Insulate Attic Roof Rafters

Install ventilation baffles into the space between the rafters before you install the insulation usually by stapling into place.

Insulate attic roof rafters.

If the plastic sheeting is in pieces overlap the pieces by 8 inches and staple it in place directly to the roof rafters and the wall. This construction approach was first used in the 1970s and it has been implemented much more widely since it was first included in the international code council s icc model building code in 2007 irc section 806 4. You can use rigid foam panels or do as tom silva does with nearly all houses these days. 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.

If you re not do the attic floor. 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. Place the plastic sheeting on top of the rolled insulation. Do not use plastic sheeting in this case.

If there is a floor you will need to remove it to properly insulate the roof rafters. That s because it s easier for the contractor to spray than clean up existing insulation deal with any can lights or venting etc. If you re using the attic for living space then you need to insulate the rafters. Usually you will certainly fill the insulation blower with the insulation and blow it between the attic floor joists.

Although the paper or foil backing of the insulation is a vapor barrier the added visquine covers completely with no breaks making sure no moisture forms in the cavity. Once the insulation is in place between all the rafters staple up a vapor barrier of 6 ml. For rolled insulation location it in between roof covering rafters. Hire a pro to install spray foam insulation.

If your attic is often used or perhaps you plan to convert it in the future you will need to insulate the inner surfaces of the roof. For a correct approach an inner roof lining is required. Attic moisture problems are often the result of heated air from the living space rising up into the attic which is not heated. The technically correct approach depends on a number of factors.

Most unvented attics incorporate spray polyurethane foam spf on the underside of the roof deck and attic walls. Whether or not there is an inner roof lining and the total thickness of the roof structure. Make sure it is flush against the wood as also a 1 inch gap can create a 20 percent heating loss.