To understand how to insulate the roof of a house, you need to know how it is structured, the features of its design and operation. For flat roofs alone, the domestic company TechnoNikol offers almost forty schemes of technical solutions. There are fewer such solutions for a pitched roof, but there are some here too different variants. And if you consider that this company is not the only one that produces roofing materials, and each other has its own established schemes, then a non-professional may get confused. But regardless of the technical nuances and characteristics of the materials, the principles of roof insulation are general.
Principles of insulation
There are two broad classes of roof construction: flat and pitched (or attic). And if we talk about functions, then there are also two of them: protection against atmospheric phenomena and thermal insulation.
In a flat roof, both functions are combined in one “pie”, which has the following arrangement of layers: ceiling, thermal insulation, roofing.
Insulation of a pitched roof can have three fundamentally different options:
cold attic with insulated ceiling;
exploited or a residential attic with an insulated roof:
combined roof with a warm contour of a dedicated attic.
But regardless of the design and location of the thermal insulation, all schemes have a common fundamental rule on how to properly insulate the roof of a house - on the side of the warm room, the insulation must be covered with a continuous and unbroken layer of vapor barrier materials. And the design itself must ensure the weathering of moisture from the insulation.
There are two main reasons for protecting insulation from getting wet - loss of thermal insulation properties and increase in the weight of the roofing cake. And if the loss of thermal insulation properties, apart from discomfort, does not threaten anything serious, then an excessive increase in the load on the supporting structure of the roof can lead to its collapse. In addition, vapor barrier in a pitched roof protects wooden structural elements from rotting and loss of load-bearing properties.
Insulation of a flat roof
The technology for insulating a flat roof depends on the floor materials and operating conditions.
Insulation of a flat wooden roof
Typically, flat wooden roofs are considered a “sign” of a frame house. This is precisely the scope of application that is indicated even in the “proprietary” description of roofing systems of companies producing thermal and waterproofing materials TechnoNikol. But even in brick houses, a wooden flat roof is not uncommon, since with a relatively light weight of the structure, it is possible to ensure sufficient rigidity and strength of the roof of a low-rise building.
The insulation scheme looks like this:
Base. Moisture-resistant OSB board (class 3 or 4).
Vapor barrier film. Spread the strips overlapping by 15-20 cm on the long side and on the short side (when increasing in length). Along the perimeter, the vapor barrier should rise to the parapet and adjacent surfaces by the same 15-20 cm. Polymer-bitumen vapor barrier films are attached to the base using glue or telescopic fasteners (together with thermal insulation). Polypropylene or polyethylene film can be spread without attaching to the base, fixing it around the perimeter to the walls of adjacent surfaces using self-adhesive vapor-tight tape.
Insulation for the roof of a house. Three types of materials can be used for thermal insulation of a flat roof: stone wool mats, extruded polystyrene foam, and rigid polyisocyanurate foam boards.
Roof covering.
Perhaps the most common example of a flat insulated roof over a wooden floor is a terrace with access from the second floor. But in this case, the design of the roofing pie is closer in structure to the insulated ceiling of a cold attic.
On our website you can find contacts of construction companies that offer roof repair services. You can communicate directly with representatives by visiting the “Low-Rise Country” exhibition of houses.
As a roof covering for flat roofs, roll waterproofing materials are used, which make it possible to create a continuous and unbroken top layer. But, as with the insulation of a pitched roof, the waterproofing layer must be “breathable”. There are two main options for installing a breathable flat roof:
application polymer membranes with high mechanical strength and resistance to direct exposure to ultraviolet radiation;
two-layer bitumen coating– fused rolled insulation on top, a substrate with ventilated channels on the bottom (for example, Uniflex Vent).
The advantage of a wooden flat roof is that a slight slope is created due to the position of the floor beams. And it is needed even on a flat roof to drain precipitation into the drain.
Insulation of a flat roof over a concrete floor
This type of insulated flat roof accounts for the most options for constructing a roofing pie.
To begin with, there are unexploited and exploited flat roofs. Moreover, “exploitation” can be of a completely different nature - from a terrace as a recreation area to the arrangement of a so-called “green roof”.
