Insolating The Attic Directly On The Roof Joints

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.

Insolating the attic directly on the roof joints.

The technically correct approach depends on a number of factors. When hvac equipment is in the attic insulation and an air barrier at the roof line brings that equipment within the conditioned enclosure envelope thereby allowing it to operate in more favorable temperature and humidity conditions without air leakage and heat loss gain directly to the exterior. An unfinished attic is an attic that is not considered part of the living space. Do not use plastic sheeting in this case.

They are the easiest to insulate because the insulation is installed between the framing members or joints of the floor according to the university of tennessee extension. Essentially this system offers excellent insulation value because wood conducts heat and cold. Insulating an unfinished attic can be a simple diy project. Whether or not there is an inner roof lining and the total thickness of the roof structure.

If you re insulating the roof directly to insulate the roof itself you either use spray foam or retrofit with it with rigid foam board. Insulating the pitched roof 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. With one inch extruded polystyrene foam board insulation between the drywall and the roof members the r value increases to r 25 with no thermal bridges.