbacks, as a result of which many builders do not recommend using it for thermal insulation of a gable roof:

• glass wool perfectly absorbs moisture and loses its quality characteristics in a short time;
• it is easily deformable and loses its geometric shape, as a result of which, when it is used, a significant complication of the roofing cake is necessary to prevent slipping;
• material does not meet environmental safety requirements.

• Mineral wool- a very popular material for insulation. It is obtained as a result of special processing of basalt rocks.

They are subjected to extremely high temperatures, after which the resulting mass is pressed and shaped into rigid plates. As a result of the described actions, a chaotic interlacing of fibers into a very dense micronetwork occurs. Thanks to this structure, the plates do not deform, do not absorb water and moisture, are resistant to temperature fluctuations and the effects of adverse environmental factors,

In addition, mineral wool does not emit toxic substances and does not burn.

• Spatula heaters- this material is non-hygroscopic and easy to install. There are several types that differ from each other in the degree of density. Therefore, it can be used for internal insulation and external thermal insulation.

For maximum heat retention, a material with a high density of fibers is used. It is perfect for double pitched roofs. Due to its weight, the insulation fits snugly against the slopes, which helps prevent slipping. The material based on spatula fibers meets the requirements of environmental friendliness.

How to properly insulate a gable roof

• After the rafter legs are correctly installed, on the inside of the rafters (starting from the lower end), it is necessary to mount the inner crate, while the step should be from 15 to 30 cm. It will be the basis for attaching the insulation layer (roll or plates).

• From the outside, the insulation is laid in 1-2 layers. It is necessary to monitor the tight fit of the joints to the rafters. There should be no through holes in the insulation.
• After laying the insulation, it must be covered with waterproofing (on the outside of the rafters). The waterproofing material is unwound from a roll and nailed to the rafters with a slight sag using staples.

Care must be taken not to confuse the upper and lower sides of the membrane.

• The top has waterproofing qualities and does not allow moisture to pass through, and the lower part must allow moisture and evaporation to pass through. Layers are made with a 15 cm overlap.

• During installation, it is necessary to ensure that the insulation and the membrane do not touch. There should be a distance of 2 to 5 cm between them. In the upper part, at the ridge, a small ventilation hole must be drilled along its entire length. 10 cm membranes should not be connected. This technique creates additional traction, due to which the air flow will blow moisture out of the under-roof space.
• After laying the membrane on the rafters, it is necessary to take care of an additional ventilation cavity. For this purpose, along the rafters (right on them) a bar measuring 25 x50, 50 x 50 mm is stuffed. It can be made from pieces of 1.5-2 m.
• Across the rafters, over the bars, a crate is stuffed (the step should be 15-30 cm).

Both the crate and the bar are best treated with an antiseptic solution.

• The created gap for ventilation removes condensate and moisture from both the membrane and the truss system. An appropriate roofing material is mounted on the crate: corrugated sheet, metal tile, etc.
• A vapor barrier is attached to the crate from the inside. This avoids the ingress of fumes from the interior into the insulation layer.

Instead of a crate of boards, you can use a nylon rope nailed to the rafters (on the inside).

Another way: pull the vapor barrier over the rafters, and fill the crate on top.

After completing the installation of the vapor barrier, proceed to the next step:

• The rafters are stuffed with slats (20 x 30 mm), and on them - the inner lining: plywood, lining, blockhouse, etc.
• In the lower part of the roof, the material should hang down and be located in such a way that moisture and the resulting condensate flow into the gutter and do not reach the insulation.

FINDINGS:

• Roof insulation is necessary to keep the house warm.
• Work should be treated especially carefully when planning an attic device.
• Warming is carried out in three ways: the material is laid between the rafters, on the rafters or under the rafters.
• The material for thermal insulation must meet several basic requirements: be waterproof, retain its shape and not emit toxic substances.
• Universal insulation is URSA.
• Very often, mineral wool and spatula heaters are also used.
• When carrying out work, it is necessary to adhere to a certain sequence of actions.

How to properly insulate the roof, see the video clip.

Planning to turn the attic into a living room? In this case, roof insulation and truss construction cannot be dispensed with. They can be carried out both in the process of the initial construction of the house, and later - during reconstruction or repair.

Below we consider how to properly insulate the roof along the rafters and which of the existing technological processes to choose. A well-thought-out plan will save you unnecessary time and money.

