Is it possible to insulate the attic with foam

Often the attic space is converted into a living space. The structure under the roof requires insulation, since through it a considerable part of the heat escapes from the house to the street. You can insulate the attic with foam.

Advantages of Styrofoam

Thermal insulation foam is one of the quickest options for insulation. Positive material properties:

• convenient for installation, because easily cut, adjusted to the desired size, fixed on foam;
• affordable;
• economical: sheets for insulation of the attic will need 1.5-2 times less than mineral wool;
• safe, suitable for insulating a house inside without fear for the health of people;
• resistant to moisture;
• does not shrink over time;
• does not require laying a large layer with a high density and sheet thickness of 10 cm;
• suitable for overlapping cold bridges or rafters, where it is recommended to lay thermal insulation in 2 layers.

Polyfoam is a popular material for commercial purposes, as it is the fastest and easiest way to insulate. On installation, specialists make good money in a record short time. This is the best option for those who prefer to spend money rationally. The material almost does not absorb water, so it will not rot, mold, and lose its thermal insulation properties.

Attic insulation

The insulating material absorbs no more than 2% of the liquid, therefore it will not allow moisture to seep into the attic. The thermal insulation structure should consist of 5 main layers:

1. Roof and truss system.
2. Waterproofing.
3. Insulation.
4. Vapor barrier.
5. Decorative finishing.

Roof and truss system

The task of the foam is to prevent precipitation and winds from entering the roof. Especially if the roofing is slate or shingles, wooden or bar rafters.

Waterproofing

This layer is necessary so that moisture does not get in from the outside. Thermal insulation foam traps vapors and converts to thermal insulators.

As waterproofing, special membrane films or ordinary roofing material are used, which allows vapors to pass through.

If the walls of the attic are wooden partitions, a waterproofing layer for insulation is not laid, since there are no contacts with the environment.

Insulation

The task of the insulation is to prevent the attic from overheating from exposure to the rays of the sun in winter, to prevent temperature drops when cold air is supplied from the outside and warm from the room.

Foam plastic has low thermal conductivity, not exceeding 0.04 Vi / mk. In addition, it is recommended to insulate the attic with expanded polystyrene, mineral wool.

Vapor barrier

A layer of membrane and film protects the insulation from the penetration of vapors that provoke the accumulation of condensate and harm the thermal insulation material. If you do not equip the insulation with a vapor barrier, the roof will freeze due to the difference in air temperature inside the attic and high humidity outside.

Decorative finishing

For finishing the attic at the last stage, facing material, drywall, Knauf Therm foam is used. If the slabs are wooden, the wall insulation trim is attached directly to the rafters.On the floor, according to the lag system, the foam is laid on the roughing boards. Above - a vapor barrier film.

Polyfoam is a moisture-proof material. However, during installation, it is important to carefully seal the seams, filling them with special mixtures, the remains of expanded polystyrene or polyurethane foam.

Before installation, it is important to correctly calculate the required number of foam plates. It is better to take with a margin, especially if you need to cut shapes of a certain shape. The material must retain all its insulating properties. When buying, you need to make sure that it is solid, not exposed to atmospheric precipitation, not deformed.

Do-it-yourself attic insulation technology

Insulation of attic wall panels is an important stage for keeping warm in the attic. Especially if the roof does not reach the floor.

The insulation option depends on the shape of the roof. If it is flat, the foam is cut out according to the template, attached to the space between the crate. If it is complex or gable, fragments of foam are attached to self-tapping screws.

Stages of attic insulation:

1. Check the roof rafter system for strength, repair existing damage to the rafters or replace with new ones.
2. Overlap the waterproofing film by 10 cm over the entire roof area and over the rafter system. Secure with a construction stapler. If there are nails on the beams, they should be removed first.
3. Measure the distance between the rafters. Fill the spaces with pieces of styrofoam so that there are no gaps. Fix on polyurethane foam.
4. Seal tightly the joints between the rafters and the slabs.
5. Lay the boards on the foam in the form of a honeycomb system for additional fixation.
6. Lay a layer of vapor barrier - a special film similar to foam in properties. Attach and fix on top of the insulation.

At the last stage, you can clad the walls from the inside with plasterboard, plywood, OSB boards. Next, insulate the floors by laying a layer of foam plastic between the beams, waterproofing on top, vapor barrier.

How to make roof insulation with foam

For work you will need:

• frost-resistant glue or ordinary polyurethane foam;
• wooden slats for fastening;
• carnations, umbrellas;
• foam with a margin;
• vapor barrier film or membrane;
• construction stapler;
• scissors;
• a hammer.

Flat roof insulation:

1. Clean the roof from debris, dry thoroughly.
2. Install the first layer of waterproofing. Next - foam plates.
3. Tape all joints with tape.
4. Lay the insulation so that the slabs overlap the joints of the lower layer. Above - geotextile, sprinkled with gravel, crushed stone, expanded clay (thickness - 4-5 cm).
5. Perform a screed. Above - the topcoat of the roof.

For insulation from the inside, the surface of the ceiling is cleaned. The foam is laid with a glue fit for better adhesion. The voids at the joints are filled with a sealant. Plasterboard, suspended stretch ceilings are used as finishing.

If the roof of the attic is pitched, the installation steps are as follows:

1. Check all sections of the roof. Are there any leaks, damage.
2. Treat wooden elements with an antiseptic and fireproof impregnation. Metal fasteners and parts - anti-corrosion compounds.
3. Lay a layer of waterproofing on the lathing, secure with a stapler.
4. To glue the joints of the canvases with a special tape to increase the tightness.
5. Place the cut foam boards between the rafters. Fill the gaps with pieces. Fill the voids with sealant or polyurethane foam.
6. Install a vapor barrier film. Glue the joints with tape. Gaps between wooden rails and rafters - stapler, staples.
7. Sheathe the interior of the attic with finishing materials.

A waterproofing layer is not laid if it is already under the roof on the crate.In order to avoid the appearance of cold bridges and the formation of condensation, it is better to fill the gaps and voids between the foam sheets with a sealant, polyurethane foam. If the covering is made of metal sheets or metal tiles, in addition to it, a sound-insulating layer should be laid on top of the foam plastic to increase the soundproofing properties.

Insulation of the attic with extruded polystyrene foam

Expanded polystyrene is also used to insulate the attic. It is laid on top of the rafters so that no gaps appear. If the slabs at the roof overlap are in the form of steps or “spike in groove”, the sheets of expanded polystyrene are laid in the space between them, fixed on the corners, brackets. A flat surface should be obtained, a gap should remain between the layer of thermal insulation material and the waterproofing for ventilation of the roofing cake.

Step-by-step actions:

1. Cut the sheets of foam, taking into account the width of the step of the rafters. Cut off excess with a sharp knife if necessary.
2. Overlap the canvases by 150 mm.
3. Glue with special tape. Fix with a stapler to the rafters.
4. Install a second layer of extruded polystyrene foam if the thickness of the sheets is less than the rafter legs. Above is a layer of vapor barrier, then a crate or frame for sheathing the attic.

At the final stage, final finishing is carried out.

When heated to 40 degrees, polyfoam emits unpleasant odors, volatile products with a styrene content of 3 hazard class. Even if the material cools down, the unpleasant odor remains poisonous and does not fade away. Another significant disadvantage of polystyrene is the low refractoriness of the G2, G3 class. However, manufacturers began to add a fire retardant that extinguishes a fire source in a matter of seconds.