If we do not take into account the different options for roofing, then on a concrete floor the same sequence of layers is used as on a wooden one, except for one nuance - the organization of a slope to drain precipitation into the external or internal system gutter And here several solutions can be used:
device for covering screeds with a slope;
device by concrete base bulk slope-forming layer of expanded clay, separated from the insulated roofing pie by a reinforced screed;
installation of a bulk slope-forming layer of expanded clay over a layer of extruded polystyrene foam or mineral wool, followed by laying screed and roofing;
installation of a slope-forming layer from special slabs or thermal insulation mats, in which one surface is located in relation to the other with a slope.
Insulation of a pitched roof with a cold attic
Insulation of a pitched roof with a cold attic occurs along the ceiling. And depending on the flooring material, the patterns differ slightly.
Insulation of the concrete floor of the attic
The layout of the layers is partially reminiscent of the insulation of the floor of the first floor:
A layer of vapor barrier is spread over the ceiling (overlapping strips, with gluing of joints and abutments to the enclosing surfaces).
Install logs (lathing) for laying the heat-insulating layer.
Lay thermal insulation. Typically, non-combustible materials are used as thermal insulation for the roof of a house - stone wool mats or loose expanded clay.
Lay a layer of waterproofing with high vapor permeability. According to the standard, laying a strip 1 m wide from the line of intersection of the ceiling with the external walls is required. When insulating the attic floor of a private house, the procedure is simpler - lay a waterproofing membrane over the entire area.
A spacer strip is attached along the joists (needed for a ventilated gap).
Installing the attic floor.
Insulation of the wooden floor of a cold attic
The insulation scheme for a wooden floor differs fundamentally in the location of the vapor barrier. The vapor-proof film is not attached to the floor beams from above, but is hemmed from below.
Video description
How to properly make hydro- and vapor barrier insulation of a cold attic floor, see the following video:
If you do the opposite, then water vapor from warm air will penetrate into the pores of the wood, but will not be able to erode - there is a vapor-proof barrier on top. This will lead to wetness of the wooden elements of the supporting structure, and no treatment with antiseptics will save the wood from waterlogging and rotting.
The scheme for insulating the wooden floor of a cold attic looks like this:
On the side of the room there is a vapor barrier, on top of which there is lathing for decorative finishing of the ceiling. Vapor barrier can be of several types: simple film, with an anti-condensation surface, with a reflective (reflective) surface. In addition to protecting the thermal insulation from getting wet, it protects the room from insulation particles getting inside.
Thermal insulation between beams is stone wool mats or expanded clay.
A layer of waterproofing superdiffusion membrane.
Distance bar.
Attic flooring.
Insulation of pitched roofs
This type of insulation of the roof of a house is used for arranging attics or if engineering equipment is installed in the attic (for example, a hydraulic accumulator, expansion tank, fan coil or ventilation system recuperator).
The standard roof insulation technology has the following scheme:
On the rafter legs, a waterproofing superdiffusion membrane is stuffed from bottom to top in overlapping strips. Vertical joints when extending the membrane in length must overlap and be on the rafters. Subsequently, the lower edge of the waterproofing is glued to the drip line (to drain condensate into the gutter).
On top of the waterproofing, a counter batten is nailed to the rafters, which provides a ventilation gap between the membrane and the roofing. To seal the fastening line, an elastic tape can be laid between the lath and the waterproofing.
Mineral wool mats are laid between the rafters.
A continuous layer of vapor barrier is attached to the inside of the rafter legs. If it has an anti-condensation or reflective surface, then it is turned towards the attic.
Place a spacer strip on top of the vapor barrier. It is necessary for the “correct” functioning of the anti-condensation or reflective layer. The second purpose of the slats is lathing for the interior lining of the attic.
A combined insulation scheme is used when highlighting “ warm circuit» attics. The principle of this scheme is to insulate the vertical fences inside the attic and only that part of the roof that is adjacent to the attic.
Video description
The following video is a demonstration of insulating an attic roof with two layers of stone wool:
Conclusion
Roof insulation is perhaps the most complex look among all thermal insulation works on enclosing surfaces. In a variety of schemes for different types designs and materials can only be understood by a professional. And the choice of insulation and the calculation of the thickness of the thermal insulation layer depend on the design. In addition, it is necessary to provide and arrange your own roof and attic ventilation system, without which the insulation will get wet and lose its properties, and the wooden structural elements will begin to rot.
