boshen Waterproof Membrane for Shower 3.77ft x 29ft 108sq ft Underlayment Shower Membrane 20mils Thickness Waterproofing Polyethylene Fabric for Tiles, Shower Walls, Bathroom Floors is up for auction in Tools & Home Improvement. The current bid is $18.00, 63% below the $48.99 MSRP, in New/Like New condition. This auction has ended — similar items appear in live auctions regularly.