Del-Val 403 Trowel-Grade Foundation Mastic

Product Fast Facts
Heavy-Bodied Consistency
Meets ASTM D4586, Type I


Del-Val 403 Trowel-Grade Foundation Mastic is a trowel-applied, heavy-bodied, fibered asphalt compound for exterior, below-grade masonry wall surface applications. Del-Val 403 Trowel-Grade Foundation Mastic is recommended to protect porous or irregular surfaces. Use in conjunction with Del-Val 401 Fibered Foundation Coating to secure a tight seal against moisture. When dry, Del-Val 403 is very flexible and protects very well against certain natural chemicals found in soil.


Del-Val 403 Trowel-Grade Foundation Mastic is specially formulated to reduce dampness and moisture infiltration through foundation walls, parapets and firewalls.


All surfaces must be clean and free of any oil, grease, dirt and all other foreign matter. Must stir coating before using.


Apply with a contractor’s trowel. Make sure that the area that is going to be covered is done so in an evenly consistent application. Please allow the mastic at least 36 hours before backfilling to allow the mastic time for curing.


Apply at the rate of 5-6 gallons per 100 square feet.

Cleanup Del-Val 403 Trowel-Grade Foundation Mastic

Clean tools with Del-Val Orange Cleaner & Degreaser or mineral spirits, taking necessary precautions when handling combustible liquids.


DO NOT THIN. DO NOT HEAT CONTAINER. DO NOT store in an area where temperatures exceed 120˚F

Code Approvals/Compliance

Meets ASTM D-4586 Type I. (Asbestos Free Cement)

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