The roof is the first line of defense of a house, taking on all the blows of the elements, be it rain, hail, snow, wind or scorching sun. The effectiveness of its protective functions largely depends on the quality of insulation. We are talking about both direct heat loss, which accounts for up to 25% of all heat loss in the house, and about protecting roofing structures from exposure to external factors. Therefore, during construction or renovation, it is very important to properly perform insulation and remember that there are no secondary elements in the design of the roofing pie.
Cold and warm roofing: design features
First of all, it is necessary to distinguish between these two types of roofs. Cold means with a cold attic and insulation of the house along the attic floor. Warm - with a residential attic and insulation between the rafters. Why is it important? The fact is that, regardless of the type of roofing, cold and warm roofs have different designs.
Inexpensive but durable waterproofing films are most often used as part of a cold roof. Their main task is to ensure effective removal of condensate and prevent it from entering the attic, including the insulated ceiling.
The procedure for insulating a cold roof
- When installing a cold roof, the waterproofing film is laid perpendicular to the rafters. The membrane rolls are rolled out with an overlap of 100-150 mm and the joints are glued with construction tape.
- Then the film is secured to the rafters with counter-lattice bars. After this, a sheathing is mounted across the rafters, onto which the roofing covering is attached.
- For flexible tiles, a so-called “solid” sheathing is made, i.e. lay solid sheets of OSB or other similar material on the counter beams.
- The ventilation gap between the film and the roofing can be minimal, especially since the attic itself is a ventilated room.
- When the roof is ready, insulate the attic floor, not forgetting to install a vapor barrier under the insulation layer.
Construction and installation of a warm roof
Work on arranging a warm roof, as in the case of a cold one, also begins with laying waterproofing. At the same time, it is important to remember that a simple film can no longer be used, since the insulation will be located directly under it, which must “breathe”, releasing excess moisture into the atmosphere. Otherwise, the thermal insulation may become damp and will not perform its function well.
In order for the insulation to evaporate excess moisture, the waterproofing layer must be vapor permeable. Therefore, instead of films, hydro-windproof membranes are used, for example, ISOVER Vetranet (AM). Without allowing water to flow down and wet the insulation and rafters, it allows water vapor to pass from the bottom up. Another advantage of Vetranet (AM) is that it can act as a temporary shelter, protecting the structure from rain and allowing the installation of the roof covering to be postponed for up to two months.
Some homeowners are trying to save money and, instead of membranes, use cheap micro-perforated films, which, according to their manufacturers, also combine waterproofing properties with vapor permeability. However, not everyone knows that this is only validly observed as long as the film is still hanging. As soon as it comes into contact with any base from below, a leak immediately appears in this place. And in a warm roof, the waterproofing lies on a layer of insulation.
Important! Unlike a cold roof, in a warm roof the ventilation gap between the roofing covering and the waterproofing must be sufficient for all excess moisture to effectively evaporate, carried away by air currents ascending from the eaves to the ridge.
Calculation of counter beam for ventilation gap
- With a standard slope slope (25-40º), the height of the counter beam should be at least 50 mm, for steep slopes (more than 45º) - at least 40 mm. The flatter the slope, the worse the traction under the roof, so for slopes of 5-25º you need a counterbeam with a height of at least 60 mm, and for a slope of less than 5º - 100 mm.
- The length of the slope also matters. All given values are valid for slopes up to 10 m long. If it is longer, then you need to increase the height of the ventilation gap by 10% or additionally install aeration pipes. More details on the calculation methodology can be found in SP 17.13330.2011 “Roofs”.
The ventilation gap should not be interrupted so that the air flows ascending from the eaves to the ridge do not encounter obstacles, and the water rolling down the membrane does not accumulate anywhere. Therefore, no crossbars should be placed across the beams of the counter-lattice.
Do-it-yourself roof insulation (step by step)
- The insulation is installed after installing the hydro-windproof membrane. It is mounted from below, from the attic side, between the rafters and from the bottom up. With multi-layer insulation, all layers of thermal insulation material are laid with the seams staggered. If the thickness of the required layer of thermal insulation exceeds the height of the rafters, then they are built up with bars of the required thickness, which are stuffed perpendicularly.
- Mounted on the rafters below vapor barrier film. It is attached to the rafters with overlapping horizontal stripes, with the blades overlapping by 100-150 mm, using a construction stapler or nails with a wide head. Joints and places where the film is attached are sealed using vapor barrier tape or reinforced construction tape.