Features of the process of thermal insulation of the roof

Expert opinion

Konstantin Alexandrovich

In order to live in the attic year-round, it is required to insulate not only the upper part of the roof, but also the slopes, side ceilings and junctions with load-bearing walls. All necessary calculations and layer thicknesses are described in SNiP II-3-79. The most suitable option is a material with a thermal conductivity of not more than 0.04 W / m C.

When choosing a material, you should pay attention to its crease. Good insulation does not sag under its own weight. This parameter is important in the arrangement of the roof, because. the rafter system is tilted, and the load on the insulation will be constant. A quickly removed sheet slides to the base after a few years, due to which a “bare”, non-insulated zone will appear at the ridge. Heat will be lost through it, losses can reach up to 40%. The best choice is material marked "for pitched roofs."

Do-it-yourself roof insulation

The heat-shielding properties of the roof are as important as the walls and floor. The comfortable temperature inside the room, as well as the service life of the insulation and the roof itself, depend on the correct execution of the technological process. Despite all the complexity, it is possible to perform insulation on your own, without the involvement of professionals.

The choice of insulation

The most popular material for pitched roofs is foam. It fully meets all the requirements: fire safety, reduced hygroscopicity, ease of use and a fairly low cost. When installing polystyrene foam to the rafters, there is a special system. The material placed between the rafters can be fixed in several ways. The installation process starts from the bottom and ends at the ridge. This sequence is dictated by the rules for laying foam (from bottom to top).

An alternative to foam will be mineral wool insulation. However, many experts agree that its technical characteristics are significantly inferior to the previous version. In addition, it is somewhat more expensive than foam.

For the correct selection of insulation, it is necessary to know all the stages of the work, the properties and technical characteristics of all materials. The construction market offers a wide range of:

• polyurethane foam spraying technology. This is one of the innovations in the field of insulation;
• polystyrene foam or polystyrene;
• several types of foam insulation;
• mineral wool;
• ecowool.

Before buying, you should familiarize yourself with the properties of each of them, calculate the required amount and choose the most suitable one.

The design of the roofing "pie" pitched roof

This technology of warming is made on rafters. Before starting, it is worth studying in detail all the stages of work. This will help to avoid serious mistakes that lead to damage to the truss system.

The second most popular material for insulating the roof of a private house is mineral wool. It has increased fire safety, incombustibility and relatively low cost. The downside is increased hygroscopicity. Mineral wool has the ability to absorb moisture and accumulate it inside itself. This leads to a significant decrease in thermal insulation and, over time, provokes the processes of damage and decay in the rafter system. Therefore, when working with mineral wool, special attention is paid to layers of vapor and waterproofing. An important role is played by ventilation and free air circulation in the under-roof space.

All work is done from the attic side. You can choose any time, both during the construction period and later, during the repair. In the second case, it is initially worth checking the condition of the truss system, eliminating, if necessary, all rotten elements. The next step is the processing of wooden rafters with an antiseptic and fire retardant.

In layers, the “pie” of roof insulation looks like this:

• top finish;
• waterproofing. The hydrobarrier, as a rule, is made of a dense film or a special superdiffusion membrane;
• selected insulation material;
• a layer of vapor barrier film;
• interior decoration (if necessary).

Adequate air exchange plays an important role in the long life of the roof. To ensure this process, layers are created between:

• a layer of membrane and a top coat of the roof;
• insulation and waterproofing layer;
• vapor barrier and decorative finishing.

Air movement is provided in all directions: inflow and removal. Free circulation is achieved due to a special design - products. They are located on the roof overhang and at the very top of the roof, under the ridge.

Instructions for step-by-step insulation on rafters

The stages of work are quite simple and logically sequential:

1. First, the distance between the rafters is measured. According to these dimensions, sheets of insulation are cut. 1.5 cm is added to each on all sides. Such calculations make it possible to achieve the installation of a heater by surprise, gaps and gaps between the plates are excluded. If the work is carried out in conjunction with the construction of the roof, then they can be significantly simplified. To do this, it is necessary to design the distance in the truss system for a certain width of the insulation.
   
