Methods for calculating the amount of insulation for the roof

The thermal insulation of the roof significantly affects the formation of the microclimate in the living room. It affects the temperature regime and fire safety, increases sound insulation, protects against dangerous fungal infections, rodents. For this reason, you should take a responsible attitude to the selection of material, as well as correctly calculate the insulation for the roof.

Basic requirements for materials

Any type of roofing insulation should be:

• vapor permeable;
• durable;
• resistant to mechanical damage;
• environmentally friendly;
• durable;
• sound insulating;
• fireproof.

Particular attention should be paid to thermal conductivity and moisture absorption. The latter should be low so that moisture does not accumulate in the material, and the roof breathes. The lower the first indicator, the more effective the thermal insulation.

Roof material thickness

Calculations depend on the climatic zone of the location of the construction site and the thermal conductivity of the material selected as insulation. With a lower thermal conductivity of the insulation, the heat will be retained more, the layer will need to be thinner. Clear requirements for thermal protection of structures in order to save energy, ensure optimal parameters of the microclimate of the premises are set out in SNiP 23-02-2003 "Thermal protection of buildings".

You can calculate the thickness of the thermal insulation layer using the formula:R = p / kwhere R - thickness, k - thermal conductivity.

The last parameter is determined by the selected type of material. All insulation coefficients are taken from standard tables.

If you need to calculate the thickness of thermal insulation, consisting of several layers, you need to use the formula: R = R1 + R2 + R3.

Calculation of the amount of materials

Before starting work, you should calculate the insulation for the roof. To this end, you need to measure the total surface area of ​​the roof, and then calculate the required amount of material and add a small margin.

The calculation of the volume of insulation for the roof is done as follows:

1. The surface area must be divided by the amount of material (in m2) contained in one package.
2. The previous result is multiplied by the number of layers.
3. The result of the count is the number of boxes required. When the resulting value is not an integer, it should be rounded up and increased by 10%.

The area of ​​a pitched or flat roof is easy to calculate. If the appearance of the roof is complex, the entire roof surface is divided into simple shapes, after which the individual areas are calculated and summed up.

Roof insulation methods

As a rule, the roof is insulated in two ways: between the rafters and above the rafters.

Between the rafters

The option is possible when the height of the rafter leg is sufficient for the installation of heat-insulating material of the required thickness. At the same time, the living space in the room is almost not lost, but cold bridges may appear in the event of improper installation of thermal insulation.

Over the rafters

The most effective version of roof insulation from the point of view of thermal protection requires qualified roofers and expensive materials.Insulation is laid directly on the wooden flooring and vapor barrier film installed on the rafter system. Then, a diffusion film, lathing, and roofing are mounted. Since the surface of such a roof is covered with a continuous layer, the risk of cold bridges and condensation is eliminated.

Do-it-yourself roof insulation

Flat roof can be insulated from the outside and from the inside. First, do external insulation. With a low efficiency of the latter, an internal one is carried out.

Thermal insulation of a flat roof is performed in compliance with a certain technology:

1. The main overlap is covered with a vapor barrier film, the joints are sealed with tape.
2. Mineral wool or foam, which is cheaper, is used as a heat-insulating material. Plates are laid tightly.
3. For the purpose of waterproofing, roofing material is used.
   
4. The waterproofing layer is covered with mastic.
5. Additional sound insulation is provided by a layer of expanded clay.

Internal insulation is carried out if the ceiling height allows.

The works are performed in the following sequence:

1. A crate is mounted on the ceiling.
2. Place a vapor barrier coating.
3. Insulation is laid (mineral wool, expanded polystyrene).
4. Decorated with decorative panels.

General principle of insulation pitched roof is similar with the exception of some nuances:

1. The rafters and the space between them are covered with a vapor barrier film. The material is fastened with a stapler.
2. Thermal insulation is made with mineral wool slabs. The latter are tightly laid between the beams, the insulation is fastened using a nylon mesh, a wooden lath.
3. The next stage is additional vapor barrier. The joints of the film are sealed with tape.
4. At the end, they are finished with clapboard, chipboard or drywall.

In low-rise construction, a pitched roof is often made, since it provides better hydro and thermal insulation, its design allows you to equip an attic in the form of an additional room.

Correctly performed roof insulation allows you to keep the house as warm as possible in winter, and protects from the heat in summer. The cost of electricity used to cool or heat a room is significantly saved.