Peel and Stick Membrane Sheets (25 sheets per box). nVent NUHEAT Membrane is a tile underlayment that can be installed over the entire subfloor for uncoupling, crack isolation, and to make the installation of nVent NUHEAT Cable quicker and easier. NVent NUHEAT Membrane is comprised of a polypropylene layer, with square-shaped pillars, that is heat-welded to a layer of non-woven polypropylene fabric. The fabric absorbs thinset in order to bond the Membrane to the substrate below. The square-shaped pillars provide vapor management, allowing moisture to escape from the substrate during the curing process. nVent NUHEAT Membrane offers waterproofing when installed with waterproofing seam tape.