Insulation of the attic, attic with polyurethane foam: how to make and foam

Insulating the attic with polyurethane foam (PPU) has great advantages, since it is one of the best materials in terms of protection from cold and noise. Even a small layer of 80 mm replaces 160 mm of polystyrene, 200 mm of mineral wool and more than 500 mm of wood. However, it must be taken into account that the mixture is prepared and poured using special equipment. How to do this at home is described in detail in the presented article.

Pros and cons of polyurethane foam

When planning insulation of a PPU roof, you should evaluate the advantages, disadvantages and features of the material. This is a polymer organic plastic that contains small pores with air bubbles that provide protection not only from cold, but also from noise.

A characteristic feature is that polyurethane foam for roof insulation is produced directly during installation. To do this, the components are mixed with water in equal quantities and supplied to the work site through a hose using a special compressor. Thus, it will not be possible to complete the work without the use of equipment.

At the same time, insulating the attic with foam provides many tangible advantages:

• low thermal conductivity provides maximum thermal insulation, even better compared to polystyrene, mineral wool and wood;
• the composition does not absorb moisture and, as a result, does not rot or become moldy;
• Ceiling insulation with polyurethane foam is especially good - the material is not dense, it is required in small quantities, and therefore creates minimal load on the structure;
• high fire safety class - G-2;
• you can create a layer of any thickness with an accuracy of several millimeters;
• insulating the roof from the inside with polyurethane foam provides protection not only from cold, but also from noise;
• there is no need to use hydro- or vapor barrier;
• long service life - from 30 years.

However, there are also disadvantages. As already mentioned, you cannot prepare the mixture yourself, since this requires a compressor station. In addition, it is worth considering that polyurethane foam is not resistant to sunlight. However, this is not a problem since the material is coated with a finish that provides complete blackout.

Preparation before insulation

In order to properly insulate an attic with polyurethane foam, it is necessary to prepare the surface and the room. First, remove all items and cover the windows, along with window sills and slopes, with polyethylene film. The fact is that drops of polyurethane foam adhere very firmly to the surface, and even if you start cleaning right away, it will be quite difficult to remove them.

The previous coating, including old paint, is removed. If the roof is old, the joists should be partially replaced and all elements should be treated with an antiseptic. When the roof insulation with polyurethane is finished and the material hardens, access to them will no longer be possible. The last step is to remove debris and dust so you can work with a clean surface.

Before starting installation, prepare equipment and materials:

• hoses;
• containers;
• compressor station;
• hoses;
• mask;
• gloves.

Step-by-step instruction

Insulation of the attic from the inside with polyurethane foam is carried out in several stages:

1. After preparing the surface, you will need to install logs (if there are none). They will not only strengthen the structure, but also perform leveling when filling the mixture.
2. Attic insulation with polyurethane foam is carried out using a compressor station, which must be raised and assembled directly on the roof.
3. Knead the mixture according to the instructions, keeping the ratio of components to water 1:1.
4. Spray the first layer, the thickness of which is 15 cm.
5. Roof insulation by spraying polyurethane foam is carried out in several stages. Moreover, each subsequent layer is applied only after the previous one has completely dried.
6. When the last layer has dried, you can install the interior finishing. It is laid along the joists or the sheathing is pre-installed.

It is important to understand that in order to foam a roof with polyurethane foam, you need not only special equipment, but also some experience. It is especially important to maintain proportions and control the color - if it darkens, this indicates a violation of the ratio. You can work in the warm season - the minimum temperature should be +10°C.

When you plan to insulate an attic with polyurethane, you need to calculate the thickness of the layer in advance. For example, for regions of the middle zone the minimum requirement is 150 mm, while for Siberia - from 250 mm. During work, you need to immediately lay a layer of the required thickness, because it will be too late to return even after a few minutes - the composition dries out quite quickly.