The disadvantage of using conventional film as a vapor barrier is the numerous tears and punctures during its installation. Even an experienced builder will not notice everything; as a result, the insulation may get wet in places. Therefore, for high-quality vapor barrier, we recommend using specialized membranes, for example, ISOVER Paranet (B).
This is a durable two-layer vapor barrier, which is installed with the smooth side facing the insulation and reliably protects the roofing cake from fumes. The rough inner surface allows you to retain drops of condensation that form in heated rooms in winter.
Choice of insulation
This is a responsible task. Thermal insulation should be lightweight, easy to install and at the same time effective. Of the modern varieties of mineral wool, quartz wool best meets these conditions. The thermal conductivity of its light grades is 0.037-0.041 W/(m*°C), which practically corresponds to the performance of polyurethane foam. At the same time, quartz wool is 1.5-2 times lighter in weight than stone wool with similar characteristics.
Thanks to thin (3.5-5 microns) and long (25-30 cm) fibers, it is characterized by high strength and elasticity, therefore it fills the entire space between the rafters without gaps or cracks, preventing the formation of cold bridges.
To insulate the roof and attic floors, it is advisable to use cotton wool in rolls, since it is more convenient to install it in solid pieces along the entire length of the rafters and a compressed roll holds 1.5-2 times more material than in a package with compressible slabs. As a result, the cost of transporting insulation is reduced by 1.5-2 times.
As a rule, insulating the roof of a house with your own hands for permanent residence involves laying mineral wool in two layers, since one layer (maximum 150 mm) is not enough for the harsh Russian winters. In this case, for the first (outer) layer you can use ordinary quartz wool (for example, ISOVER Warm Roof with increased sound insulation and moisture resistance), and for the second - ISOVER Pitched Roof Comfort with a craft vapor barrier coating. The insulation is installed between the rafters with the backing down, after which it is glued to them with ISOVER Paranet adhesive tape.
Mineral wool does not rot or decompose from exposure to moisture
Is it possible to insulate a cold roof?
You won’t be able to simply “add up the insulation” of a cold roof in an old house: the covering will have to be completely removed. This is due to two reasons: the need to organize a ventilation gap of sufficient height and to replace the waterproofing film with a vapor-permeable membrane. There is no way to do this from the attic side. True, if the house has “history,” then the roofing usually still needs to be replaced.
If it was built relatively recently, then completely covering the roof means incurring serious costs. Therefore, it is better to make a decision in advance about what will be located above the top floor. It’s even better to play it safe: even if you decide to make a cold roof, you can use a hydro-windproof membrane instead of a film and choose a thicker counterbeam. It is possible to equip the attic even after a few years, the main thing is that it is possible in principle.
So, all decisions have been made, materials have been selected, which means you can start working. The main thing to remember: there are no trifles in the roofing business! A properly installed roof will reliably protect the house from cold, heat and bad weather and will serve faithfully for many years.
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. Excessive 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 different types- a 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.
- On rafter system is laid . 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.
- Further, if the roof slopes are covered with soft roofing material, it is necessary to lay plywood on top of the counter slats. In the case when slate or other hard material is used sheet material, instead of plywood, a sheathing is installed, 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 Lately is becoming increasingly popular and is suitable for both conventional 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 enough long term service, which is about 30 years.
- The material does not emit toxic substances human body substances and 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 For insulation with polyurethane foam, it is necessary to 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, therefore, this process should not be postponed “for later”, but thermal insulation work should be carried out at the stage of building a 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.
The roof is a complex structure that has a whole range of different functions, including heat exchange between the attic room and the external environment. Regardless of whether the attic is used for living or not, roof insulation must be carried out even in regions located in the south of our country.
Expert opinion
Konstantin Alexandrovich
Ask a question to an expertThe article will give reasons for insulation, consider aspects of choosing insulation for the roofing area and give advice on how to independently arrange a warm and durable roof.
The need for roof insulation
The presence of an attic room is an important factor in regulation temperature regime inside the home. Even if this area is not heated, the attic will act as a buffer between the ceiling of the upper floor of the building and the external environment, and therefore perform a thermal insulation function. 