2. The next mandatory step is the installation of a waterproofing layer. The membrane film should, as it were, envelop all the rafters, excluding gaps and cracks. Fastening is carried out using a construction stapler. The waterproofing film must be placed under the roof overhang, thus achieving the outflow of accumulated moisture. With this installation method, it will not be possible to achieve the required air clearance. The best choice for this case would be a special (superdiffusion membrane).
3. When working with non-membrane film, the procedure changes. First, nails are stuffed into the rafters with an interval of 10 cm. Their height is 3-5 cm from the waterproofing. A strong synthetic thread or twine is stretched between the driven nails. After that, all nails are hammered to the end. Such manipulations will help create the necessary air gap. In the case of fixing the insulation with a cord (and not with sheathing), a similar row of nails is also placed along the outer edge of the rafters.
   
4. Installation of insulation boards. If the choice is on mineral wool, then when placed in the crate, it must be slightly compressed. In this way, maximum packing density is achieved. When using foam sheets, it is important to carefully measure their size and not allow free placement between the rafters. For high-quality retention of heat inside the room, it is necessary to create two layers of insulation. With the inevitable trimming of the material and the placement of non-solid sheets, it is important to stagger the seams. Those. the joints of the lower plates must not coincide with the joints of the upper ones. The exit of the heat insulator beyond the plane of the rafter legs is unacceptable. If the width of the rafters is narrower than two layers of insulation, then a beam is additionally stuffed to them.
5. Methods for fixing sheets of thermal insulation: stretched cord or wooden crate. For the first option, nails should be stuffed into the rafters in advance, without knocking them out to the end. After placing the mineral wool or foam plastic, stretch the twine between the nails and knock it out to the end. The crate for fastening also serves for mounting the inner lining. It is made of wooden slats placed at a distance of 30-40 cm from each other. The vapor barrier with this method is fixed in advance. The film is placed on the inner surface of the crate using a stapler. Due to the thickness of the wooden slats, the necessary air gap and circulation are achieved.
   
6. At the last stage, when working with a vapor barrier, maximum attention is paid to the tightness of this layer. When placing, overlaps of at least 10 cm are necessarily created, all joints are glued with adhesive tape in several layers. Particular attention is paid to the junction of the chimney and the roof, as well as the space near the walls.
7. Finishing is done on request. It can consist of particle board or plasterboard.

Despite all the laboriousness of the process of roof insulation, it is available for execution even to a novice master. A well-made roofing "pie" allows you to use the attic as a living space even in the cold season. One of the important parameters of comfortable living is the correct use of hydro and vapor barrier.

Eventually

For a long and high-quality service of a freshly erected roof, you should take care of its proper insulation in advance. For these works, a huge selection of insulating materials is presented on the market, several work techniques are used. A thorough analysis of the current state of the roof and the desired results allows you to choose a suitable and profitable option.

Video on roof insulation with mineral wool

The problem of high heat loss, and as a result, financial costs, will be solved by laying insulation between the rafters.

As you know, warm air is much lighter and rises, so economic and thrifty homeowners are concerned about insulating the roof of their home.

Materials used for roof insulation

The modern building materials market offers a lot of base options for creating decent roof insulation. The most common is considered to be glass wool and mineral (basalt) wool.

Glass wool is represented by the thinnest glass threads, and therefore requires care when working to avoid getting small particles on the skin, eyes and respiratory system.

Glass wool is quite elastic, durable, resistant to fire. The material is publicly available and has a low cost, which makes its use very practical and popular.

Mineral wool occupies a leading position among other materials. It is presented in the form of gabbro-basalt fibers bonded with various combined substances.

Mineral wool is a good insulation between the rafters. It is more flexible than glass wool and safer, but still requires the necessary precautions.

Mineral wool has the following characteristics:

• fire-resistant and not subject to the combustion process;
• the elasticity of mineral wool allows you to easily place the plates in the required space;
• the constant shape of the plates makes it possible to avoid gaps between the insulation and the rafters;
• retains heat well, has high thermal insulation performance;
• ease of fastening.

An important difference of the presented material is the affordable price.

Despite many positive characteristics, basalt wool has a high hygroscopicity.

Over time, the material absorbs a large amount of moisture and gets wet, losing its thermal insulation properties.

Preparing the roof for insulation

If you follow the technology, then the insulated roof - several layers replacing each other.

When insulating the roof, it is necessary to follow the sequence, because each constituent element performs the function assigned to it and must be located in the allotted place.

