A very large percentage of losses occur through the ceiling of the upper floor with an insulated attic. This is due to the fact that heated air always moves upward. One of the effective ways to prevent heat loss is to insulate the ceiling with foam. When used in a private house, insulation has many advantages.
Advantages and disadvantages of polystyrene foam
The material is an accumulation of styrene balls, inside of which there is air. Air and inert gases are the best insulation materials in the world. The more air in the material, the better its thermal insulation properties. The advantages of polystyrene (polystyrene foam) include:
- Low thermal conductivity. The main characteristic of a heat insulator is its ability to conduct heat. The lower it is, the warmer it will be in the room. The thermal conductivity of the foam is about the same as that of mineral wool or extruded polystyrene foam.
- Low cost. Repairing or building is always a costly undertaking. Polyfoam is an effective material that does not require large financial investments.
- Light weight. The mass of expanded polystyrene allows you to use it to warm the ceilings from the inside without any problems. The material holds well on a horizontal surface. The smaller the mass of the insulation layer, the easier it is to fix it and the less likelihood of it falling off during operation. Light weight during events in a private house also reduces the cost of material delivery.
- Easy installation. The characteristics of the heat insulator allow even non-professionals to do the job. To insulate the ceiling with foam, you do not need to apply a lot of effort.
- Safety. With independent insulation in a private house, it is important to ensure the safety of the manufacturer and the residents in the future. The structure of the foam is such that even when destroyed, it scatters into balls of a sufficiently large size. They cannot harm a person. This compares favorably with polystyrene, for example, from mineral wool, which requires the use of masks and gloves.
The positive qualities of the foam allowed him to firmly establish himself in the market of building materials. But he has his own characteristics and limitations. Polystyrene insulation has the following disadvantages:
- Styrene balls do not absorb water, so the foam has a fairly low degree of water absorption. The difficulty lies in the fact that water can enter the space between the balls. Under normal conditions, this does not lead to problems, but if the ambient temperature drops, destruction will occur. The bond between styrene balls does not have high strength. When it turns into ice, water expands, affecting individual particles of the material. With the simultaneous action of water and cold, the foam simply crumbles.
- Low fire safety. Polystyrene is not resistant to high temperatures. Now manufacturers are introducing special additives that make polystyrene a low-combustible material, but the problem remains.
- Low strength. This disadvantage is important when warming the floor. For installation on the ceiling from the inside of the room, it is not necessary to use durable materials, the mass becomes more important here. Insulation from the side of the attic with foam is also possible, but because of its strength it is placed between the logs or under a strong reinforced cement screed.
- Unnatural origin. Also a feature rather than a disadvantage. Insulators of natural origin, such as sawdust or expanded clay, have low efficiency. Another type of natural insulation is ecowool. The material is effective, expensive.
The last two points are not serious drawbacks when insulating the ceiling in a private house, so we can say that the foam showed itself as an excellent heat insulator with a score of 5: 2.
Warming Methods
Do-it-yourself insulation of the ceiling with foam can be done from the outside and from the inside. The option on the cold side provides greater efficiency and is scientifically correct. When insulating in a private house, it is best to insulate the ceiling of the upper floor from the attic.
This method is difficult if insulation is carried out in an apartment building. In this case, insulation from the inside is almost the only possible option. Warming in the apartment is carried out not only for the purpose of protection from the cold, but also from noisy neighbors.
If you insulate the ceiling with foam inside, you can significantly reduce the noise level and create favorable conditions for relaxation.
As already mentioned, the combination of water and polystyrene is undesirable, therefore, when laying, two additional layers are provided: from the side of the cold air - waterproofing, and from the inside of the room vapor barrier.
The order of work when warming from the attic:
- cleaning the surface from debris, dust and dirt;
- leveling if necessary;
- vapor barrier;
- lag laying (if needed);
- polyfoam laying (it is necessary to provide a small gap between the insulation plates or between the insulation and logs, the foam expands slightly after installation);
- waterproofing;
- screed pouring (for the method without lag) with laying of wire reinforcement with a diameter of 3-4 mm;
- clean floor.
The last point is an optional step. As a flooring in the attic, you can leave a cement screed.
Thermal insulation of the ceiling in a private house from the inside is performed in the following order:
- ceiling cleaning;
- installation of the frame (wooden or aluminum profile, the stage is optional);
- fixing foam sheets;
- vapor barrier;
- covering of a ceiling.
Sheet fastening
Thermal insulation of the ceiling with foam provides two ways of fixing the material. When laying from the side of the attic, it is enough to simply lay out the sheets, special fixing is not required. If inside mounting is provided, special attention must be paid to the mounting.
You can hold the material from below on a horizontal surface in two ways:
- fastening with special nails to the frame;
- adhesive fastening.
With nail fastening there are problems.
When installing the insulation in the house on glue, you need to remember that the foam is not resistant to chemical solvents.
Polystyrene adhesive should not contain:
- acetone;
- alcohol;
- formaldehydes;
- aggressive resins;
- various solvents.
In the presence of these components, the adhesive composition will corrode the insulation and work efficiency will decrease.
In order to correctly perform additional thermal insulation in the house, you need to pay attention to such surfaces as: the ceiling of the upper floor, the ceiling on the balcony, the ceiling of the attic.
The thickness of the foam for insulation is accepted in the range of 100-200 mm. 30-50 mm is enough for sound insulation.