FloorPro, 40 LB, #565, Self Leveling Underlayment, Specially Formulated, Portland Cement Based, Self Leveling Underlayment Used To Smooth & Flatten Interior Surfaces Prior To The Installation Of Floor Covering, Due To Its Unique Leveling & Drying Characteristics It Allows Floor Covering Installation To Proceed In As Little As 6 Hours, Coverage 43 SQFT Per 40 LB Bag At 1/8" Thickness, Install From Featheredge Up To 5" Thick.