In addition, in the process of roof insulation, it is important to ensure competent ventilation, vapor barrier and waterproofing.

Roof insulation by laying material between the rafters is the most popular, despite the difficulties in installing the heat-insulating layer.

In this case, the insulation layer is laid along the height of the rafters and fastened at a distance between them.

In this regard, it is better if the size of the prepared insulation sheets is 20–30 mm larger than the distance between the rafters.

If this is not possible, then it will be necessary to create an additional fastener that will keep the insulation from falling and sagging.

It can be a fishing line stretched and fixed with nails hammered into the lower edge of the rafter legs.

You should think about the waterproofing layer in advance. If the roofing material has not yet been laid, then a waterproofing super-diffuse film is spread on the rafters, designed in such a way that it does not allow moisture to pass through from the outside, and steam in the opposite direction.

To fix the film start from the cornice overhang, moving up. The canvases are laid with a 10 - 15 cm overlap, while fastening the joints with adhesive tape.

The membrane is attached to the surface of the rafters with construction staples or wide-head nails to prevent damage.

It is very important not to stretch the waterproofing membrane: when the temperature drops, the material shrinks, which can lead to damage to it, and consequently to damage to the entire structure. The membrane should be laid with a sag.

As a rule, roof insulation is carried out before installation of roofing material.

However, there are situations when it becomes necessary to insulate the roof from the inside: lack of a heat insulator, insufficient amount of insulation laid earlier, or when insulating an old house.

In this case, the installation of insulation is possible, but will not be so reliable and durable.

The waterproofing film is laid indoors without dismantling the roofing material.

To this end, it is necessary to wrap the rafters with a film and lay it in the space between them, and then follow the standard scheme.

However, this design does not protect the rafters from the weather, which can lead to premature wear.

To do this, a wooden crate of slats is stuffed on top of the waterproofing layer, fixed with self-tapping screws.

It is good if holes for fastening are pre-prepared in the rails, which will avoid damage to the waterproofing film.

The technology of laying insulation between the rafters

The next step is the actual installation of the insulation. Accordingly, the work is carried out indoors. In advance, the mineral wool must be freed from packaging so that the plates take their shape.

After that, the material is cut to the desired dimensions, adding 2-3 cm for laying the material "by surprise".

You can cut the insulation with a construction knife, while not forgetting about safety measures.

When working, use a respirator, goggles, gloves, tight clothing to prevent small particles from getting into the eyes, respiratory tract or on the skin.

When the insulation is prepared, proceed to its installation. Sliced ​​slabs are placed between the rafters, while the edges of the cut slabs are slightly bent.

You should press on the central part of the laid canvas, due to which it will “spring” - this will lead to straightening of the edges.

A vapor barrier film is attached over the fixed mineral wool elements, which protects the heat insulator from vapors coming from the living quarters.

The membrane is laid perpendicular to the rafters, with an overlap of 10 - 15 cm, glued with adhesive tape and fixed with building brackets to the rafters.

To create the necessary layer for ventilation, which contributes to the evaporation of moisture, a wooden grate is stuffed over the vapor barrier layer. The most commonly used slats are 2.5 cm thick.

The final stage of insulation is the installation of finishing material. It can be attached directly to the surface of the rafters using special screws or to a crate made of wooden slats.

Thus, the roof insulation is completed: the materials are located in the designated places and perform the function assigned to them.

It is important to comply with the necessary conditions, the procedure and the technology for using materials, then roof insulation will not cause you much trouble.

In addition, the building is in need of repair. If necessary, you can dismantle the finishing material, the crate and the vapor barrier layer, make repairs, and then mount everything back.

Heat rises - this is an indisputable fact. If nothing is done, then it will all leave the building and you can say goodbye to the comfort in the house, or you will have to go broke on heating.

Therefore, roof insulation along the rafters is not an idle topic for everyone who cares about their home and their family.

Is it worth it to insulate the roof in a particular house?

Before you start choosing a material and laying a heat insulator, you need to decide whether insulation is required or you can and should do without it.

The main thing here is to make a fundamental decision - will the attic be used as a “not insulated” pantry for various small things, or is it still planned to make a living room there.

The roof should be insulated along the rafters only in the second case, when arranging the attic. The snow lying on the roof must be insulated from the attic heat, otherwise it will begin to thaw and turn into ice, followed by damage to the roofing materials.

