Foam Board Insulation Attic Rafters

By adding the insulation under the rafters to maintain a ventilated roof at a cost of say1600 for a r28 airsealed radiant barrier product with the ability to add more if needed at a later date how is that a bad idea if an air sealed attic floor w blown in will cost roughly the same and i still won t have a good environment for hvac etc.

Foam board insulation attic rafters. R 7 5 scored squared edge rigid foam board insulation sheathing model 88wd view the owens corning exterior insulation 17 74 17 74. A brief snippet of how and why i used rigid foam insulation for some areas of the tiny house. Often the r value of fiberglass insulation is too low and requires the rafters to be retrofitted making foam board a better choice. 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.

Better than spray foam thermal break and relatively consistent r 30. Here s how to use 3 layers of 2 inch polyiso foam board to meet code and keep your ne. Owens corning foamular 150 1 1 2 in. The superattic system utilizes proprietary silverglo rigid foam insulation panels to fully seal and insulate the attic directly beneath the roof rafters and directly inside the gable ends.

You can use rigid foam panels or do as. 2 snap a chalk line between the length measurements. Unlike solid insulation products that require careful measurement cutting and fitting spray foam can cover even the most uneven surface instantly. Affix rigid foam insulation to the attic side of the hatch or door.

Some types of thicker foam board insulation are available but they may need to be special ordered. Measure the length and width between two rafters in your attic and transfer the measurements to a 4 ft by 8 ft of rigid foam insulation board. Pull down stair or ladder. When building my current home i was faced with a dilemma on how to insulate a bonus room that would be upstairs.

The superattic system creates a continuous air and insulation barrier directly beneath the attic roof with no thermal bridging to compromise energy. Add weatherstripping around the perimeter and a sweep to the door of a walk up attic. Attic 7 basement 12 ceiling insulation 8 crawlspace 6 exterior sheathing 13 exterior wall foundation 17 exterior wall 4 floor 2 garage 9. Attic hatch or door.