Invented back in the 17th century, attics have been popular among people in our country for several years now, turning a dusty attic into a room for a comfortable life. This expands the usable area of the house even at low cost.
Attics can be divided into summer and winter. This means whether the attic is insulated (or poorly insulated) or not. If you follow the advice experienced builders, then it is advisable to equip it a year after the construction of the house in order to avoid deformation and cracking of the material, which is inevitable due to the process of natural shrinkage of the house.
A more preferable option is to arrange the attic space at the stage of developing the house project. But this doesn’t always work out that way, so the attic arrangement is often done later. What options exist for this, and how it is technically implemented is the topic of another article, but we will talk about attic insulation, which is subject to more stringent requirements than for insulation of external walls due to large heat losses and a larger area of contact with the external environment.
Before you insulate your attic, you must thoroughly inspect it. internal structures. If necessary, they must be supplemented, strengthened, or somehow adapted to the installation of the selected insulation.
Choosing insulation for the attic
Today on construction market you can see a wide range of materials that will perfectly cope with the task. But when choosing, the question arises, which insulation is better for the attic. Generally speaking, the insulation must be reliable and of high quality.
“Cotton” insulation is a material that is obtained from mineral or organic fibers - stone wool, glass wool and so on. Cotton insulation fibers do not have closed pores. There is also a special class of foil wadding insulation, which is covered on one or both sides with a layer of aluminum foil.
“Foam” insulation are materials that are produced by foaming polymers, both in the usual way and by extrusion (extrusion). They are conventionally divided into materials with closed and open cells. This also includes the so-called liquid polyurethane foam, which is applied directly to the inner surface and in a few seconds increases in volume several times, filling all the voids.
A well-insulated attic roof usually consists of several layers, where there is not only insulation, but also a vapor barrier and a waterproof and windproof membrane.
Materials for attic insulation such as stone wool and glass wool are very popular in our country due to their resistance to high temperature and deformation, although more modern materials also do not stand aside.
Criteria for choosing a good thermal insulation material
- thermal conductivity indicators;
- volume and weight of insulation;
- maintaining shape stability;
- vapor permeability;
- flammability;
- soundproofing characteristics;
- durability.
A little more detail
THERMAL CONDUCTIVITY. Taking into account the specific location of the attic, this figure should not exceed 0.04 W/m°C. Modern manufacturers often indicate several parameters of thermal conductivity when different conditions operation - at temperatures of 10°C and 20°C and at two humidity categories - A and B. Taking this into account, the thickness of the attic insulation should be calculated as accurately as possible. And to do this, you can either turn to specialists, or you can figure it out yourself by turning to SNiP II-3-79 “Construction Heat Engineering”.
WEIGHT AND VOLUME OF INSULATION. In this parameter, insulation materials can differ significantly from each other. When choosing, do not forget that the roof truss structure must support the weight of the insulation. Unlike light insulation, heavy insulation can bear the weight of both the roof itself and snow in winter.
FORM STABILITY. This parameter is more relevant for pitched roofs with a large angle of inclination, where the insulation can slide and partially crumple under its own weight. This can also be observed during poor-quality installation, when the material slides, also forming bare spaces, and this, as practice has shown, leads to heat losses of up to 40%. Therefore, when choosing insulation, you must pay attention to how long and under what conditions the insulation will retain its geometric shapes. But you won’t find such a parameter as “shape stability” on the packaging, so you need to focus on a special pictogram indicating the specifics - “for pitched roofs.”
VAPTOR PERMEABILITY. Why does this question even arise? Moisture negatively affects the thermal insulation characteristics of materials, so it is necessary to protect it. To do this, there must be a vapor barrier on the inside of the insulation. To eliminate moisture that has entered the thermal insulation material, a ventilated air layer must be left between it and the outer (waterproofing) layer of the roof.
Vapor permeability is one of those indicators that can vary greatly from one type of insulation to another.
What are considered good or bad indicators? For example, “cotton” insulation has good vapor permeability, although, passing through them, steam turns into water, and, despite the fact that the fibers of such insulation are made with the addition of water-repellent additives to reduce wettability, part of the passing condensate may still remain, worsening thermal insulation properties. To avoid this, an additional vapor barrier layer is installed on the side of the room.
