Fiberglass Insulation Roof Rafters

7 staple sheets of 6 mil plastic over unfaced insulation to create a vapor barrier.

Fiberglass insulation roof rafters.

Although many builders have installed fiberglass batt insulation between attic rafters to insulate cathedral ceilings and attic roofs this technique isn t as effective as more modern methods of roof insulation. And owens corning ecotouch high density insulation products are designed specifically for these rafters. Unfaced insulation has no tabs and stays in place with friction between the fiberglass and the rafters. Hot roofs are insulated above the rafters.

Attach insulation staple it to the rafters or scabbed on boards with a staple gun so that the paper backing is toward the interior of the room to act as a vapor barrier. R 30c and r 38c are available in both kraft faced and unfaced. The friction of the fiberglass insulation material against the rafters baffles and plywood or wood slats is. 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 can compress and lose r value and it s also unable to stop air from leaking out of or into your house. Vented attics have insulation installed underneath the roof deck in direct contact with the decking. The rafters in cathedral ceilings are usually made of 2x10 ft.