How To Insulate A Flat Roof Attic

A layer of rigid insulation board can be added either on top of the roof s weatherproof layer or directly on top of the timber roof surface with a new weatherproof layer on top of the insulation.

How to insulate a flat roof attic. Sealing bypasses bypasses are anywhere that there is a break in the insulation. Use rigid foam insulation panels on your flat roof before applying the final roof covering or inside the house before adding sheetrock or paneling. However if you have a cathedral style garage roof you will need a scaffolding to get into the upper areas of the roof. With flat roof insulation a vapor barrier should sit between the joists and ceiling panels and the insulation on top.

A flat roof should preferably be insulated from above. With a warm roof the usual process is to split the insulation into two layers. With this method only the attic floor is insulated. It should be installed on tapered 2x furring strips in order to slope the surface of the roof to drains.

If you have a flat garage roof and an attic above you can install the garage insulation from below using a standard ladder. In either case you will need to follow the general steps below to insulate your garage roof. Framing this out and buying 30 r fiberglass insulation will cost you about 50 more than just buying 5 inches of polyiso equivalent of 30 r. The simplest and cheapest solution for attic insulation is the so called cold attic.

See below for a shopping list and tools. This old house general contractor tom silva and host kevin o connor demonstrate the proper way to insulate an attic. Rigid foam panels are available in thickness. The materials used to insulate under the roof include batts of mineral or glass wool insulation held in place by battens of wood attached to and across the rafters.

This is best done when the roof covering needs replacing anyway.