Insulating Low Pitch Attic

Rigid board insulation is the most common type of insulation used in low slope commercial roofing.

Insulating low pitch attic. Insulate the walls carefully and effectively so that you don t wind up with further problems down the road. Currently the built up asphalt roof is installed over homasote or something similar and a roof deck made of wood planks. In older buildings the usual method is to install fiberglass batts or cellulose on top of the leaky ceiling with a gap of a few inches or sometimes a few feet between the top of the insulation and the roof sheathing. Gaps in the framing need to be sealed any holes from electrical wiring must be filled and so on.

Plan to pull up the flooring and layer new insulation on top of the old. Insulfoam sp is specifically designed for low sloped roof applications that employ mechanically fastened or ballasted tpo pvc and epdm as well as low sloped built up modified bitumen and fully adhered single ply roofs that incorporate cover boards or slip sheets. To create a warm pitched roof insulation such as kingspan kooltherm k7 pitched roof board should be fitted between and over the rafters. He plans on replacing the low slope built up roof with an epdm membrane and the question is how to insulate it correctly.

There are lots of ways to insulate a low slope roof and most of them are wrong. But if the floor is covered in plywood you can t stuff enough insulation beneath it to do the job sufficiently not even in warm climates. In warm climates zones 1 through 4 low density open cell spray foam insulation is the typical choice since it is vapor permeable and will allow drying of the exterior sheathing and roof framing if they happen to get wet via diffusion into the interior of the building. Although some builders insulate a low slope roof with the same techniques used for a house with a big attic they should be using a different approach.

Because the simplest and cheapest way to insulate an attic is to add material to the floor. You want to keep condensation from forming anywhere in your attic. It is made from cellular plastic or fibrous materials and pressed into boards. If the roof is vented the ceiling must be air sealed to prevent moisture laden air from reaching the attic.