Insulation of a residential attic. How can you insulate the attic from the inside. The choice of material. The better to insulate the attic floor in a private house

Most often, when building a house, an attic room is immediately thought of as residential. At the same time, the question arises of how to insulate the attic so that it is a usable area not only in summer, but also in winter. But sometimes it also happens that the idea to arrange a room in it arises already in the process of building an attic. If the roof slopes are located at an angle of 35 ÷ 45 degrees, and raised high enough, the design of the attic for a cozy room suggests itself.

Of course, in this case, you will have to turn to specialists who are professionally engaged in such a technological process of insulation and have the necessary equipment for this. But on the other hand, you can free yourself from all further worries about insulating the slopes and get such a thermal insulation layer that does not require waterproofing, since it will tightly cover the inner surface of the roof and rafters by itself.

Materials for self-insulation of the attic

If the waterproofing film is laid on the rafters, then the following insulation materials can be used for further work:

Mineral wool is the most popular insulation, which, in terms of parameters, is excellent for thermal insulation of a wooden roof system and roof slopes. Mineral wool is heat and moisture resistant, has a very low thermal conductivity, is durable, elastic, which is very convenient when performing installation work. In addition, all types of mineral wool are excellent noise absorbers and soundproofing. Sometimes, in order to enhance the insulating effect, sprayed polyurethane foam is also used in combination with mineral wool. This option is especially in demand in the conditions of the northern regions with a cold climate.

Mineral wool is produced in different forms - in mats and rolls. It can also be foil coated. A material with a similar layer is laid with foil inside the room so that the accumulated heat is reflected back.

Expanded polystyrene () is a well-known insulation, affordable and easy to install. However, practice shows that often this material alone is not enough to make the attic room really warm, since it does not adhere sufficiently to the roof surface.

It can also be used in combination with sprayed insulation. In addition, ordinary foamed polystyrene (not extruded) is not resistant to fire, and emits toxic substances during combustion - this fact must also be taken into account when choosing one or another insulation.

Polyurethane foam can be sprayed in several layers, and have, in principle, any desired thickness that is required for high-quality insulation of the attic. When solidified, it acquires a sufficiently high density, it is easily leveled along the rafters by cutting off excess foam. The sprayed material will penetrate into all the cracks and close them from the penetration of drafts and precipitation. Moreover, it also gives the roof structure and roofing additional resistance to mechanical stress.

The sprayed material rapidly increases in volume and solidifies. Using it, you can do not only without waterproofing, but also without vapor barrier, since this material in the frozen state easily copes with these problems - it does not delay the exit for steam, but at the same time - does not let moisture in.

Sprayed polyurethane foam can be used not only for insulating the slopes and walls of the attic, but also for its floors. It is also sprayed between the wooden parts of the structure, in this case between the floor beams.

Ecowool is a shredded material that is made from natural cellulose with appropriate additives. They are good at insulating the gaps between the floor beams. Shredded ecowool is not very suitable for wall insulation, as it does not have such a pronounced adhesive property as polyurethane. However, there is a technology of wet adhesive spraying, but it necessarily requires sophisticated professional equipment.

In order to create the required thickness of the insulation layer, galvanized metal profile trusses are arranged across the floor beams. The space between them will be filled with ecowool. This process is carried out with the help of special equipment - a compression unit through a special pipe carries out pneumatic transfer of the material under pressure from the hopper or mixer to the place of its installation.

TOP 10 best attic insulation

	Name	Rating
The best basalt insulation
#1	Hotrock Smart	⭐ 99 / 100
#2	rockwool	⭐ 98 / 100
The best fiberglass insulation
#1	Ursa Geo	⭐ 99 / 100
#2	Isover Warm House	⭐ 98 / 100
The best foam insulation
#1	Knauf Therm House	⭐ 99 / 100
#2	PSB S 15-O	⭐ 98 / 100
The best polystyrene foam insulation
#1	TechnoNicole XPS Technoplex	⭐ 99 / 100
#2	Penoplex Comfort	⭐ 98 / 100
The best polyester fiber insulation
#1	Shelter EcoStroy ShES standard	⭐ 99 / 100
#2	Shelter EcoStroy ShES arctic	⭐ 98 / 100 1 - voice

Video: attic insulation using a set of materials ROCKWOOL

Prices for popular types of heaters

insulation

How to calculate the required thickness of the insulation yourself

It is important not only to choose the right insulation material - you need to know how thick it should be in order to fully ensure the thermal insulation of the attic room. And at the same time, this is also necessary from the point of view of not overpaying for excessively thick insulation, which, in fact, will not give any advantages and will only become an unnecessary waste of material.

The calculation method is determined by special documents - SNiP 23 — 02-2003 and SP 23 - 101-2004 "Design thermal protection of buildings". Its main principle is that the total value of the thermal resistance of a building structure should not be lower than the design indicators established for various climatic regions. These values of temperature resistance (R) are summarized in special tables, but it is easier to use a map diagram.

Please note that the diagram map shows separate values \u200b\u200bfor walls, floors and coatings for each region - any one has all these elements. The roof, walls and floor of the attic are always multilayer structures, and one of the layers will be a heater.

The total value of heat transfer resistance for a structure of n layers is:

R = R1 + R2 + ... Rn

The resistance to heat transfer is equal to:

Rn = δn/ λ n

where δ n is the thermal conductivity of the material, λ n is its thickness (in meters).

Since the insulation is considered as one of the layers, its thickness can be calculated using the formula:

δut= (R – 0.16 – δ1/ λ1– δ2/ λ2 – δ n/ λ n) × λut

The scheme of the structure of the gable wall, roof or attic floor is not a secret for the owner. Measuring the thickness of each of their layers is also not the most difficult task. It remains to find the thermal conductivity coefficients for each of the materials. To do this, you can use the attached table:

