OverviewRoofBlock Buckets 020722 01

RoofBlock Primer WB is a water-based, rubber-based, low-tack primer which is specifically formulated to provide excellent adhesion.

Prime as needed all structural concrete, masonry, wood, fiber reinforced exterior sheathing or exterior gypsum board surfaces on which RoofBlock HT will be applied.

Designed to be used in ambient temperatures and surface temperatures of 40°F (5°C) and rising.



Installation Application

RoofBlock Primer WB may be applied with roller or brush. Apply RoofBlock Primer WB to a clean, dry, dust free, and frost free surface at a coverage rate of approximately 350 to 400 square feet per gallon on concrete.

Exterior gypsum sheathing board products will vary in texture, performance and porosity. The coverage rate for RoofBlock Primer WB will vary due to substrate texture and porosity. Specific testing for coverage is recommended.

The primer should be spread sufficiently to avoid areas of excess material. Areas of excess material will lengthen the curing time on the application of the RoofBlock Primer WB.


Limit the application of primer to what can be covered with RoofBlock HT in one working day. Any areas not covered with membrane during the day must be recoated. Be sure to cover all open containers when not applying primer.