“Foam” insulation (especially with a closed cellular structure) allows virtually little vapor to pass through, but only foil insulation and glass are completely vapor-tight.
To avoid greenhouse effect, you need to properly arrange the internal air exchange even if you decide to use insulation made of mineral wool with good “vapor permeability” abilities, you need to design vents or an effective ventilation system. But most the best option will not rely on the vapor permeability of the insulation, but will organize a separate vapor barrier layer.
THE INDICATOR OF FLAMMABILITY OF A MATERIAL is important for ensuring a safe human life, because no one is immune from unfortunate accidents. Therefore modern building material should be as close as possible to “NG” - non-combustible materials.
In fairness, it must be said that at the epicenter of the fire and brickwork, both metal and reinforced concrete significantly lose their load-bearing capacity.
SOUND INSULATION CHARACTERISTICS are also important for a comfortable life. Even if no one lives in the attic above you, rain, hail and even strong wind may create discomfort for you. As for insulation, cotton insulation takes the lead here. Thanks to their fibrous structure, they perfectly absorb noise. But if you want to achieve the maximum noise-insulating effect, then it is best to use foam insulation together with cotton insulation.
DURABILITY usually depends on stability and water absorption.
As already mentioned, the arrangement of thermal insulation requires accurate calculations taking into account the climate in the region and the purpose of the building. But a person does not always bother himself with any calculations, doing everything according to the principle “whatever there is enough money for.”
Information for those who like to do things by eye
In this case, perhaps, it would be best to be guided by the principle that the more, the better (if, of course, the design can withstand). The most popular insulation in Russia today is basalt wool insulation. In a temperate climate, it will be sufficient if the thickness of the attic insulation is 18 cm. Although in regions with a warm climate, a layer of 10 cm will be more than sufficient.
But if you live in a colder region, then a 25 cm layer of thermal insulation will guarantee you warmth even preliminary calculations. And to eliminate cold bridges, the wool is laid in three layers, ensuring overlap at the seams. If the height of the rafter board is not enough, then counter battens are stuffed from the inside and the rafters are sheathed. From the inside, everything is lined with a board, under which a vapor barrier must be attached.
To retain heat inside, foil materials are often additionally installed. With all this, special attention should be paid to the vapor barrier, because to insulate the attic, you should not allow moisture to reach the heat insulator, and unwanted condensation under the roof will not give you pleasure.
Today, polyurethane foam is also popular, which makes it possible to obtain a monolithic layer of insulation without cold bridges, and the effect is achieved even with a smaller thickness of its layer. Polyurethane foam has the lowest thermal conductivity coefficient. In hot weather it prevents air heating, and in winter it prevents heat loss and the formation of icicles.
In terms of density, it is necessary to choose a material with indicators from 15 to 35 kg/m³.
When insulating an attic roof, do not forget about insulating its ends!
Even when insulating the attic, there are simple rules:
- the higher the requirements for thermal insulation material, the more expensive it is;
- when choosing a method for insulating an attic, you can use not one type of insulation, but two, so that the advantage of one material compensates for the disadvantage of the other;
- The choice will largely depend on the roof design.
But, according to experts, there are no exclusively “bad” or exclusively “good” thermal insulators, there is only their incorrect use.
The arrangement of attic rooms in private houses and cottages involves increasing the living space with a minimum of financial investments and costs of materials. Since the additional upper floor is intended for further use, then the logical action would be to take measures to insulate it.
Warming “pie”
Experts use various types insulation depending on the design of the building, the climatic conditions of the location of the building, and the financial capabilities of the owner. However, the layer-by-layer arrangement of the materials necessary for insulating the attic looks approximately the same (see):
- External covering.
- Counter-lattice.
- Waterproofing layer.
- Insulation.
- Vapor barrier with fixative.
- Decorative coating.
Depending on what is supposed to be insulated: the roof, walls, floor, the diagram may change slightly, but the principle of constructing the “pie” will be approximately the same.
IMPORTANT! When choosing insulation, you must independently or with the involvement of professionals make the optimal calculation for the quantity necessary materials. This will help to avoid a significant reduction in the height or linear parameters of the room due to the thickness of the “pie” layers.