Estimated thermal performance of some building and thermal insulation materials
Material	Density of materials in dry state	Design coefficients under various operating conditions
		ω		λ		μ
		BUT	B	BUT	B	A, B
λ - coefficient of thermal conductivity (W / (m ° C)); ω - coefficient of mass ratio of moisture in the material (%); μ - vapor permeability coefficient (mg/(m h Pa)
A. Polymer
Styrofoam	150	1	5	0.052	0.06	0.05
Same	100	2	10	0.041	0.052	0.05
Same	40	2	10	0.041	0.05	0.05
Extruded polystyrene foam	25 ÷45	2	10	0.031	0.031	0.013
Polyfoam PVC1 and PV1	125	2	10	0.06	0.064	0.23
Same	100 or less	2	10	0.05	0.052	0.23
polyurethane foam	80	2	5	0.05	0.05	0.05
Same	60	2	5	0.041	0.041	0.05
Same	40	2	5	0.04	0.04	0.05
Thermal insulation products made of foamed synthetic rubber Aeroflex	80	5	15	0.04	0.054	0.003
Extruded polystyrene foam "Penoplex", type 35	35	2	3	0.029	0.03	0.018
Same. type 45	45	2	3	0.031	0.032	0.015
B. Mineral wool, fiberglass
Mineral wool mats	125	2	5	0.064	0.07	0.3
Same	100	2	5	0.061	0.067	0.49
Same	75	2	5	0.058	0.064	0.49
Mineral wool mats on a synthetic binder	225	2	5	0.072	0.082	0.49
Same	175	2	5	0.066	0.076	0.49
Same	125	2	5	0.064	0.07	0.49
Same	75	2	5	0.058	0.064	0.53
Soft, semi-rigid and rigid mineral wool slabs on synthetic and bituminous binders	250	2	5	0.082	0.085	0.41
Same	225	2	5	0.079	0.084	0.41
Same	200	2	5	0.076	0.08	0.49
Same	150	2	5	0.068	0.073	0.49
Same	125	2	5	0.064	0.069	0.49
Same	100	2	5	0.06	0.065	0.56
Same	75	2	5	0.056	0.063	0.6
Mineral wool boards of increased rigidity on an organophosphate binder	200	1	2	0.07	0.076	0.45
Semi-rigid mineral wool boards on a starch binder	200	2	5	0.076	0.08	0.38
Same	125	2	5	0.06	0.064	0.38
Glass staple fiber slabs with synthetic binder	45	2	5	0.06	0.064	0.6
Mats and strips of glass fiber stitched	150	2	5	0.064	0.07	0.53
URSA Glass Staple Fiber Mats	25	2	5	0.043	0.05	0.61
Same	17	2	5	0.046	0.053	0.66
Same	15	2	5	0.048	0.053	0.68
Same	11	2	5	0.05	0.055	0.7
URSA Glass Staple Fiber Boards	85	2	5	0.046	0.05	0.5
Same	75	2	5	0.042	0.047	0.5
Same	60	2	5	0.04	0.045	0.51
Same	45	2	5	0.041	0.045	0.51
Same	35	2	5	0.041	0.046	0.52
Same	30	2	5	0.042	0.046	0.52
Same	20	2	5	0.043	0.048	0.53
Same	17 .	2	5	0.047	0.053	0.54
Same	15	2	5	0.049	0.055	0.55
B. Slabs made from natural organic and inorganic materials
Wood fiber boards and chipboards	1000	10	12	0.23	0.29	0.12
Same	800	10	12	0.19	0.23	0.12
Same	600	10	12	0.13	0.16	0.13
Same	400	10	12	0.11	0.13	0.19
Same	200	10	12	0.07	0.08	0.24
Fiberboard slabs and wood concrete on Portland cement	500	10	15	0.15	0.19	0.11
Same	450	10	15	0.135	0.17	0.11
Same	400	10	15	0.13	0.16	0.26
Reed slabs	300	10	15	0.09	0.14	0.45
Same	200	10	15	0.07	0.09	0.49
Heat-insulating peat slabs	300	15	20	0.07	0.08	0.19
Same	200	15	20	0.06	0.064	0.49
Plaster boards	1350	4	6	0.5	0.56	0.098
Same	1100	4	6	0.35	0.41	0.11
Gypsum sheathing sheets (gypsum board)	1050	4	6	0.34	0.36	0.075
Same	800	4	6	0.19	0.21	0.075
G. backfill
Expanded clay gravel	600	2	3	0.17	0.19	0.23
Same	500	2	3	0.15	0.165	0.23
Same	450	2	3	0.14	0.155	0.235
Same	400	2	3	0.13	0.145	0.24
Same	350	2	3	0.125	0.14	0.245
Same	300	2	3	0.12	0.13	0.25
Same	250	2	3	0.11	0.12	0.26
E. Wood, products from it and other natural organic materials
Pine and spruce across the grain	500	15	20	0.14	0.18	0.06
Pine and spruce along the grain	500	15	20	0.29	0.35	0.32
Oak across the grain	700	10	15	0.18	0.23	0.05
Oak along the grain	700	10	15	0.35	0.41	0.3
Plywood	600	10	13	0.15	0.18	0.02
Facing cardboard	1000	5	10	0.21	0.23	0.06
Multilayer construction cardboard	650	6	12	0.15	0.18	0.083
E. Roofing, waterproofing, facing materials
- Asbestos-cement
Asbestos-cement flat sheets	1800	2	3	0.47	0.52	0.03
Same	1600	2	3	0.35	0.41	0.03
- Bituminous
Bitumen oil construction and roofing	1400	0	0	0.27	0.27	0.008
Same	1200	0	0	0.22	0.22	0.008
Same	1000	0	0	0.17	0.17	0.008
asphalt concrete	2100	0	0	1.05	1.05	0.008
Products from expanded perlite on a bituminous binder	400	1	2	0.12	0.13	0.04
Same	300	1	2	0.09	0.099	0.04

One more nuance. The table shows two operating modes, A and B. Which one should I choose?

To do this, we look at another map-scheme, which divides the country's territory into zones of humidity:

Now let's turn to the table, which will tell you which of the modes to choose:

Before starting the calculations, one more important remark should be made. Only those layers are taken into account that provide a snug fit to each other, without ventilated air gaps. So, if the roof or wall is made with a ventilation gap, then all layers lying above it are no longer taken into account. For the same reason, corrugated roofing material cannot be taken into account.

For example, roof slopes have the following design: a solid plywood crate, on top of which a soft bituminous coating is laid. Under it is a layer of insulation (which will be calculated), and from below there is a lining with a natural clapboard. This means that, in addition to thermal insulation, three more layers will be taken into account in the calculation - bituminous coating, plywood and natural wood.

In order not to bore our readers with long calculations, we suggest using a special calculator that allows you to calculate the thickness of the insulation for walls, slopes and attic floors, in the design of which, in addition to thermal insulation, there are up to three more layers.

Calculator for determining the thickness of the insulation of walls, roofs and floors of the attic

Enter the requested values, and then click the "CALCULATE" button

Determine from the schematic map and enter the value of thermal resistance, R

Just 1.6

Convert m to mm

Enter the parameters of the first layer

Material thickness, mm

Enter the parameters of the second layer

Material thickness, mm

Thermal conductivity coefficient of the material, W/m°C

Enter the parameters of the third layer

Material thickness, mm

Thermal conductivity coefficient of the material, W/m°C

Decide on the type of insulation, find in the table the coefficient of its thermal conductivity

Enter the value of the thermal conductivity coefficient and click the "CALCULATE" button

How to carry out self-insulation of the attic

Having chosen the most appropriate work technology and the appropriate material for thermal insulation, having finished covering the roof truss system with roofing material and be sure to “sew” on both sides, you can proceed directly to the insulation of the attic.

In order to make it convenient to carry out work on the installation of insulation on the ceiling (roof slopes) and on the walls, first you need to arrange the floor.

Attic floor insulation

The process of warming begins with the fact that they are fixed to the floor beams, best of all - from the side of the lower floor, vapor barrier material. His canvases are overlapped by 200 — 250 mm with taped seams.
On top of it, on the same floor beams, boards are also screwed or nailed from the side of the lower room - this layer will become the “rough floor” for the attic and at the same time - lower parts of the attic floor.
If you want to create not only insulation, but also ideal sound insulation, you need to fill the aisle of beams, now from the side of the attic, with expanded clay of fine fraction.

Expanded clay is closed from above with another vapor barrier sheet, which is fixed to the beams with the help of rails.

Further installation will depend on the selected insulation:

- If mineral wool, sprayed polyurethane foam or polystyrene is used, then bars are fixed perpendicular to the floor beams at a distance corresponding to the width of the mats or thermal insulator panels, so that it fits between the guides as tightly as possible, without gaps.

