Heat losses through the attic floor and the roof of a heated building can reach 30%. Therefore, the need to save energy forces homeowners to seriously think about quality insulation. Some owners solve this issue by installing thermal insulation on the floor slab. But if you do this from the inside, then the efficiency will be extremely low, because as a result, the dew point is shifted and, as a result, moisture may stagnate inside the ceiling.
If the heater is laid on the stove from above, then, in the case of a pitched roof, you simply can not use the attic for the pantry or for other household and household purposes. In order for the attic to remain a full-fledged additional room, you will have to make reinforced screed on the insulation or lay strong sheet material on the logs, which will significantly increase the cost and weight load on the ceiling.
At the same time, it is desirable that the material for roof insulation is inexpensive, effective and durable. To reduce costs, insulation work is best done by yourself. Therefore, when deciding how to insulate the roof of a private house, the level of complexity of the installation technology should also be considered.
Types of insulation used
The most common materials used for roof insulation in private homes and farm buildings:
- crushed expanded clay;
- Styrofoam;
- polystyrene foam;
- polyurethane foam;
- mineral mats;
- flax fiber;
- ecowool.
Expanded clay - inefficient heat insulator with a fairly high coefficient of thermal conductivity. To properly insulate the roof, you will need to pour a layer of crushed granules 3-4 times thicker than a mineral wool or foam coating. As a result, efficiency is low, and the cost of acquiring material is high.
Polyfoam and expanded polystyrene can be mounted only on a separate inner lathing of the roof, which leads to additional work and financial costs. In addition, it must be borne in mind that the foam is a combustible material and the rules prohibit its use as a heater for residential buildings.
Slabs made of extrusion PPP do not spread combustion, but are too expensive to use in the attic. Therefore, such materials can be used for insulation only if you do not have other alternatives.
Polyurethane foam - excellent durable insulation, but costs up to 1200 rubles / m2. For its application, special compressor equipment is required, and therefore you will not be able to carry out the installation yourself.
After completing the work, the rafter system of the pitched roof will need to be sewn up with sheet material, which will increase the cost of insulation to a prohibitive value. Not much cheaper will cost and the use of sheet PPU, supplied in the form of rolls. You will save on installation costs, but polyurethane foam in the form of finished products always costs more than the sprayed mixture.
There are 3 types of mineral wool, which can be used as insulation:
- slagged;
- glass wool;
- basalt fibers.
The first two materials They are inexpensive, but have a very limited service life, because they are caked for 15-20 years and simply disintegrate into dust. They are hygroscopic and able to accumulate moisture, dramatically losing thermal insulation properties.
If not for a higher price, then determining what to insulate the roof in a private house, we could say that basalt mats - perfect thermal insulation. They do not absorb moisture, do not burn and are so hard that you can even walk on them.
Linen - Natural, environmentally friendly, durable insulation, but so expensive that it is simply not available to most developers. Ecowool, unlike him, is very cheap, but after 10 years it will shrink, compress and stop keeping heat in the house.
Output: the best and most affordable materials for roof insulation can be considered basalt fiber mats and extruded (extruded) polystyrene foam. Conventional formative PPP is not recommended.
Flat roof insulation
The design feature of flat roofs is the presence of a strong reinforced concrete floor and a surface layer of hydraulic insulation. The attic is usually absent, the insulation is placed on a stove or an existing waterproofing carpet. After this, geotextiles are laid and poured with a ballast layer of fine stone chips, coarse sand and bitumen.
Since the thermal insulation on both sides is closed from external access and the load-bearing capacity of the plate is high, any material, even combustible polystyrene, slag and glass wool, can be used for its construction. However, it is better to opt for a more durable insulation, since replacing such a coating in 10-15 years will require significant financial investments.
It is best to immediately spend more and use basalt mats or slabs from extruded PPS. Such a flat roof will not require repair for a very long time.
Sloping roof of a residential building
The choice of insulation with a pitched roof largely depends on the use of the attic and the financial capabilities of the owner of the house. If you can spend money, then invite specialists to blow the rafter system and the inner surface of the roofing material with foamed polyurethane foam, followed by sheathing with sheet material.
In this case, the attic can become an additional warm room and can be used for any purpose. The best price option would be laying mineral wool basalt mats or polystyrene plates on the floor surface.
When installing the attic, solving the issue of roof insulation can combine 2 methods. The walls of the attic should be made frame by placing a heater inside them, and the rest of the ceiling, outside the room, simply covered with insulating material. If the attic is already there, then its walls will have to be sheathed with insulation from the outside, which is not always convenient and affordable.
It is not recommended to use expanded clay granules, fire hazardous polystyrene, glass-, slag- and ecowool for insulation. These are inexpensive and affordable materials, but they are short-lived and will become ineffective in a few years. Wet cotton quickly coalesces (is compressed) and comes into complete disrepair.
Roof insulation of household and domestic buildings
In most private areas, in addition to the residential building, there is a garage, a bathhouse, a wooden blockhouse for a guest house or workshop. Their roofs can also be insulated, but the operational and design features of each building should be taken into account.
The bathhouse. The presence of a boiler or furnace for heating a steam room refers the bathhouse to the category of fire hazardous buildings. Therefore, the use of polystyrene for roof insulation is strictly prohibited. In addition, the steam room and the washroom - rooms with high humidity and any heat-insulating wool will become worthless pretty quickly.
The best thermal insulation for a freestanding bath are mats or rolled material from fluffy basalt fibers. He is not afraid of moisture, an open flame and will last 50 years.
Garage. The operational feature of the garage is that it is not necessary to maintain the temperature above + 5 ° C. Therefore, the thickness of the insulation layer can be reduced by 3 times. In this case, the use of cheap expanded clay can be an effective way. If the garage is attached to the house and is heated, then its roof is insulated using the same technology as the whole building.
Wooden blockhouse. The main requirement for the insulation of the roof of any log house is the use of non-combustible materials. Therefore, the use of foams, linen and ecowool is unacceptable. You can choose mineral wool or non-combustible, but expensive, polyurethane foam. The requirements for thermal resistance of the material are determined by the accepted temperature of the indoor air.
Methods of installation of insulation
The presented insulation materials differ from each other in their structure, mechanical and physical characteristics. Accordingly, the methods of their installation are also different.
Expanded clay. Before filling expanded clay granules on the surface of the floor should be installed logs. This is an ordinary board with a thickness of 40-50 mm mounted on an edge. The insulation is poured between the lags and covered with a durable sheet material on top.
Polyfoam and expanded polystyrene. These materials are quite durable, but have insufficient wear resistance. In order to avoid the formation (over time) of gaps at the joints, the insulation should be laid in two layers.
So, for thermal insulation of 60 mm, you need to buy foam plates 30 mm thick and when laying the material of the second layer should completely cover all the joints of the first. On the surface of the laid insulation it is necessary to perform a cement screed reinforced with a metal mesh.
Polyurethane foam spraying. Work is performed using special pneumatic equipment. Thermal insulation is applied to the rafter system and the inner surface of the roof, forming a continuous waterproof coating. After spraying, the insulation is sewn up with a hard sheet, for example, plywood or OSB.
When using rolled PPU, you just need to beat the rafters and the crate with insulation. No additional coating is required, unless this is due to aesthetic requirements.
Mineral wool. Mineral wool insulation is supplied to the market in the form of mats and rolled materials. As when laying on the attic floor, and when placed inside the rafter system, the thermal insulation of mineral wool must be waterproofed and sheathed on the outside with sheet material. As well as polystyrene, these materials should be laid in 2 layers with overlapping joints.