G‑Floor Seam Tape is 4” wide, single-sided, waterproof adhesive tape, applied on the underside of the flooring. Seam tape is commonly used two parking pads are installed side by side. This allows the entire mat to ‘float’ from contraction and expansion due to temperature changes. We do not recommend using seam tape if piecing three or more parking pads together, as it will cause the middle mat to ripple. See info on our Seam Tape at: https://bltllc.com/gfloor-universal-flooring/accessories/