- If you want to make the ceiling thicker, or if ecowool is used as a heater, then metal profile trusses are sometimes attached to the beams.

Then, between the bars or trusses, a heater is mounted, which, after installation, is also covered with a vapor barrier film.

Further, from above, the entire “pie” is sewn up with boards or thick plywood. Fastening is carried out to bars or profiles, between which insulation is laid or sprayed.

The next step is laying a plank or plywood floor

When the floor is insulated and laid, it is a reliable foundation, you can proceed to the insulation of the ceiling.

Insulation of the ceiling and walls of the attic

1. If a decision is made to independently insulate the walls and ceiling of the attic using polyurethane foam spraying technology, then you need take action to ensure safety, since in the liquid state this material is very toxic - it emits vapors hazardous to human health. To protect yourself from their effects, you must wear a special suit and mask that cover the respiratory organs, eyes, skin of the face and hands.

Spraying starts from the bottom line, i.e. from the floor or from a certain section of the wall, lead in horizontal stripes, gradually climbing up and moving to the ceiling. Polyurethane spraying is carried out in layers or immediately in one thick layer. Having insulated one side of the attic, the same action is performed on the other side.

It is not recommended to take on such a technological process on your own without having the appropriate experience, even if it is possible to rent the necessary equipment. It will be very difficult to eliminate the mistakes made, since the removal of cured polyurethane foam is an extremely difficult task.

2. Rolls or mats of thermal insulator also begin to be laid from the bottom of the room, tightly laying them between rafters or battens.

If, for one reason or another, the insulation is poorly fixed between the ceiling beams (rafters, rails), then additional bars or metal profiles can be attached to them, which will become a support for mats or panels.

Work with mineral wool should also be carried out, taking measures to protect the respiratory tract, eyes and skin.

Having insulated the side walls, in the same way they carry out work on the thermal insulation of the gable walls of the attic.

A crate made of timber is mounted on the gable wall, into which insulation is laid or sprayed.

If expanded polystyrene panels were used as panels, then gaps will inevitably remain, which will become "cold bridges". They must be filled with mounting foam or, at least, carefully caulked with mineral wool.

The next step is sheathing the insulated surface with a vapor barrier film. It is fastened with staples, and a crate is stuffed on top, along which the walls and ceiling will be sheathed.

Video: how to solve the problem of reliable vapor barrier

Sheathing of insulated walls

Sheathing the walls and ceiling of the attic will complete the entire process of insulation and make the room neat, giving it a truly residential look.

This stage can be carried out using either wooden lining. It is better not to use laminated material (Fibreboard) or polymer panels, as they will not be able to create additional thermal insulation.

Drywall is convenient and easy to install - it immediately closes large areas and makes the walls perfectly even.

After installing the GKL sheets, the seams between them and the recesses from the heads of the self-tapping screws must be leveled with gypsum-based putty, and then thoroughly cleaned.

On drywall, after applying a penetrating primer, wallpaper or fabric is well glued, and water-based paint is also applied. The advantage is that this material makes the walls warm to the touch, creating a feeling of comfort.

Very often, wooden lining is used to finish the attic, which looks win-win for arranging almost any room. The natural warmth of color and the beauty of wood structure will make the interior comfortable and cozy.

A great option for a residential attic - sheathing with natural clapboard

Recently, for additional insulation of the attic, infrared film is increasingly being used, both for walls and for the floor. It connects to the power supply and turns on as needed, providing very fast heating of the surfaces in the room. It should be noted right away that it is better to entrust its installation and connection to specialists who are professionally engaged in this work.

From above, the film can be closed with drywall or clapboard, but you need to accurately calculate the places for their attachment. It is best to mount thin slats between the film strips at a certain distance, on which the finishing material will be fixed.

The attic in the house is a space with great potential. It has a spacious area to serve as a place to store things or a seasonal vacation, and a non-trivial shape that can become the basis for the implementation of design ideas. Not to use its opportunities is a big omission.

You can organize the space of the attic floor in different ways. But the most rational of them is the arrangement for living quarters. This will help self-insulation of the attic from the inside. The choice of material and the order of work will also not be difficult after a detailed consideration of the features of the materials and the insulation process.

Why insulate?

A good, warm attic has a number of advantages over an uninsulated floor:

Can be used as a living space all year round.
An uninteresting shape is suitable for interior decoration in an unusual style.
The upper floor, due to its isolation and unusualness, can serve as a bedroom, study or children's room. Especially in the attic like, of course, children.
Skylights are arranged differently than usual and let in a lot of light. This is useful if a children's room is located there, and is also suitable for other purposes, because natural lighting is always better than artificial.
When transferring the function of any room in the house to the attic floor, a lot of usable space is freed up.

At the same time, attic insulation, despite the name, works in the opposite direction. Summer stuffiness and heat, concentrated under the roof of the house, are not the best companions of comfort. So that the air in the space of the attic floor does not heat up because the sun heats the roof all day, thermal insulation is needed.

Many people forget about this, choosing to insulate the attic from the inside, and instead of a room for all-season use, they get an option for wintering. In summer it is impossible to be there because of high temperatures and stuffy air.

Why insulate the attic is clear: increase the useful area of \u200b\u200bthe house by turning the attic into a living space. What specific type this room will be depends on the individual needs of the family. It can accommodate a greenhouse, a dining room (which is very convenient, since it will be easier to arrange an exhaust hood, and the smells of food will definitely not penetrate into other rooms), a children's room, a bedroom, an office, a pet room, a dressing room, a guest room.

Roof construction options

The convenience of an attic for living largely depends on its size and the shape of the roof, which forms the walls and ceiling of the room. The form also affects the complexity of the warming procedure. The type of roof is laid during construction in accordance with the design of the building.

In total, there are about a dozen types of roofs, to one degree or another suitable for arranging an attic:

Shed. The slope can be on the left or on the right side. This determines the scheme of the future home, designed in accordance with building codes. This type of roof is not the best, but not the most inconvenient option for a living space. At least one half of the attic is suitable for a person to fit in it at full height and be able to move freely. The second can be assigned to the organization of storage systems or a bed.

Gable or gable. Available in both symmetrical and asymmetric versions. In this type of attic, all free space is concentrated in the place where the roof has the highest point. There is less and less of it under the slopes, and if the slope is gentle, then most of the area will not be used.
Hip. A roof with four slopes: two in the form of a trapezoid, two in the form of beveled triangles.

Shatrovaya. A kind of hip roof, which is erected over the base of a square-shaped house. All 4 slopes in this case have the same type of beveled triangles.
Half hip. This is a type of gable roof, in which, for practical purposes, the side slopes on the gable part are cut off. It is more convenient for arranging the attic floor than the previous two options.
Slightly less common semi-hip four-pitched roof. Its pediment parts are formed by windows, and slopes are located under them.

Mansard roof. It is recognized as optimal, since it is closest to the coveted U-shaped shape of the dwelling. Such a roof does not impose any restrictions on the arrangement of functional areas inside the attic floor. You can easily place a child's room in it, which can later be converted into his own office or bedroom.
Broken or multi-tweezer. These are options for complex design ideas. It is impossible to say unequivocally how suitable they are for arranging a warm attic, since their shape can be very diverse. But those species that are most similar to the U-shape are definitely suitable for this purpose.