Mineral wool
Using mineral wool will perfectly protect the room not only from cold or excessive heat, but also from noise. However, the disadvantage of the material is its high hygroscopicity, which necessitates the use of a waterproofing layer to increase moisture resistance.
When creating a thermal insulation layer for the roof, the thickness of the insulation for the attic can vary in the range of 15 - 20 - 25 cm, which depends on design features rafter system. In order for the mineral wool to fill the required space, the width of the canvas should be 2 cm larger.
Thanks to the use of thermal insulation, sufficient conservation will be ensured in the attic comfortable warmth, breathability, eco-cleanliness of the internal layers without the development of fungus, mold, and microbes.
Builders consider the use of extruded polystyrene foam to be one of the most profitable materials both in terms of costs and in preventing heat loss.
IMPORTANT! Before using EP, you should check the treatment of the construction product with substances that increase fire resistance, or ensure their presence in the constituent components.
EP is easy to install and follows the same installation steps as mineral wool. When determining how thick the penoplex should be, it is necessary to know the parameters of the space to be filled in order to take into account the location of the material.
The fact is that to insulate the roof or walls of an attic room, a thickness of 7 - 10 cm will be sufficient. After laying and securing the polystyrene foam sheets and carrying out the interior finishing, we can say with confidence that the heat on the upper floor will be fully preserved .
ADVICE! If the electronic signature is intended to be used in regions with low temperatures, then for greater confidence in thermal insulation, experienced experts recommend laying two layers.
Such actions will pay off in energy costs for heating not only the attic, but also the rooms whose ceilings serve as the floor of the upper room.
Advantages
Among the positive properties are:
- The tightness of the slabs.
- No delaminations.
- Maintaining thickness due to the fact that the material does not sag.
- Good sound insulation.
- Low price.
- Lightness, due to which the pressure on the structure is insignificant.
TO negative aspects The choice of polystyrene foam for attic insulation includes its weak vapor permeability and low thermal conductivity.
Basalt insulation
For basalt insulation characterized by such features as:
- Resistance to mechanical deformation.
- Noise insulation.
- Hydrophobicity.
- Energy saving.
- Non-flammability.
- Durability.
When calculating the optimal thickness, it is necessary to take into account all its characteristics in order to select a layer sufficient for insulation. Typically, for any of the Russian regions, the best thickness is considered to be 150 - 200 mm. For areas with severe frosts a two-layer laying of basalt slabs will be required.
Is it worth insulating the attic?
The question is relevant, since the cost of any of the above or other insulation materials cannot be called low, the costs will definitely be there. But if the owners of the house have a desire to create another living space while simultaneously insulating the roof (there is no way around this point), and also spend time in a cozy and warm space, then it is better to insulate the attic. After determining how thick the insulation layer should be, all that remains is to purchase the selected material and begin to carefully carry out the work.
Successful and economical solutions for preserving heat in the attic!
Two options for arranging the attic.
Today, the attic has lost its former purpose as an attic space and has become an additional, multifunctional room. If desired, you can equip it with a billiard room, a children's room, an additional bedroom or a spacious bar. But for this it is necessary to create a suitable microclimate: waterproof and insulate the attic from the inside with mineral wool with your own hands.
Roof insulation with mineral wool
This area is insulated first, not only for purely logical reasons, but also in order to slightly delay the insulation of the floor and walls. This is done in order to allow the wood to dry for as long as possible. Otherwise, the moisture it releases may settle on the insulation and slightly weaken its inert properties.
The thickness of mineral wool for attic insulation is 20-25 cm.
You need to start the insulation process from the outside (the case when the house is just being built). A vapor barrier is laid on the pre-prepared sheathing (boards perpendicular to the rafters, nailed on the inside) and blocks are laid out. The thickness of the mineral wool for insulating the attic should be 20-25 cm. If the thickness of the rafter beams is insufficient, you can do the following:
- or nail 50 mm blocks parallel to the support (on the rafters themselves) and lay stone wool in two layers, one on top of the other;
- or make a counter-lattice from 60-120 mm bars/boards (this way we will leave a gap between the mineral wool and the external insulation), after which we line the second layer of insulation perpendicular to the inner one;
The necessity and peculiarity of using this material is that it allows wet vapors to pass through only one direction (outside) and keeps moisture from a leaking roof from getting inside. The insulation must be secured with screws or a construction stapler, leaving very little sagging (so that the layer does not deform and lose its qualities as a result of tension during temperature changes).
