General InformationGreen Roofs
Rainwater Harvesting
Ponds and Wetlands
Energy-Efficient Building
Waterproofing
EPDM Roofing
Acrylic Roofing
Preparation
Asphalt Roofs
Metal Roofs
Wood Roofs
Concrete Roofs
Insulated Roofs
Basic Procedure
Inside Corners
Outside Corners
Skylights
Posts
Pipes and Drains
Documents
ARYLIC ROOFING: PREPARING AN INSULATED ROOF
The following procedure offers an effective way to waterproof and insulate existing low-slope roofs. It is ideal for older, poorly-insulated structures because there is no interior mess and no risk of roof condensation. If the insulation is to be coated with acrylic, use extruded polystyrene insulation with 40 psi compressive strength. For a more abuse-resistant surface, or where the roof is to serve as a walkable deck, apply plywood or OSB sheathing over the foam. If the existing waterproofing is to be left in place, the plastic air/vapor barrier film can be omitted.
STEP 1: Broom the surface clean
and remove any sharp protrusions.
STEP 2: Apply a high-quality air/vapor barrier
film, such as Tenoarm, over the surface.
STEP 3: Attach decay-treated boards around the edge.
The boards must be as thick as the insulation that follows.
STEP 4: Screw foam insulation boards using at least
six insulation washers per 2 ft x 8 ft sheet.
STEP 5: Caulk small gaps in the foam boards with
water-base acrylic caulk and toolthe joints flat.
STEP 6: Spray foam larger joints in the foam boards and cut
off the excess with a knife after the foam has fully hardened.
STEP 7: Prime the foam boards with a
thin coat of Conservation Technology Acrylic ST.