Load calculation according to SNiP

When it comes to attic insulation, it is necessary to consider several types of SNiP: general rules for arranging residential premises and rules for choosing materials for thermal insulation of a residential building.

Calculation of the load on the supporting structures of the building. The own weight and thickness of materials, decorative finishes, interior design of the attic significantly increase the load on the supporting structures in any type of house. The maximum allowable load for each option is different, but the planned changes should not exceed it.

Proper assessment of the structures under construction. For the reconstruction of the house, which in many cases will include the conversion of the attic into a residential attic, legal grounds are needed. Each case is individual.

In one, if the documents are drawn up correctly and the construction of the house occurs immediately with the attic, it can be redone in any way without unnecessary red tape.

In a private house, the construction of an attic depends only on the height of the floors and compliance with the load standards for load-bearing structures; in an apartment building, it is important to take into account its status. If this is an architectural monument, the construction of an attic cannot be legalized.

Compliance with sanitary and hygienic standards. They regulate the minimum height of the attic room, the degree of its illumination and insolation - protection from ultraviolet rays.
The number of floors in the house. Building codes allow a maximum of three floors, while basements and semi-basements that protrude more than a meter above the ground are also considered. If, after insulating the attic, it becomes a full-fledged living space and the fourth floor in the house, then such a building will be considered illegal. In theory, it should be demolished.

Degree of fire resistance. It is measured in minutes and in most positions is:

for lower floors 60 minutes,
for the attic - 30, since the fire spreads upwards and the risk of ignition of the lower floors from the attic is less.

When arranging an attic, especially a wooden one, for a living space, all the requirements must be met: treat the wood with special impregnations that prevent the spread of flame, choose fire-resistant materials, and lay communications with high quality.

It is also important to calculate which layer is needed when using different materials. As a rule, the recommended thickness and density of foam, mineral wool, polyurethane foam or foam glass is indicated by the manufacturer or GOST for a particular material.

Review of materials: pros and cons

The construction market offers the materials themselves in abundance. In this case, only a heater is not enough, since technology involves the layer-by-layer use of materials for various purposes:

Material for roofing and walls. These are the elements that form the basis of the attic space. The walls of the house can be wooden, brick, block. For roofing choose professional sheets, ondulin, slate, metal or ceramic tiles.
Bars for the counter-lattice. The timber is used wooden, mounted on the rafters. The counter grille is necessary to create air circulation so that condensation does not form under the roof sheeting.

Windproofing and waterproofing. Polypropylene and polyethylene films, various non-woven roll materials are used. Films with anti-condensation coating are in priority. They are overlapped by 20-25 cm between the beams and the roofing material, glued together.
Thermal insulation. Various types of insulation, which are laid at a distance of 25 cm from the waterproofing film under slate or tiles, and 45-50 cm under sheet materials.
Vapor barrier. It is necessary from the outside of the insulation to protect it from vapors and moisture contained in the indoor air. Various film and foil materials are used to prevent the formation of condensate and the greenhouse effect.

Internal crate. Decorative decoration of the ceiling and walls. In some cases, when the height of the roof allows, you can "hem" the ceiling. The air space between it and the roof will make the thermal insulation more effective.

If there are no questions with most points, then the choice of insulation is the most crucial moment. His choice is wide, which is both a plus and a minus, since it is necessary to evaluate a large number of options.

Insulate the attic:

sawdust;
mineral wool;
ecowool;
basalt type of cotton wool;
polyurethane foam plates (PPU);
extruded foam;
penoplex;
foam glass;
construction foam;
foil and heat-reflecting material.

The use of sawdust for thermal insulation is a proven and effective method. It is cheap, the mixtures are prepared by hand, but with the availability of alternative materials, the method is already outdated. A lot of time is spent, working with sawdust is clean, but unpleasant, and the flooring will not differ in durability. Ecological cleanliness in this case is rather not at hand, because wood fibers are an excellent breeding ground for organisms.

Ordinary polystyrene also belongs to the materials of the past. It has a number of advantages: low weight, low price, ease of installation alone, a fairly long service life, good insulating properties. But the disadvantages are still significant: fragility and fragility, retains moisture inside, a suitable environment for the reproduction of living organisms, a thick layer of material is needed.

Mineral wool is a more relevant insulation. Its advantages:

high coefficient of thermal insulation;
resistant to moisture, chemicals and alkalis;
provides good ventilation in the room;
promotes sound insulation;
high coefficient of fire resistance;
long service life;
strength;
safety for residential use.

Flaws:

With poor organization of the waterproofing and vapor barrier layers, ingress of precipitation on the material, mineral wool loses several percent of thermal conductivity.
Capable of accumulating dust over time.
High-quality mineral wool is quite expensive, but it is environmentally friendly. There are often fakes on the market in which the formaldehyde content exceeds the norm. They are harmful to health and are prohibited for use in residential areas.

Ecowool, in its essence, represents cellulose fibers for three-fourths of the composition, and the remaining share is made up of substances that allow the use of cellulose as a building material - these are borax and boric acid. They increase the fire resistance of cotton wool, prevent the appearance of microorganisms, fungi, rot.

The advantages include the good ability of the insulation to retain heat in the room, not to interfere with ventilation, high-quality insulating properties, natural and safe raw materials based on ecowool.

The material also has a minus, and a significant one. Ecowool is not produced in the form of plates or sheets, it is a loose fiber that must be applied wet using special equipment. And to work with the equipment you will need qualified installers.

In addition to ecowool, foreign manufacturers also offer other types of insulation based on plant fibers: ecolen and cotton fabric insulation.

Another type of cotton wool is basalt. It is related to the mineral. Since its components are present in the composition, but the basis of the material is basalt rock. Basalt imparts unique qualities to the material.

Its advantages:

components of organic origin without formaldehydes and harmful resins;
thermal insulation qualities, sound insulation;
does not ignite, does not support combustion;
biostable;
plates are convenient and easy to use;
served for decades.

Flaws:

high cost of insulation per square meter with basalt slabs;
absorbs moisture well.

The third type of wool, glass wool, has similar characteristics. It is more convenient to use, because the material is rolled.

Extruded foam plastic or extruded polystyrene foam combines the qualities and advantages of mineral boards and conventional foam plastic, thanks to a special production technology.

Its performance characteristics are mostly positive:

lightweight, but durable - this allows you to use it for insulation in large quantities, work with it simply alone;
closed pores of the material are moisture resistant;
easy to cut into fragments, it is not brittle and does not crumble;
does not cause interest, as a habitat, neither in fungi, nor in rodents;
low cost.

The disadvantages include: vapor permeability, low fire resistance.

The group of gas-filled plastics of the new generation also includes polyurethane foam (PPU). Its advantages make the material one of the best for insulating the attic floor: it is lightweight, moisture and fire resistant, does not accumulate dust, does not attract living organisms, and is very durable.

There are two types: sheet and sprayed. Sheet material is very convenient in that it does not crumble in the process of cutting fragments and closely fits the part to the part. The sprayed type of protection creates a monolithic layer under the roof, due to which it is not afraid of precipitation and cold. And also it has good adhesion to various surfaces, is resistant to the appearance of microorganisms and allows installation work to be carried out as soon as possible.

The sprayed material creates better thermal insulation and helps muffle extraneous sounds, but it has two serious drawbacks. Firstly, the application will require an expensive service of professionals with special equipment. Secondly, it is so dense that it "does not breathe". Humid and stuffy air will accumulate in the room if it was not possible to organize additional ventilation.