When connecting sections of waterproofing, maintain sufficient overlap (about 15 cm), which will protect against leaks and the formation of gaps that release heat to the outside.
We block the cold bridges.
The intersecting layers are secured together with special double-sided adhesive tape or reliable construction tape. You can make a slight bend on the outer rafters and once again secure the edges of the film with stapler staples. Then a counter-lattice is applied to the waterproofing layer, creating a gap between the roof and the insulation layer.
The approximate thickness of this layer should be 5 centimeters. Its function is ventilation and removal of moisture accumulated under the tiles. It is important that at the highest point of the roof (ridge) a small cavity is left, not filled with insulation or timber. Through it, moist air will leave the building, passing from under the edge of the roof up and out again.
If the house has already been built, when insulating the attic from the inside with mineral wool, the insulation is fixed using a construction stapler (on the side surfaces of the rafters). A five-centimeter gap is also maintained between the film and the roof cladding for ventilation. Afterwards, with a margin of width of 10-15 mm (relative to the distance between the rafters), the thermal insulation is cut and lined.
Insulation of the attic with mineral wool from the inside ends with fastening to inner side rafters (or counter-lattice) of the vapor barrier layer, which will not allow mineral wool soak in moisture. Another row of beams is fixed on top, on which chipboard panels or directly interior decoration premises.
Insulation of attic floors and walls
Mineral wool must be protected from moisture.
This process is very similar to roof insulation:
- We lay a vapor barrier or a layer of bitumen-impregnated paper on the boards between the rafters, which will keep mineral wool particles from slipping through the support and getting into the air of the lower floors;
- then we line the heat insulator itself in two layers with a total thickness of 15-20 cm;
- If necessary, we nail additional blocks on top to increase the height of the rafters. We place a waterproofing layer on them and cover everything with boards (subfloor).
Also, if possible, it is recommended to lay the vapor barrier overlapping the walls downwards (that is, the ends are lowered along the walls of the lower floor and plastered). This will prevent any steam from penetrating into the mineral wool and damaging it. The walls, if necessary, are insulated in the same way. Only in this case, depending on their density and thickness, the thermal insulation layer is reduced and the external waterproofing film is removed.
Which mineral wool should you buy?
When there are so many similar products on the market, it becomes difficult to determine where the best mineral wool for the attic is produced and which one is worth choosing, and which one is clearly overrated. It seems that there is some kind of “leader”. But the truth is that most large manufacturers are approximately at the same level in quality and produce cotton wool with the same thermal conductivity coefficient. You get about the same thing for the same price in completely different packages. Therefore, it is only important to remember that glass wool in blocks is considered better than rolled wool, and vacuum packaging hold 2 times the size of the final product.
It is also worth saying that the seller of a non-core store can voice a more unbiased opinion about which mineral wool is better for the attic and which for the walls of the lower floors than a consultant from one of the manufacturing companies. Therefore, before making a final decision, compare the parameters of at least three options from different companies and choose the best one.
That's all! We looked at the question of how to make a former attic space warm, and discussed the general insulation technique. We took into account all the details and are now almost ready to get to work. All that remains is to watch the practical guide on insulating an attic from the inside with mineral wool in the video and get answers to all the remaining questions in it.
If the house has an attic, then it needs to be insulated. This must be done to maintain heat in the house. The attic can also be used as a living space, expanding the usable area. Insulation of the attic must also be done in order to preserve the roof material and its elements, create coziness, microclimate and comfort in the living space.
It is important to correctly calculate the thickness of the material for. To do this, you need to know within what limits it varies temperature in your area and the properties of the material you have chosen for thermal insulation.
When insulating an attic, the thickness of the insulation is an important point.
What is used to insulate an attic roof?
