Use where concrete meets concrete to prevent cracking on sidewalks, driveways, patios, retaining walls, etc. Also, an excellent sill plate and top plate sealer. Manufactured with cane fibers and saturated with asphalt, it is insect, decay and weather-resistant with low water absorption properties and no damage from freeze/thaw cycles. Compresses to 50% of its thickness and expands to 70% of its thickness. Bonds well to poured concrete, won't work loose during expansion and contraction. Easily cut and trimmed to any size or shape with standard tools. 1/2" T. x 4" W. x 5' L.; 40-pieces per carton.