It is advisable to use both types of PPU at the same time. Large areas are covered with sheet material, and hard-to-reach places and cracks are treated with spraying. This will completely solve the problem of even the coldest attic.

Foam glass is a rare and unfairly relegated material. The reason for this is simple - a very high price. Foam glass, as the name implies, is obtained by foaming fiberglass. It turns out a porous (cellular) material that is absolutely not susceptible to fire, safe, durable and meets all the requirements for insulation. If financial possibilities allow, then foam glass as thermal insulation should be considered first of all.

A separate group from plastic and glass derivatives are foil materials for insulating rooms from the inside. By themselves, they have a small thickness, so they are often combined with various variations of foamed cellular materials that are inside between two layers of foil.

The advantages of reflective materials are obvious:

Light weight and small thickness. The attic is rarely large, especially considering that its dimensions are hidden by the shape of the roof, and 20 mm foil sheet is much more practical than 200 mm foam.
The material is easy to cut, does not crumble, does not slip on the surface.
There are variants of self-adhesive sheets, in which one side is covered with a reflective layer, and the other with an adhesive adhesive. They greatly simplify installation work.
Foil is an excellent heat reflector. Thanks to its abilities, in the cold season, heat does not leave the room, and in hot weather it remains outside.
Reflective coatings are hydrophobic, they simply repel water.
It is at the same time isolation from precipitation, dust, wind, cold.
Despite the minimum thickness, it copes with the function of sound insulation.
Elastic and flexible.
Biostable.
Do not emit toxins and formaldehyde when heated.
Durable.

How to choose?

The choice of a suitable insulation is a crucial stage in the arrangement of a living space on the attic floor.

There are several important factors to consider:

Accounting for climatic conditions. If severe frosts rage in the region during the cold season, the insulation should be chosen cellular or porous. Its structure allows warm air to fill empty spaces and keep the heat in the room. It works like PVC profiles and double glazing on windows. The more layers of cells, the better the material, so the layer thickness should be more than 1-2 cm.
For regions with high humidity, the hydrophobicity of the material comes first. All types of cotton wool are undesirable here, but derivatives of polyethylene and plastic will be just right. You can safely use polystyrene foam and polyurethane foam.
With a large amount of precipitation in winter, giving a load on the roof, lightweight materials are preferred. For example, foam and foil.

Accounting for indicators of moisture and fire resistance. Even if the climate does not abound in rain, protecting the insulation from moisture is very important. Wet material ceases to perform its functions, as its thermal conductivity changes, and gains weight.
As for fire safety, it is rather compliance with all norms of SNiP. Choosing fire-resistant material is not difficult. Most manufacturers add substances called flame retardants to organic raw materials for the manufacture of insulation. They prevent the spread of fire.

The ability of a material to hold its shape. Measured as modulus of elasticity and resistance to deformation. It depends on this whether it will create a monolithic reliable protection or will begin to sag and drafts and ventilated places will appear in the room. The undisputed leaders in this respect are not sheet, but sprayed materials.
Material coefficients for several characteristics: thermal conductivity, vapor permeability, sound insulation index.
The composition of the substance. For the arrangement of a living room in the attic, it is recommended to use environmentally friendly materials, without resins, formaldehydes and toxic substances. Various impregnations are acceptable if their presence meets the requirements of GOST.

The type of materials used in the roofing also matters.

Under the metal tile

Insulation of the attic ceiling under such material should be properly carried out with the help of a layer that is not afraid of moisture. Features of the structure and installation of metal tiles are such that water can get under it. The use of foam materials based on plastic or glass is optimal here, but if the choice fell on mineral wool, it is important to take care of a good waterproofing layer.

It is also necessary to choose a material with an anti-condensation coating. After the condensation reaches a certain temperature, it will also turn into water that is dangerous for the insulating layer. The problem can be solved with the help of polypropylene films, geotextile coatings and super diffuse membranes.

The disadvantages of metal tiles include the fact that its unusual shape allows precipitation to accumulate between the layers of the coating, which is almost impossible to make completely airtight. High-quality ventilation under the roof will help to level the damage from this as much as possible. Natural in this case may not be enough, it is necessary to equip a forced one.

Such problems also apply to ceramic relief coating and slate sheets. All of them have the same shape, which does not allow you to fit the sheets closely.

Under corrugated board

It is less problematic in terms of leaks and condensation, as the sheets fit more tightly, and the joints are treated with sealant and paint. But the material has its own characteristics. Firstly, it is very cold and the insulation must be of high quality and impressive in thickness. Secondly, when it rains under a corrugated roof it is very noisy, you need a material with high sound absorption rates.

From the list of suitable materials, it is necessary to exclude thin foil sheets, fiberglass, cellulose insulation like eco-friendly. Their thickness and sound insulation performance are insufficient to ensure a comfortable stay in the attic under the corrugated roof.

For the attic above the bath

Along with the type of materials for the roof, the location of the attic must be taken into account: either it is located above all living quarters, or above a part of the house.

One of the problematic options is the attic above the bath. With such an arrangement, it is difficult to equip a living space in it. It is more suitable for a relaxation room, a small living room or a play corner, which is necessary after bath procedures.

The main difficulty in choosing materials lies in the microclimate of the room above the bath, which is different from the microclimate above the living rooms. The temperature and humidity conditions in it are unstable, and the possibility of condensation is very high. Of course, under such conditions, neither sawdust, nor cotton wool, nor ecological cellulose-based heaters are suitable. It requires hydrophobic materials such as expanded polystyrene and polyurethane foam, foil coatings, good vapor barrier and forced ventilation.

Winter residence houses

There is no universal solution for winter attic insulation. It all depends on the climatic conditions and materials used in the construction of the house.

Long and harsh winters - a solid, porous, temperature-resistant insulation. Warm climate - any material suitable for the type of roof.

In a private wooden house, due to the properties of wood, a fairly thin insulation retains heat. Cellulose-based materials, on glass or plastic are also suitable. You can use foil with a minimum thickness.

In brick houses with corrugated, tile or slate roofs, additional insulation in the form of air spaces is necessary. These can be dense porous materials and several layers between them. Insulation of a frame house does not require much effort, since its design already provides for all the features of specific climatic conditions. Any moisture-resistant and fire-resistant materials are suitable here.

How to insulate with your own hands?

The technology for creating thermal insulation in the attic is also available to non-professionals. The key to success is not in the experience of installation work, but in the correct selection of material, the consistent implementation of actions to create a continuous insulated contour and accuracy.

The procedure is as follows:

Calculation of the allowable load and the optimal thickness of the material.
Selection of materials and necessary tools (including safety equipment).
Preparation of the premises: cleaning, dedusting, processing of wooden structures with protective impregnations.
Lathing installation. This is an important and mandatory step that amateurs skip out of ignorance. The device for thermal insulation of the attic without crates and counter-battens is considered a gross mistake. It is nailed from the inside over the entire area of \u200b\u200bthe roof.
Laying a waterproofing film or diffuse membrane. The fastening should not be stretched, it is better to let the material sag a little. The sheets overlap each other (15-25 cm) and fasten with tape or foil. A gap of 20 to 50 cm is required between the membrane and the crate.
Heater installation. The methods are different, depending on the type of material and the location of the rafters. Roll material can be fastened with a slight overlap and fixed with tape or a stapler. Sheet insulation for finishing the roof and walls is laid close, taking into account a slight shrinkage in the future. The junction is made as close as possible, the seams are processed with adhesive tape. You can use screws and nails for very dense materials.