To reduce the level of heat loss through the ceiling of rooms located at the top of the building, the floors of the attic rooms require insulation. At the same time, they continue to participate in the heat exchange procedure, so in winter the temperature in the attic differs from the street temperature to a greater extent. An uninsulated roof will cause drops of condensation to form on the inner surface of the roof in cold weather. Because of this, the wooden rafters begin to rot, and puddles may form on the floor. In addition, inside a private house or dacha, there is a violation of the temperature regime for at least a year, since the lack of thermal insulation in the roof area makes the attic room not only cold in winter, but also excessively hot in summer.
Do-it-yourself roof insulation
In order to insulate a roof, it is not necessary to involve specialists whose services are expensive. You can do this work yourself. The process begins with the selection of materials that will be needed for the work, and a work plan is created and detailed diagram. Each roof has two parts:
- external - roof;
- internal, including a system of rafters and ceilings.
The entire range of insulation work is carried out only after a thorough examination of these components. If any defects are found, repairs must be made. After this, excess moisture is removed and preventive measures are taken to combat fungi and mold.
To prevent wooden structural elements from being affected by fungus or mold, they are carefully treated with antiseptic compounds. Protecting structural parts made of metal from rust consists of treating them with compounds that prevent the formation of corrosion.
Materials used for roof insulation
Below is a list of the main characteristics of materials used for thermal insulation of the roof space:
- The density level is a parameter that determines the degree of porosity of the material, and therefore its thermal conductivity. Low level density means the presence of a large number of pores in the material, which negatively affects the thermal conductivity of the insulation and positively affects its ability to retain heat.
- The thermal conductivity coefficient expresses the ability of an insulator to transfer heat. The intensity of thermal conductivity is inversely related to the porosity of the material and the degree of its humidity. If the insulator has absorbed moisture, the insulating properties will be reduced or lost altogether.
- In order to reduce the value of this coefficient and reduce the significance of the moisture factor, insulation materials with a fibrous structure are treated with various impregnations that impart hydrophobic properties. In other words, they don't absorb moisture as much. If you are going to purchase mineral wool-based insulation, you should choose materials treated with water-repellent agents.
In addition to the characteristics already discussed, great importance is attached to the degree of environmental friendliness of thermal insulation. The material should not release any toxins into the environment during operation. 
The heat insulator flammability standards are contained in documents SNiP 02/23/2003 “Thermal protection of buildings” and SP 4.13130.2013 “Fire protection systems”. They also indicate acceptable standards regarding the degree of smoke formation and its toxicity. It is important to check the purchased material for the presence of appropriate certificates, which the seller must present to the buyer upon request.
For thermal insulation of roofs, insulation materials belonging to various groups can be used. Their differences lie in physical parameters. To make it easier for you to make an informed choice for specific operating conditions, below these groups of materials will be discussed in more detail.
The classic option is mineral wool
List of main advantages if mineral wool is installed correctly:
- high level of isolation from extraneous sounds;
- lack of flammability;
- low specific gravity of the material;
- a small percentage of material shrinkage;
- service life is 25 years or more.
If the insulation you bought turns out to be too thin, you can do a multi-layer installation with the obligatory bandaging (displacement) of the joints by 20 centimeters. The fewer seams are formed on the surface of the insulating flooring, the fewer cold bridges will appear in the future.
Highly environmentally friendly material - basalt wool
Insulating materials based on natural basalt are a separate species mineral wool. Varieties designed for roof insulation have a thickness of 5 to 15 centimeters. They have a porous structure, due to which they retain heat well, weakly absorb moisture and do not sag over time, which makes it a leader on the market. 
Bulk thermal insulation: expanded clay, sawdust, foam granules
Insulation materials that are applied using the backfill method have not lost their popularity today, being slightly inferior to mineral wool slabs due to their skillful promotion on the market. The main advantage of such materials is the ability to be mixed with almost any material and incorporated into the structure. Popular varieties are:
- sawdust;
- expanded clay granules;
- vermiculite;
- foam balls;
- ecowool.
One of the interesting insulation materials for use in the attic area is vremiculite. It is a natural stone mined by quarrying. Its properties are similar to those of expanded clay. In addition, it is able to absorb foreign odors and destroy them, which is an additional advantage for the attic.
Polystyrene foam is a material that requires careful handling.
Expanded polystyrene, also called polystyrene foam, is foamed polyethylene granules pressed into sheets of varying densities, the thickness of which can be up to 20 centimeters.
