Should You Insulate Between Roof Rafters

This means insulating between or below the sloping beams that form the construction and support a sloping roof.

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. The current trend is for a warm roof where insulation is installed between the rafters thereby keeping the roof timbers warm. Insulating between rafters will do no good because the attic should be ventilated and the rafter insulation would be between two unheated spaces. The will hold open an air gap of approximately 1 inch to allow airflow past a layer of insulation.

Insulating the rafter space will give you a warm loft. 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. You can use rigid foam panels or do as tom silva does with nearly all houses these days. You can also add rigid foam insulation under the rafters which adds r value and eliminates thermal bridging through wood rafters.

The ones i ve used are made of styrofoam and iirc they cost around 2. The rafters are joined together by a horizontal ridge board at the top and tied together by ceiling joists at the bottom. A vent baffle should be installed between the insulation and the roof decking to maintain the ventilation channel. For rolled insulation location it in between roof covering rafters.

Consider using high density r 30 batts which are as thick as r 25 batts but fit into 2x10 framing. In order to avoid damage to the roof deck you should insulate ceilings to create an air barrier between the living space and an unfinished attic or airspace underneath the roof deck. Usually you will certainly fill the insulation blower with the insulation and blow it between the attic floor joists. Attic moisture problems are often the result of heated air from the living space rising up into the attic which is not heated.

Hire a pro to install spray foam insulation. If your attic is going to be converted into livable space then you will need to insulate the roof rafters. Install ventilation baffles into the space between the rafters before you install the insulation usually by stapling into place.