It is important to join well in the corners of the gable and in such difficult areas as the ridge, valley, overhangs. For this, small parts of the material are used, separated by hand.

Particular attention is paid to the contour of the windows. The room will remain cold if warm air escapes through the cracks near the window.

The sequence is as follows: insulation of the roof, ceilings, gable, partitions, walls. The floor can be insulated both before and after.

Floor insulation is more variable, since it is less affected by precipitation, winds and frosts.

It can be dry backfill, and sawdust, and mineral wool:

Installation of vapor barrier. It is overlapped, like a membrane, fixed in various ways. As a rule, there is a line on the material that marks the width of the joint between two sheets.
Lathing if necessary.
Decorative finish.

Common mistakes

The correct thermal cake for roof insulation is mounted in compliance with many nuances.

Non-professionals often make the same mistakes that affect the quality of attic thermal insulation:

lack of ventilation gap from the ceiling to the membrane. As a result, the insulation freezes and ceases to operate;
strong sagging of the membrane - this reduces the gap required for ventilation and leads to the formation of condensate;
attempts to save on insulating materials, laying them without the necessary joints, as a result of which gaps are formed and heat escapes outside, warming the roof, and not the room;

tamping the material to such an extent that it warps and crumples, losing its properties;
unlined cornices - this leads to the fact that precipitation gets free access to the insulation and saturates it with moisture;
lack of ventilation;
lack of adhesive tape or tape at the joints of the sheet material.

Use hard and dense materials or spraying. They are better fixed and do not deform in the process.
Increasing the distance between the attic ceiling and the top of the ridge will create an "air cushion" and improve the quality of the warm contour.
It is better to leave a gap for ventilation not only between the crate and the membrane, but also between the membrane and the insulation.

For the first time, attics appeared in France, it was there that the famous architect F. Mansara began to use the attic spaces empty before him. He organically fit an ordinary attic into the general style of the house, placing living rooms or utility rooms there.

The attic allows you to expand the area of \u200b\u200bthe living space and gives the house expressiveness and comfort.

Attics are not only useful in terms of expanding living space, but also significantly affect the overall appearance of the house, giving it more expressiveness and comfort. In an average house, their area is about 90 m 2, that is, this is far from a small space; several rooms can be perfectly arranged there. The attic in a wooden house looks especially organic. But, despite the remarkable properties of this room, it is worth remembering that it is it that is in contact with the environment the most, which means that it needs thermal insulation most of all. On the insulation of the attic in a wooden house and will be discussed further.

General requirements for insulation

When erecting an attic, it is worth remembering that it is through the roof of the house that the main heat losses occur, so the attic must be insulated very carefully, using suitable materials and using the best technology. Experienced craftsmen know how to insulate an attic in a wooden house, the well-being of the whole house depends on their skill and experience.

Poor insulation of the attic in a wooden house is not only cold, dampness and a disgusting microclimate, but also the decay of the tree, its deformation and destruction.

But full-fledged thermal insulation is unthinkable without combining it with equally high-quality hydro and vapor barrier, only the union of these three qualities can give warmth and comfort not only to the attic itself, but to the whole house.

The space under the roof not only has a large area of contact with the external environment, which means it bears the maximum heat loss, but is also most prone to such a problem as condensate. This means that, in addition to insulating the attic, the owner of the house needs to take care of good ventilation. Thus, the whole complex of attic insulation measures is a multi-step and difficult process, especially considering the structural complexity of this space.

If possible, it is desirable to produce insulation not only from the inside, but also from the outside.

Back to index

Insulation of the roof of a wooden house

largely depends on how well you carried out the thermal insulation of the attic. If everything is done well, then in the uppermost part of the house you will always have cool in summer and warm in winter. Among other things, high-quality roof insulation is also the absorption of outside noise and comfortable silence inside the house.

The roof is not only a roof covering resting on a wooden frame, it is also an insulating cake that is located between them. It includes:

properly selected layers of a vapor barrier layer that protects the entire structure from moisture;
a heater that helps dry air not to let heat out in winter and inside in summer;
a waterproofing layer that protects the remaining layers and the whole house as a whole from the penetration of moisture from the atmosphere;
the air gap between the layers also plays an important role in both ventilation and thermal insulation of the room.

These requirements show that attic space insulation must be calculated at the design stage of the entire house, and not at the moment when you decide to use the space under the roof for your needs. A well-insulated roof will not allow the penetration of cold air from the street, because when it comes into contact with the warm air of the house, condensate drops are formed that accumulate in various places (rafters, ceiling, space between the layers of the cake). And this is the beginning of the end. Accumulating moisture is a terrible enemy for any house, but especially for a wooden one. This will entail an increase in the cost of heating the house, since heat losses will increase sharply due to high humidity, as well as much more dangerous consequences - rotting and destruction of wooden structures.

It is clear that only an experienced builder can carry out such work with high quality, but a beginner can also do this if he does not save on materials and follows all the requirements and advice of manuals and instructions.

But what material to choose for insulation?

Back to index

The choice of insulation and its characteristics

So, let's start choosing a heater for the thermal insulation of your attic.

The best insulation in terms of its characteristics is mineral wool.

Many homeowners insulate the attic floor with foam sheets. The advantages of such material include low price and weight, the latter is important for those houses where it is necessary to avoid unnecessary load on the structure of the building. But it's still not the best choice. After all, polystyrene has one very significant drawback - it is a combustible material, and it is highly recommended to use fireproof building materials for insulation. In addition, foam plastic is not suitable as a heater due to low vapor conductivity, which means that it will not be able to pass accumulated water vapor, increasing the humidity of the room. Styrofoam is also characterized by low strength and the fact that it provides comfortable housing for rodents.
Extruded polystyrene has more attractive characteristics than polystyrene. It resists moisture well, has low thermal conductivity, thanks to pre-made grooves in the sheets of material, its installation is very simple and convenient. But, like polystyrene, polystyrene foam has low vapor permeability. In addition, its price is unreasonably high.
The next most popular is glass wool. The advantages of such a material can be listed for a long time - these are excellent thermal conductivity, ease of installation, the absence of organic compounds in the composition, which means a long service life, good vapor permeability, absolute fire safety of the material and much more. But there are also disadvantages, glass wool is dangerous when working with it, since small particles of glass from crumbled cotton wool, penetrating into the mucous membrane of the eyes, respiratory tract or skin, cause itching, an allergic reaction and irritation. Therefore, installation can only be carried out in special clothing, glasses and in a gauze bandage. Moreover, it is not easy to get rid of glass dust, so it is better to simply throw out all the clothes, washing will not help.
The best option is mineral wool, or more precisely, basalt wool. It is less dangerous than fiberglass, but at the same time it has no less advantages as a heater. Mineral wool has excellent noise-absorbing properties, in addition, it will last you much longer than fiberglass. Experienced craftsmen prefer to work with this material.

Back to index

Attic gable insulation

The insulation of the roof has already been considered above, this procedure is done during construction, but in addition to the roof, the attic also needs insulation of the gable and floor.