But in a situation with a non-residential attic, it is necessary to insulate the ceiling between the living rooms in the house and the under-roof space. Otherwise, it will cease to perform the functions assigned to it, and, plus, corrosion processes may begin on the rafters.

Material selection

There are many options for insulating the roof between the rafters on the domestic market of thermal insulation materials:

• Styrofoam (extruded polystyrene foam) - excellent water absorption and thermal conductivity, but due to its rigidity, it is of little use for roofs.
• Polyurethane foam - thermal conductivity is comparable to the first material, but the water absorption is greater (you cannot do without arranging a high-quality waterproofing layer).
• Penoizol is a urea-formaldehyde foam in the form of mounting foam (after foaming it fills all the holes and cracks, but under the influence of water and steam it quickly loses all its thermal insulation qualities and is also easily destroyed even with light pressure).
• Mineral wool (from basalt, glass or slag) - fibers obtained by extracting from mineral raw materials or industrial waste.

The main problem of all polymer heat insulators is their combustibility.

Styrofoam tolerates moisture well, but it is cruel in work and it will leave gaps at the rafters. Therefore, it is the last option, stone (basalt) mineral wool, having the best thermal conductivity among all mineral wool, that is the most optimal choice for roof insulation along rafters.

The main thing is to qualitatively perform its vapor barrier so that moisture cannot get close to it. And it is easy to work with it, and with proper installation, any gaps for drafts are excluded.

The technology of proper inter-rafter insulation

Upon completion of laying the mineral wool between the stacks, a “layer cake” should be obtained, in which layers go out sequentially from the attic:

1. Decor (plasterboard or lining).
2. Ventilation gap.
3. Vapor barrier (cotton wool must be protected from steam).
4. Minvata.
5. A waterproofing gasket that releases steam to the outside, but does not allow water to enter the mineral wool.
6. Second ventilation gap
7. Roof material.

It is most convenient to carry out work on roof insulation even at the stage of arranging the roof during the construction of the house, otherwise you will have to remove the roofing material later.

Work outside

After the installation of the system is completed, even before the installation of the roof itself, waterproofing should be laid from a special superdiffusion membrane. The main thing is not to confuse her sides. Outside, it spreads with a moisture-proof layer. Laying is done from the cornice upwards, while the canvases overlap by 10-15 cm and all joints will need to be glued with construction tape. To attach the film to the rafters, it is most convenient to use a construction stapler or you will have to work with a hammer. The main thing is that the nails are galvanized.

It is not recommended to stretch the waterproofing film on the rafters. With a decrease in temperature, it will begin to shrink a little and simply be damaged at the fasteners, and the webs may also disperse with the formation of gaps.

Next, a crate is stuffed over the superdiffusion membrane. It will require wooden slats of 2.5-5 cm, depending on the planned space for ventilation and the type of roofing material. Galvanized self-tapping screws are quite suitable as fasteners. At the end, the roofing is installed on top of the crate.

If the insulation is performed in the attic with the roof already laid and if the waterproofing was missed during its installation, then it will be necessary to remove the roofing material and lay the film. Otherwise, the roofing insulation will get wet and lose all its thermal insulation properties.

If the membranes are laid from the inside and wrap the rafters with them, then they will simply begin to rot from an excess of moisture.

The considered technology involves the use of sheet roofing materials (slate, metal tiles, corrugated board). To insulate a soft roof along the rafters, you will need to nail moisture-resistant plywood on top of the crate, and the finish coating is already attached to it.

Works inside

After the arrangement of the roof, the laying of mineral wool begins between the rafters inside the attic. The mineral wool must be unpacked, let it lie down a little and straighten out, and then cut into pieces equal to the distance between the rafters with the addition of 3-4 cm.

The material should be pressed between the rafters with little effort to fill the entire space.

A vapor barrier film is stuffed over the mineral wool to the rafters, using the same technology as outside. Then again a gap is made for ventilation, on the crate of which the interior decoration of the ceiling and walls of the attic is mounted.

It can be drywall for further finishing or lining for painting.

findings

In general, roof insulation along the rafters is a rather laborious process, but with the right execution, it will be possible to live in the attic even in winter. The main thing is not to forget about the mandatory vapor barrier.

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