To insulate the attic, glass wool, basalt (stone) wool, and extruded polystyrene are used. The material for insulation must not allow or absorb moisture, be easy to use, fire resistant, preserve previous dimensions in progress operation, i.e. don't sit down. It must be remembered that attic insulation does not create heat, but is intended to preserve it.
In the attic, three structures need to be insulated: the walls, the roof slopes and the attic floor itself. To insulate each structure, the thickness of insulation required is different, since the side walls retain heat better than the ceiling of the attic.
We take into account that different designs require different insulation . Thus, it is better to insulate the slopes of the attic roof with a special glass wool intended for pitched roofs. You can read this on the packaging.
We use basalt (stone) wool in the form of slabs, so it does not break or deform, and does not shrink. It is suitable for roof insulation.
Whatever material you choose should be tiled as this will prevent it from rolling and will make it last longer.
Thermal insulation properties of various materials
How to calculate the thickness of attic insulation?
To carry out the operation of calculating the thickness of the material for insulation you need to know two quantities:R— thermal resistance and λB is the thermal conductivity of the material. Index B indicates that the material can be used in a damp environment. Thermal resistance R depends on the climate of your area, and you will find the thermal conductivity of the insulation printed on the product packaging or in the documents accompanying it.
Thermal resistance table (R)
Table of insulation thickness depending on the city
You can also use a map of thermal resistance for some cities in Russia, posted on the Internet, and a table of thermal conductivity of materials. If your city is not listed in the table, use the map to look for a nearby city whose thermal resistance is indicated in the table.
The thickness of the insulation is calculated using the formula R λB.
An example of calculating the thickness of material for insulation.
As we see, the choice different materials entails different thicknesses of insulation and for different floors you need insulation of different thicknesses. All you have to do is ask about prices and choose the right insulation.
The attic is a room equipped under the roof, used for permanent residence or just to have a good time. Attics are widely popular in many countries, but for a comfortable arrangement they are very important has the equipment of a thermal insulation system that prevents heat loss through roof slopes.
Basic requirements for insulation for an attic roof
To insulate the roof of an attic, various thermal insulation materials can be used, when choosing between them, pay attention to the following characteristics:
- low thermal conductivity;
- high frost resistance and resistance to defrosting;
- resistance to significant temperature fluctuations;
- low hygroscopicity, minimal moisture absorption;
- non-flammability;
- long period of operation.
On the other hand, when choosing insulation, factors such as the slope and shape of roof slopes, climatic and weather conditions terrain, the purpose of the attic being equipped, etc. Not only the preference for one material or another depends on such nuances, but also what density of insulation is needed for the attic, the thickness of the insulation mansard roof and some other parameters.
Basic materials for arranging thermal insulation of the attic
The choice of insulation materials on the modern construction market is quite large, however, the following are most often used for thermal insulation of attic roofs:
- mineral wool;
- foam;
- polyurethane foam.
Each of these materials has its own characteristics, advantages and disadvantages, which are worth dwelling on in more detail. Let's figure out which insulation is best for an attic roof in order to make the right choice.
Mineral wool - density and thickness of mineral wool
Mineral wool is perhaps the most common insulation material for attic roofs due to its low cost and good thermal insulation qualities. In addition, the advantages of this material are also fire resistance, good breathability and low hygroscopicity. On the other hand, the thermal insulation characteristics of mineral wool are significantly reduced when wet, which makes it mandatory to equip it with waterproofing and vapor barrier membranes.
Mineral wool has several varieties:
- glass wool;
- slag;
- basalt or stone wool.
Glass wool is made from the finest glass fibers 5-15 microns thick and 15-50 millimeters long. It has an elastic and durable structure, and requires great care when working: to avoid irritation, when laying it, wear a protective suit, gloves, goggles and a respirator. Resistant to temperatures from minus 60 to plus 450-500 °C.
Slag wool, made from blast furnace slag, contains fibers 4-12 microns thick and approximately 16 millimeters long. This material can withstand heating up to 300 °C, but is ineffective when arranging thermal insulation of the attic due to its high hygroscopicity. In addition, slags with residual acidity can have an aggressive effect on metal surfaces, which is also a significant drawback. The disadvantages of slag wool are also its fragility and “prickliness”, which creates inconvenience when working with it with bare hands.
