Should You Insulate Between Roof Rafters

On new build or replacement pitched roofs the ideal build up would be insulation fitted over and then between the rafters giving a big boost for airtightness image credit.

Should you insulate between roof rafters.

For rolled insulation location it in between roof covering rafters. Make sure it is flush against the wood as also a 1 inch gap can create a 20 percent heating loss. Hire a pro to install spray foam insulation. You can use rigid foam panels or do as tom silva does with nearly all houses these days.

If you re considering turning your attic into conditioned storage or living space it s worth changing tactics to insulate between the rafters and wall joists instead of the floor. Insulating the rafter space will give you a warm loft. You can add insulation to the floor. Usually you will certainly fill the insulation blower with the insulation and blow it between the attic floor joists.

A vent baffle should be installed between the insulation and the roof decking to maintain the ventilation channel. The ones i ve used are made of styrofoam and iirc they cost around 2. If your attic is going to be converted into livable space then you will need to insulate the roof rafters. The rafters are joined together by a horizontal ridge board at the top and tied together by ceiling joists at the bottom.

The current trend is for a warm roof where insulation is installed between the rafters thereby keeping the roof timbers warm. The will hold open an air gap of approximately 1 inch to allow airflow past a layer of insulation. Install ventilation baffles into the space between the rafters before you install the insulation usually by stapling into place. This means insulating between or below the sloping beams that form the construction and support a sloping roof.

You can buy air ducts that staple to the inside of your roof above the eave vents and fit between the rafters. Consider using high density r 30 batts which are as thick as r 25 batts but fit into 2x10 framing. Attic moisture problems are often the result of heated air from the living space rising up into the attic which is not heated.