The internal insulation of the attic gable begins with the installation of beams on the walls of the gable. The distance between them should correspond to the width of the insulation used.
The first layer is a waterproofing layer with good vapor permeability.
The next layer is the insulation itself.
Then again a layer of vapor insulation, and you can sheathe it with finishing materials.

In general, this simple scheme includes the whole process of warming the gable, but, like in every complex process, it has a lot of its own nuances that will affect the overall efficiency.

Try to install without damage to the material, with minimal seams and in strict accordance with the instructions.

Warning: Use of undefined constant WPLANG - assumed "WPLANG" (this will throw an Error in a future version of PHP) in /var/www/krysha-expert.php on line 2580

Warning: count(): Parameter must be an array or an object that implements Countable in /var/www/krysha-expert.php on line 1802

The desire to live better, to have spacious houses, separate rooms for each family member and guests is a completely natural desire of our fellow citizens. Improvement of living conditions can be achieved in two ways: build large and expensive houses using traditional technology or use modern solutions and convert attic spaces into residential ones. These are the so-called attic rooms, this method allows you to achieve your goals with minimal financial losses.

Due to the successful combination of housing quality, living comfort and the estimated cost of construction work, attic rooms are very popular among domestic developers. Currently, there are many technologies and special materials for the insulation of such premises. In order to make the right and informed choice, it is recommended to briefly familiarize yourself with their physical and operational characteristics.

The industry produces a wide range of materials used for building insulation. Regardless of the production technology, all of them must meet several universal requirements.

These are general requirements, and popular heaters meet optimal performance to varying degrees.

What materials can be used to insulate a mansard roof

We will give a brief description of all possible options, and based on objective characteristics, it will be easier for developers to make the right choice.

Table. Types of insulation for the attic

Name of insulation	Physical and performance characteristics
	The most advertised material for roof insulation. It has good heat saving performance, it is technologically advanced, it is easy to cut and fit. Mineral wool does not emit any harmful chemical compounds into the air, does not burn, is allowed for use without restrictions. These are positive qualities of the material, but there are also negative ones. Mineral wool is very hygroscopic, it can absorb a large amount of moisture. As a result, thermal conductivity increases sharply, next to wet cotton wool, all wooden structures of the truss system quickly rot. To protect against moisture penetration, it is necessary to use special membranes, and this is an additional increase in the estimated cost of construction. In addition, the price of mineral wool is the highest among all existing heaters.
	A highly sought after material. In many important performance indicators, it surpasses the characteristics of mineral wool: it has low thermal conductivity (better than that of mineral wool), it is perfectly cut, it is easy to install in the niches of rafter legs, and it has a minimum weight. It does not absorb moisture, for it there is no need to install moisture and vapor protection, which has a positive effect on the cost of attic space. In addition, it is one of the cheapest roofing materials. As for combustibility, modern types have special additives, now the material does not support open combustion. This means that a short circuit cannot set fire to the foam. The amount of evaporation of chemical compounds does not exceed the established norms, and the insulation itself is additionally covered with finishing materials, which further reduces the likelihood of negative consequences. Another advantage is that foam plastic can be used to insulate roofs not only from the inside, but also from the outside, laying it under the roofing.
	Like polystyrene, it is recommended to use it if necessary to insulate the roof from the outside. In terms of physical parameters, it does not differ in any way from polystyrene, except for increased values of mechanical strength. But for roof insulation, strength is not critical. Disadvantages - high cost.
	During the insulation of structures, it is blown with the help of special equipment. During solidification, polyurethane foam expands and hardens. The most unfortunate material from all points of view. To achieve a thickness of 10-15 cm, it is necessary to repeat the treatment three times, it is expensive, time-consuming and economically inefficient. Experienced builders are strongly discouraged.
	A fairly new and rare insulation, it is made from pulp production waste or waste paper. Only one thing can be attributed to the advantages - the absence of harmful compounds. All actual performance characteristics are much worse than the heaters described above in the table.

Prices for thermal insulation materials

Thermal insulation materials

Before deciding on the choice of insulation, it is recommended to carefully compare the objective characteristics of the materials, while not paying much attention to the marketing moves of manufacturers, but trusting independent information.

And one more very important point: if the thickness of the insulation does not correspond to the climatic zone, then you should not expect a great effect from such insulation. No need to save, it is better to make the thickness with a margin of about five centimeters.

The internal insulation of the attic has an undeniable advantage - the possibility of carrying out thermal insulation work regardless of the season. However, this approach has several important nuances, ignoring which can nullify all efforts and financial investments. It is easier to prevent undesirable consequences than to eliminate them, agree?

We will tell you how to act correctly in order to avoid mistakes. In the article, we described the features of using different heat-insulating materials, gave tips on choosing the best insulation, and also told how to avoid condensation in the roofing pie.

The detailed attic roof insulation technology will help you do all the work yourself, without resorting to the help of specialists.

There are a lot of heaters. However, not all of them are recommended for installation in a residential attic. The attic space is characterized by a fairly high humidity due to the rise of heated air from the lower floors of the cottage. Plus, one should not forget about environmental friendliness and material safety.

If the attic is non-residential, then due to natural ventilation through the vents, spotlights and dormer windows, the steam quickly disappears from it to the street. As a result, condensation does not form inside, and the rafter system is not exposed to the negative effects of excess moisture.

In the attic, the situation is different. When it is warmed, it is necessary to create a barrier for the heat to escape to the outside and reduce air exchange with the street. As a result, all the steam remains inside the attic rooms.

Therefore, if the insulation is not reliably protected from moisture, then it will not last long. After all, any heat-insulating material, after getting wet, partially or completely loses its properties.

When choosing a heater, it is necessary to evaluate it:

thermal conductivity;
vapor permeability;
volume weight;
combustibility;
soundproofing;
environmental safety.

If you choose too heavy material, then the rafters will be overloaded. And the attic is often equipped from a non-residential attic. Rafter beams, in this case, are not designed for unnecessary additional loads. It's not worth trying your luck here.

In terms of thermal conductivity, most heaters on the market are similar. It is only necessary to choose the right thickness to achieve the required thermal insulation parameters.

It is not recommended to use sprayed polyurethane or foil polyethylene for insulation of the attic from the inside due to the high risk in case of making the slightest mistake when installing condensation directly on wooden rafters

Of the entire range of thermal insulation materials, mineral wool (basalt) and are most suitable for internal attic insulation. Moreover, the first option is more preferable than the second. Mineral wool is not combustible and has better sound insulation.

It is not worth taking glass wool because of its predisposition to crumbling. Small glass particles are very dangerous for humans. And ordinary foam is also not recommended for use in the attic. Compared to XPS, it is more flammable and environmentally harmful. In addition, it will have to be laid in a thicker layer.

Dew point problem

Ideally, the roof in the attic should be insulated from the outside at the stage of forming the roofing pie. However, often this is done the other way around from the inside, when the house is already covered with a roof. And here certain problems arise.

The correct and ideal roofing cake is several layers of different materials laid on top of the rafters tightly on top of each other without gaps. Such a sandwich guarantees that it will be located on its outer side. As a result, all the condensate formed outside will quickly evaporate into the atmosphere.

When insulating a mansard roof from the inside, it is extremely important to leave a gap between the insulation and the existing roof for ventilation and evaporation of condensate formed due to temperature changes.

