The following procedures apply to wood roofs sheathed with exterior plywood or oriented strand board (OSB). Board sheathing is not an acceptable base for acrylic and must be covered with plywood or OSB. Since joints and defects may show through the acrylic, choose a plywood with one filled face and apply it neatly if the roof is to serve as a deck or will be very visible. Keep gaps between sheets less than 1/4", but observe minimum gaps specified by the sheathing manufacturer. If the weather is hot, priming is essential.
STEP 1: Fasten both new or existing sheathing with
screws, ring-shank nails, or other pop-resistant fasteners.
STEP 2: Patch large defects with a wood filler.
STEP 3: Belt sand any patches, as well
as splintering wood and offset seams.
STEP 4: Vacuum well to remove all dust.
STEP 5: Caulk all sheathing joints and tool the caulk flat.
STEP 6: Caulk all transitions and tool a cove in the caulk.
STEP 7: Prime the sheathing with a thin coat of
Conservation Technology Acrylic ST.