Insulating Dormer Attic Space

For diy attic insulation you ve got two choices.

Insulating dormer attic space. Staple the dormer s ceiling insulation s flaps to the roof trusses with the insulation s paper backing facing down. Spray foam insulation is capable of reaching places in the dormer roof that other methods of insulation cannot. Once you ve decided which type is best for you examine the material options and prices to home in on the right product. You can mix the type and material of insulation too.

If the attic will ever be heated or used as living space insulate with batts blanket or wet blown between roof rafters and on end walls. Dormer roofs are roofs that contain rooms and can present considerable challenges when it. Loose fill or batt the common term for blanket insulation. Out of all the above mentioned common methods of insulating dormer roofs the most dependable and preferred is spray foam insulation for the following reasons.

1a attic access door. You need to leave a small air gap of about 25mm behind the insulation and it is worthwhile carrying the rafter insulation up into the attic space even if it is a reduced thickness above the ceiling. It is the classic design with knee walls in the upstairs rooms and storage access in the side attics. A second ply of batt insulation should be unfaced and laid perpendicular to the first ply.

Cut the ceiling s batt insulation to size with the knife. Having the attic space insulated means it acts as a buffer to reduce the temperature difference that the ceiling insulation has to deal with. Loose fill can be blown under the floor between ceiling joists. I can t seem to find consistent and clear info on what i need to do with insulating the side attics in my 1940s cape.

Access under the flooring is also an issue requring the. Measure the dormer s ceilings for insulation with the tape measure if needed. Heated used as living space. Make sure your home is properly insulated in all these locations.

Why spray foam does it better. If the air distribution is in the attic space then consider insulating the rafters to move the distribution into the conditioned space. Because of this i am inclined to insulate under the roof slope as opposed to the knee walls and side attic flooring. Do dormer bungalows and houses with attics in the roof space need a different approach to insulation.

Do not insulate the dormer s ceiling when it connects to an uninsulated attic space. Both can be added to uninsulated attics or layered over existing material. The ideal attic insulation r value is different than the ideal wall insulation r value.