Roof Rafter Insulation Materials

Roof insulation configurations for unvented rafter truss assemblies.

Roof rafter insulation materials.

Fiber material is pre fabricated into a blanket roll that is pressed between two sheets of paper or foil or just one side may be shielded as is the case with rolls. Rolls are easy to transport and can be cut to the length you need. Commonly used and inexpensive but fibers can irritate lungs and skin though less so than in years past thanks to better manufacturing and it s less effective at blocking airflow than other materials. Images courtesy simpson gumpertz heger.

Fiberglass is easily the most popular material but mineral wool is fairly common as well. Owens corning raft r mate 22 1 2 in. In heavy duty construction a ridge beam might be used instead. These specialty vents do not affect the.

We prefer recycled insulation for obvious reasons. Normally people use mineral wool or insulation boards to insulate the rafter space. Unlike solid insulation products that require careful measurement cutting and fitting spray foam can cover even the most uneven surface instantly. If you are planning to use wool then it is imperative you wear protective clothing goggles and a face mask since the wool is an irritant.

Rafter vents or insulation baffles install in any rafter space to create narrow gaps that direct fresh air from the soffit vents to the peak of the roof. Polyurethane or polystyrene spray foams can provide thorough coverage to roof rafters and attic walls in much less time than is needed for other materials. In finished space insulation is placed between the rafter boards and drywall or other material is fastened to the face of the boards. You can either install faced batting insulation which has a paper or plastic vapor barrier already attached or add a vapor barrier after installing unfaced insulation.

Ibc dictates acceptable placement and composition of roofing materials in chapter 15 but describes required thermal efficiency of the roof in chapter 13 which references the international energy conservation code iecc the minimum required thermal resistance varies. Batts come in pre cut lengths which makes installation fast and easy especially for framed spaces. Rolls batts or blown in insulation. 1 attach baffles to the.

The ridge board must be the same width as the rafter boards. Rafter boards are fastened to the ridge board at the peak and the top plate where they join the wall. These insulation panels also provide excellent noise control. Use these to cover large areas.