Should You Insulate Between Roof Rafters

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.

Should you insulate between roof rafters.

A vent baffle should be installed between the insulation and the roof decking to maintain the ventilation channel. You can add insulation to the floor. Consider using high density r 30 batts which are as thick as r 25 batts but fit into 2x10 framing. Make sure it is flush against the wood as also a 1 inch gap can create a 20 percent heating loss.

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. For rolled insulation location it in between roof covering rafters. Insulating between rafters will do no good because the attic should be ventilated and the rafter insulation would be between two unheated spaces.

You can use rigid foam panels or do as tom silva does with nearly all houses these days. The rafters are joined together by a horizontal ridge board at the top and tied together by ceiling joists at the bottom. Attic moisture problems are often the result of heated air from the living space rising up into the attic which is not heated. If your attic is going to be converted into livable space then you will need to insulate the roof rafters.

This means insulating between or below the sloping beams that form the construction and support a sloping roof. Insulating the rafter space will give you a warm loft. 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. Install ventilation baffles into the space between the rafters before you install the insulation usually by stapling into place.

Hire a pro to install spray foam insulation. The will hold open an air gap of approximately 1 inch to allow airflow past a layer of insulation. You can buy air ducts that staple to the inside of your roof above the eave vents and fit between the rafters.