Fiberglass Insulation Roof Rafters

Use your straightedge to compress the insulation before cutting and use a very sharp utility knife to assure a good straight cut across the fiberglass batt.

Fiberglass insulation roof rafters.

The friction of the fiberglass insulation material against the rafters baffles and plywood or wood slats is. 7 staple sheets of 6 mil plastic over unfaced insulation to create a vapor barrier. Unfaced batting insulation depends on a friction fit to keep it place. The rafters in cathedral ceilings are usually made of 2x10 ft.

Vented attics have insulation installed underneath the roof deck in direct contact with the decking. Air sealing hot roofs is critical. Fiberglass insulation can compress and lose r value and it s also unable to stop air from leaking out of or into your house. Hot roofs are insulated above the rafters.

Because the insulation is so close to the roof and you want to avoid unwanted moisture buildup these roofs will need to be completely sealed off. Unfaced insulation has no tabs and stays in place with friction between the fiberglass and the rafters. And owens corning ecotouch high density insulation products are designed specifically for these rafters.