It is strictly not recommended to use this material to insulate the roof area of a residential building, especially if it is built of wood. The slightest error in the execution of work will lead to negative impact styrene on human health. The respiratory system and circulatory system may be affected, headaches and other signs of malfunction may appear. nervous system. Workers in factories that pack foam plastic into blocks often complain of coughing. In addition, foam-based materials release toxic substances when melted. 
Extruded polystyrene foam also has positive qualities that are of increased value when installing inversion roofs. These include moisture resistance.
For insulation, sandwich panels can also be used, which are sheets of mineral wool placed between two layers of thin steel or OSB boards. This design prevents the penetration of water vapor into the thickness of the insulation and allows you to extend its service life.
Ecowool - excellent vapor permeability
The degree of heat capacity of ecowool is often compared with that of mineral wool. Other indicators can also be considered good: 
- High level of fire safety of the material. Special treatment makes it very resistant to fire. Combustion is not supported under the influence of an open flame. Ecowool can be used to make charcoal that smolders but does not burn.
- Ecowool actively supports air exchange with the external environment and is able to withstand the maximum level of air humidity without losing the effectiveness of thermal insulation. Its installation does not require specialized vapor barrier membranes, but they are still preferable to polyethylene.
- Significant biological stability. Ecowool does not mold, and harmful insects do not grow in it. This is facilitated by processing the material with borax.
- Good sound insulation properties of the material.
Polyurethane foam: a combination of durability and practicality
The main advantage of polyurethane foam is the long service life of the heat insulator. The cells of the material have a complex molecular structure, closed to moisture and oxygen. The correct technique for applying the material is to spray it, rather than pour it or lay it down. 
The material must not be exposed to direct sunlight. Ultraviolet radiation destroys the structure of polyurethane foam, leaving only a loose substrate.
The installation process of the material is extremely simple. Interior The roof is first covered with a low-density layer of polyurethane foam, 20-25 centimeters thick. A layer of greater density is applied on top of it, but thinner, only a few millimeters.
There is an important aspect regarding the safety of polyurethane foam. Ventilation of an attic insulated with this material must be organized in such a way that its particles cannot penetrate into the premises where people live permanently. Depending on a large number of different factors (temperature, humidity, etc.), the walls of its cells undergo constant expansion, which is why the insulation fails much earlier than the manufacturer promises. In conditions room temperature the cells actively lose gas, becoming gradually less effective for thermal insulation.
Conclusion
Among the works related to thermal insulation of certain surfaces, insulation of the roof of a country house can be considered the most difficult, in comparison with work on insulating the floor or walls. Various design options have their own numerous schemes for carrying out insulation measures, which only specialists can understand. Based on the diagram, the choice of insulation is made, as well as the calculation of the required level of thickness of the insulation layer. 
In addition, it is important to properly arrange the ventilation system in the space under the roof, which will avoid problems with the insulation getting wet and reducing its basic properties.
Video about proper roof insulation
When building a private house, you should pay attention not only to the thermal protection of walls and floors, but also to the insulation of roof structures. The temperature and humidity conditions of the room, and even the service life of the structures, depend on the correctness of roof insulation measures. You can do the installation of thermal insulation material yourself.
The need for insulation
Distribution of heat loss in a private houseEveryone knows from school physics that heated air rises. If there is no thermal insulation, nothing prevents him from leaving the building. Because of this phenomenon, a large amount of heat loss occurs through the roof or attic floors. Lack of necessary protection from cold and loss of warm air can lead to the following problems:
- lowering the room temperature;
- increased heating costs in winter;
- condensation on the inner surface of the roof;
- the appearance of mold or mildew on roof elements;
- destruction or damage load-bearing structures, and bringing the house into disrepair.
The insulation of roof structures, as well as the insulation of walls and ceilings during the construction of multi-apartment residential buildings, is necessarily checked by state or private expertise at the design stage.
Thermal insulation of a private cottage depends entirely on the future owner; no one checks its availability and wise choice, but this does not make it lose its importance.
Insulation methods Do-it-yourself roof insulation largely depends on the roof structure. There are two types of roofs: flat and pitched. Most often, flat roofs are used for the construction multi-storey buildings
- , but it can be used in the construction of a private cottage. Flat roofs can be constructed in two ways:
- ordinary roofing;
inversion roofing.
