Black Jack 3.6 qt Fibered Roof Coating penetrates, resaturates, and protects dried-out and exposed roofing felt. It can also be used on metal roofs, siding, exterior foundation walls, and all other concrete and masonry surfaces. The coating is easy to apply, does not run or sag, and is intended for exterior use only—do not use on shingle roofs. Ensure the roof is clean and dry before application. It covers approximately 35 sq ft per gallon, and cleanup requires mineral spirits. Allow 48 hours before backfilling