Insulating Sloped Roofs

Eric dymond lives in a 1920s baltimore row house that needs a new roof.

Insulating sloped roofs.

A layer of spray polyurethane foam can be installed against the underside of the roof sheathing with the rest of the rafter cavity filled with air permeable insulation. Sloped roof insulation providing high quality insulation between cathedral ceiling roof joists is an easy method of improving the overall energy performance of a building. Staple plastic or foam baffles to the roof sheathing near the eaves to keep the material away. For the past 10 years energy code cycles have focused on wall assemblies.

Dual purpose structural deck and insulating planks are comprised of. For the same reason insulation shouldn t touch the roof s underside. Wood framed sloped roofs have been a common means to provide shelter and protection from the weather for centuries but high performance building enclosures often focus on wall designs rather than roof designs. Roof insulation refers to the practice of installing insulation on the roof slope both above and below the rafters.

Rockwool comfortbatt is a stone wool insulation that provides reliable thermal resistance over time. If you want to vent a low slope roof here s what you need to do. 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. Dual purpose structural deck and insulating planks.

Types of low slope roof thermal insulation rigid board insulation. Currently the built up asphalt roof is installed over homasote or something similar and a roof deck made of wood planks. He plans on replacing the low slope built up roof with an epdm membrane and the question is how to insulate it correctly. The airflow from the soffits to the ridge vent keeps the roof cool and prevents ice dams and the material will block that flow.

Specify roof trusses or conventional framing deep enough for 12 in. Provide soffit fascia or wall mounted vents at the perimeter of the shallow attic that will allow exterior. Of insulation plus room for an air gap of. Insulating a sloping roof.

There are lots of ways to insulate a low slope roof and most of them are wrong. It s worth insulating the sloping insides of a pitched roof in order to conserve heat if the space is to be used for anything except simple storage.