- In inversion, the order of layers has been changed. This technology is used when arranging a serviceable roof. The following can be used as insulation material in both cases:
- Styrofoam;
- extruded polystyrene foam;
- mineral wool (in slabs);
expanded clay
The latter is quite cheap, but has lower thermal protection characteristics. In most cases, roof insulation is applied from the outside. This allows you to simplify the installation process and make protection from the cold that is competent from a thermal engineering point of view. Layout of insulation between rafters
It is necessary to remember the strength of the material; additional measures will also be required to protect the insulation from mechanical damage. When building a private house, the option with a pitched roof is most often used. It allows you to equip an attic or attic and has a more attractive appearance. Roof insulation wooden house
- or any other can be done in several ways:
- laying material between the rafters (the most common);
- laying insulation on top of the rafters;
fastening from the bottom of the rafters.
Material selection
- Insulation of the roof of a wooden house or building made of other materials is carried out using the following materials:
- mineral wool (more details can be found in the article “Insulation of the roof from the inside with mineral wool”);
- polystyrene foam (for more details, see the article “Roof insulation with foam plastic technology”);
polyurethane foam (spray foam).
- Rarely used materials include:
- expanded clay;
sawdust. Scheme of roof insulation with mineral wool
In general, materials for thermal protection measures must meet the requirements:
- safety, absence of harmful effects on humans;
- environmental friendliness;
- low weight to prevent excessive loads on the rafter system;
- resistance to creasing and sagging, sufficient strength and rigidity;
- sound insulation characteristics (especially important when using metal roofing);
- fire resistance (especially important for wooden construction);
- if possible, good vapor permeability, which will provide additional ventilation of the room;
- good thermal protection characteristics.
One of the most important characteristics of a material is its thermal conductivity. This value must be indicated by the manufacturer. The lower the value, the smaller the thickness of the insulation will be needed. If you are not short on money, it is better to choose materials such as mineral wool or expanded polystyrene. The values of their thermal conductivity depend on the manufacturer and are in the range of 0.03-0.04 W/(m2*ᵒC).
Thickness calculation
Table with the main characteristics of materials It is important not only to choose the right material for insulation, but also to correctly calculate its thickness. Insufficient will lead to condensation, and excessive indicates waste of money.
You can select the value “by eye” based on general recommendations, for example, regardless of the type of roof (pitched or flat), for insulation with mineral wool or expanded polystyrene, a layer thickness of 150-200 mm will be required. It is best to perform a full thermal calculation that takes into account modern requirements
comfort and allows you to find the ideal balance of cost and quality. For a specialist, performing such a calculation will not be difficult. A person who is far from construction can use examples of calculations or the Teremok program, which is freely available and quite simple and understandable.
Competent calculations at the design stage are aimed at saving the budget and ensuring the reliability of thermal protection.
Their implementation will not take much time, but will allow you to avoid cost overruns during construction and additional costs for repairs during operation.
The process of insulating a flat roof Thermal calculation mansard roof
- Depending on the type of roof, the insulation technology will be different. For flat roofs, the following layer order is usually followed:
- load-bearing structure (most often reinforced concrete covering);
- thermal insulation material;
- cement-sand screed (for not durable materials reinforced);
- waterproofing carpet, which serves as a finishing coating.
If absolutely necessary, you can carry out work from inside the room, but this method has several disadvantages:
- reducing the height of the room;
- transfer of dew point inside the structure;
- inconvenience of work.
Thermal protection of pitched roofs
Before properly insulating the roof of a house, you need to understand the procedure for carrying out the work. pitched roof in the vast majority of cases, insulation is between the rafters. Insulating a roof from the inside with your own hands is a completely feasible task. It is important to follow the correct order of laying materials from bottom to top:
- interior decoration;
- bottom sheathing;
- vapor barrier;
- rafters with insulation between them;
- waterproofing;
- wind protection;
- sheathing;
- roofing material.
When the thickness of the insulation is greater than the height of the rafters, counter-battens are installed. It is better to use modern diffusion membranes as wind protection and waterproofing.
Proper insulation, regardless of the type of roof, requires a careful approach. To avoid problems during operation, it is necessary to select the correct thickness of the insulation, choose a reliable manufacturer and follow the installation technology. Fulfillment of these conditions will allow the roof to last a long time and help maintain normal temperature and humidity conditions in the building.