Barrier-Bac XF Seam Tape is a ribbed 30 mil thick tape offering a very high adhesive strength to seal all seams. The tough outer layer is a 5 mil multi-ply, texture, cross laminated membrane can have long life expectancy underground. The adhesive coating is a 25 mil proprietary modified asphalt offers super adhesive strength in low temperature. All seams and/or joints can be joined by seam tape. All penetrations must be sealed with a Barrier-Bac vapor retarder and seam tape. This ribbed Barrier-Bac XF Seam Tape works perfectly with ribbed Barrier-Bac Vapor Barrier products to form an interlock mechanical bond and tightly block moisture migration from entering through seams. Seam Tape is available in standard roll size of 4" × 150 ft. nine rolls in one carton. 180 rolls on a pallet.