Making insulation from the inside, after the installation of the roof, it is impossible to form the exemplary roofing pie described above. It will not work to press the insulation against the roof so that there are no voids between them at all.

But steam always moves towards cold air. And then, each of the formed cavities will begin to accumulate condensate and moisture in itself. And this is a direct path to damage to the thermal insulation material and wooden elements of the truss system.

With internal insulation of the attic, the dew point has to be shifted into the space between the laid roof and the insulation, leaving an additional gap of 5–10 cm for ventilation there. Only such a technology and such a cake will make it possible to avoid moistening the heat-insulating material.

In order to achieve proper air exchange in the under-roof space, it is recommended to install deflectors on the ridge and provide special holes in the eaves

To reduce the amount of water vapor in the insulation, its installation should be carried out using a vapor barrier film. A vapor barrier is mounted from the inside of the attic on top of the thermal insulation material.

The steam must first encounter this film and for the most part remain in the room. The less it gets into the insulation layer, the better.

Mansard roof insulation technology

To insulate the attic from the inside correctly, you need to create a cake of five layers, starting from the roof inward:

Ventilated air.
Wind-moisture insulation from a vapor-permeable membrane.
Vapor barrier.
Attic ceiling lining.

Vapor barrier is made of glassine, polyethylene or polypropylene film. The best option is special membranes, in which one side is rough and the other is smooth. With these materials, the risk of condensation directly on them is reduced to almost zero.

For a vapor barrier material, the vapor permeability should not exceed several tens of grams / m2 per day, for vapor-permeable membranes this figure is hundreds of grams / m2 per day and more - these films cannot be confused

For the organization of wind-moisture insulation, membranes are suitable:

porous;
two-layer film;
three-layer superdiffusion;
perforated.

Superdiffusion membranes will last the longest and are most effective. However, they are more expensive than other options.

At the same time, it is recommended to use perforated fabrics and films when insulating a residential attic only as a last resort. They are more designed for waterproofing cold sloped roofs in non-residential attics.

When installed with a heater in a warm room, these materials are often covered with frost in severe frosts, which reduces their vapor permeability to nothing.

Layer #1 - Ventilation underlays

Before you start insulating the attic from the inside with your own hands, you first need to treat the wood of the rafters with antiseptics and fire retardants. Only then will it be possible to start forming a heat-insulating cake.

It is best to mount the insulation from the inside of the attic on a special crate under the rafters, but most often this material, together with the upper vapor-permeable film, has to be laid between the rafters

If the insulation is knocked out from below the rafters, then the interior space of the attic will be reduced. The thickness of the heat-insulating cake often reaches 30–40 cm. If these centimeters are taken away from the top and sides, then the room may turn out to be too low and small.

At the same time, the installation option with a lining of the crate under the rafters and laying insulation on it eliminates the appearance of cold bridges. If mineral wool or EPPS is inserted between the beams, then they themselves and the gaps that form over time in the heat-insulating layer near them will draw heat from the attic.

In order for ventilation in the under-roof space to be in accordance with the requirements of SNiPs, deflectors or other air outlets should be provided on the ridge.

The steam, together with the air currents, must rise to the highest point of the roof and leave from there completely outside. Moreover, this should happen without obstacles and as quickly as possible.

Before stuffing the membrane onto the rafters, you must first correctly calculate the thickness of the insulation. If the heat-insulating layer turns out to be larger than the size of the rafters, then you will have to build them up with bars. The main insulation material should be inside this frame, and not protrude from it.

Layer #2 - Vapor Permeable Membrane

In the upper part of the roofing cake being formed, there should be a material with high vapor permeability from the insulation to the street and high waterproofing in the opposite direction. The task of this membrane is not to prevent the release of steam from the thermal insulation, while not letting water and moisture into it, which can drip from a leaky roof.

The best material for this vapor-permeable layer, which also performs the functions of wind and moisture protection, is superdiffusion membranes. They are not clogged with dust and ice formed from condensate in severe frosts.

Laying of such membranes is carried out in horizontal stripes overlapping 10–15 cm from the top row to the bottom row from the outside. As a result, a single canvas should be obtained, if drops of water fall on it through the roof from the street, they would flow down without falling into the insulation.

The joints of the rows of the membrane from the inside of the attic are glued with mounting tape. It should be taken under the same brand as the breathable film.

The composition of the adhesive and the material of the membrane from one manufacturer are selected so as not to harm each other and to hold securely in the glued state for many years. If they are taken under different brands, then problems are possible.

Layer #3 - the main insulation

The thickness of the insulation is selected in accordance with SNiP 23-02-2003. For this, appropriate calculations are carried out, which take into account climatic conditions, the design features and roof structures, as well as the characteristics of the heat-insulating material and the inner lining of the attic.

It is not worth laying insulation with an excessively thick layer because of wasted money, and its too thin layer may not provide the required thermal protection

Manufacturers of thermal insulation give in the instructions for the material sold and post on their official websites detailed recommendations for determining this thickness. It is best to focus on these calculations.

Installation of insulation is carried out from the inside of the attic on top of the laid vapor-permeable membrane. If mineral wool is chosen, then it must be cut into pieces with dimensions 2-3 cm wider than the gaps between the rafters or the battens. The mineral wool should enter between them with a slight pressure and stay there due to the expansion.

EPS will have to be laid on top of the rafters, and not between them. The plates of this insulation are mounted end to end to each other. If you put them inside the rafters, like mineral wool, then through holes will appear in the heat-insulating layer.

Some craftsmen fill such gaps with mounting foam from a cylinder. However, this should not be done. This can lead to damage to the membrane due to the chemical reaction of the components of the sprayed foam and the material of the vapor-permeable film.

It is better to take 10–25 cm from the attic from above and from the sides to the crate with EPS, rather than get a layer of protection with through holes.

Layer #4 - vapor barrier film

On top of the insulation on the inside of the attic, a vapor barrier made of glassine or polypropylene or polyethylene film should be laid. The task of this layer is to keep water vapor out of the room into the insulation. It is laid in the same way as the very first vapor-permeable coating.

The joints of the vapor barrier should be given maximum attention - if you leave even the slightest gaps in them, then the steam will find these gaps and wet the heat-insulating material

In addition to the usual film, you can also take foil. The extra layer of foil will reflect most of the heat energy back into the attic, reducing heating costs. In this case, the installation of such a film is carried out with “aluminum” inside.

The vapor barrier is fastened with stapler staples or carnations with a wide hat. And in places where the film adjoins cables, pipes and structural elements of skylights, it should be additionally reinforced with a special one-sided tape with a heat-reflecting coating.

Layer #5 - ceiling sheathing

At the end of the attic insulation, the crate is stuffed under the cladding. It is made of bars with a thickness of 15-25 mm, so that a small ventilation gap remains above the vapor barrier.

Condensation due to improper vapor barrier and how to get rid of it:

When self-insulating the attic from the inside, when the roof is already covered, it is important to choose the right thickness of the heat-insulating material. And even more important - to carry out the correct installation without breaking the vapor barrier and wind-moisture insulation.

If the protective films on both sides of the insulation have holes, it will get wet and stop protecting the house from the cold.

Do you have experience with attic insulation from the inside? Or want to ask questions on the topic? Please comment on the publication, share your knowledge and participate in discussions. The feedback block is located below.