How and with what to insulate the attic of a wooden house

It's impossible to fully insulate a house by focusing only on its walls. Both the floor and the attic will need to be insulated. This issue is especially acute for the attic. We all remember the law of physics that states that heated air has a lower specific gravity than cold air. That's why it always rises.

The same thing happens in a house. Warm air rises toward the attic, while cold air concentrates closer to the floor. Therefore, if the attic isn't properly insulated, 30% of the warm air will escape unimpeded.

Next, we'll discuss the specifics of insulating the attic of a wooden house, the materials needed, and how to properly insulate the attic.

Features of attic insulation

Proper thermal insulation of a house always requires compliance with a number of requirements:

• Warm air is always saturated with household steam. This means that heated air always contains traces of water. Wood exposed to high humidity tends to rot and mold. Therefore, it's worth considering creating a waterproofing layer;
• Insulation also requires waterproofing, as wood is breathable and allows air to pass through. Wood has a lower load-bearing capacity than brick or metal. Therefore, the insulation material should not create additional load on the floor. To prevent fires, the insulation must comply with fire safety requirements.

 

 

What materials are used for attic insulation?

Typically, only the ceiling is insulated. However, if the attic is planned for use as living space, the roof must also be insulated.

The following thermal insulation materials are used to insulate the attic:

• mineral wool and glass wool;
• polyurethane foam;
• expanded polystyrene.

Mineral wool and glass wool

Mineral wool and glass wool are environmentally friendly materials. These insulation materials are also fire-resistant and lightweight. Another advantage is their ease of installation.

The only drawback is excessive water absorption. This means that mineral wool and glass wool require additional waterproofing and a vapor barrier.

Polyurethane foam

It's a plastic material filled with gas. This material is sold in pressurized cans and is applied using a spray gun.

Its advantages include the absence of seams and, consequently, the absence of thermal bridges. Polyurethane foam has excellent adhesion to wood and requires no additional fastening systems.

This insulation is lightweight, so it doesn't place additional stress on the floor. Polyurethane foam also offers excellent thermal and sound insulation properties, as well as resistance to rot and aggressive environmental conditions. Its only drawback is its high price compared to similar products.

Expanded polystyrene

Expanded polystyrene is a type of foam plastic that has undergone additional processing. The material is highly durable. When used properly, it offers excellent vapor barrier properties. However, expanded polystyrene has a significant drawback: it promotes fire spread within a building.

Attic insulation techniques

If the attic is not used as a living space, the insulation process will look like this:

• To begin with, the surface to be insulated must be cleared of debris and mold;
• then you will need to treat the floor with an antiseptic and caulk any cracks, if any;
• Next, you will need to cover the attic with a waterproofing layer; it must be vapor-permeable to prevent the ceiling from rotting.
• then, spread out the joists to which the floor covering will be attached;
• Next, it is necessary to lay out the thermal insulation in an even layer, moving the gaps and cracks;
• then it will be necessary to lay waterproofing, but without absorbing steam;
• further, if the attic is planned to be converted into a living space, all layers will need to be filled with expanded clay and then tied;
• The final step is finishing.

Attic insulation is one of the most important aspects of home insulation. Therefore, it's important to pay due attention to the choice of materials and the quality of workmanship.