For Filling Cracks, Holes And Minor Imperfections In Subfloors To Form A Smooth Even Surface. Used To Patch Floors, Walls And Other Surfaces In Preparation For A Decorative Finish. Bonds To Drywall, Wood, Concrete And Masonry. Non-Shrinking Patch Sets In 20-30 Minutes. Can Also Be Used To Patch Drywall And Plaster. Four Pounds With 20 Ounces Of Water Covers 5 To 14 Sq. Ft. Twenty-Five Pounds With 4 Quarts Of Water Covers 30 To 80 Sq. Ft. Coverage Depends On The Thickness Of Application.