Basalt (stone) wool is made from gabbro-basalt or diabase with composite and binder additives. Its fibers have approximately the same dimensions as those of slag wool. In terms of technological characteristics, this material is superior to all other types of mineral wool, and therefore is especially often used for thermal insulation of attic roofs. Stable when heated up to 600 °C (some types - up to 1000 °C). When using this type, the elasticity and density of mineral wool for attic insulation is sufficient so that the material does not wrinkle or settle when installed on slopes.
As for the required thickness of mineral wool for insulating an attic, it largely depends on climatic conditions, averaging 15-30 centimeters. It is clear that in regions with colder and more humid climates, the thickness of the insulation for the attic roof should be relatively greater.
Foam plastic
Foam plastic is a modern thermal insulation material based on polystyrene foam. Its structure is hardened polystyrene foam, inside of which there are many air bubbles.
The advantages of polystyrene foam are light weight, excellent thermal insulation characteristics, low hygroscopicity and good sound insulation properties, which, combined with an affordable cost, make it one of the most preferred materials for insulation. At the same time, the disadvantages of polystyrene foam, which should be taken into account when arranging the attic, are flammability, instability to high temperatures and exposure to ultraviolet rays, as well as low strength.
To improve performance characteristics Some manufacturers treat foam products with fire retardants, which increases their service life by several years, which makes attic insulation with foam economical.
It should also be said about what layer of insulation is needed for the attic if this material is used. Required thickness for most climatic zones it is 15-20 centimeters, but in frosty regions it makes sense to increase it to 25-30 centimeters.
When arranging thermal insulation for an attic roof made of foam, it is important to ensure good ventilation of the under-roof space, since this material is not “breathable”. Otherwise, this may lead to condensation, mold and putrefactive processes.
Polyurethane foam
Polyurethane foam is a polymer insulation, which is a type of foamed plastic with a cellular structure. The cells are filled with a gaseous substance, which determines the effective thermal insulation properties of this material.
The advantages of polyurethane foam are versatility, low flammability, lack of hygroscopicity, resistance to aggressive chemical influences, low thermal conductivity and durability. Although in terms of thermal insulation characteristics it is slightly inferior to foam plastic and mineral wool, it is several times longer than them in terms of service life.
Polyurethane foam insulation is available both in the form of slabs and in the form of sprayed liquid mixtures. Last option is the most versatile and effective: it can be applied to any material, while closing all the cracks and gaps.
It should be noted that if in the case of tiled materials the calculation of insulation for the attic may present certain difficulties, then when spraying liquid polyurethane foam no special calculations are required. The whole process can easily be carried out with your own hands in a short time - all you need is the presence of a thermal insulation composition and equipment for spraying it.
Another important advantage is that liquid polyurethane foam is sprayed without seams or joints, completely repeating the complex shapes of inclined and other surfaces. This results in significantly more effective thermal insulation. Therefore, if we talk about what thickness of insulation should be in the attic, then a layer of 10-15 centimeters is usually sufficient.
Tiled forms of polyurethane foam are also used for insulating attic roofs, but are somewhat less convenient and practical.
Other types of insulation for attic roofs
Along with those listed, other materials are sometimes used for thermal insulation of attic roofs, although their prevalence is not so great.
For example, in some regions it has not lost its importance old method– insulation with felt. In addition, in recent years New types of effective thermal insulation materials, which appeared on the construction market relatively recently. This includes, for example, ecowool and modern fiberglass insulation. It is also worth noting that, along with the considered types of insulation, their foil varieties are often used, the cost of which is somewhat more expensive.
It is clear that the calculation of attic insulation may have certain features depending on the type of insulation used and a number of other factors.
So, for example, the answer to the question - how thick should the attic insulation be - can be broadly formulated as follows:
- the greater the thermal conductivity of the material, the greater the thickness of the thermal insulation layer should be;
- for areas with a milder climate, thinner insulation is required, for more severe climatic zones - vice versa;
- large number joint areas and seams contributes to heat loss, necessitating the need for greater thickness of insulation.
The correct choice of material for thermal insulation and well-made calculations serve as the basis for ensuring thermal comfort in the attic room, literally contributing to a warm atmosphere in it at any time of the year.