Duradek has tweaked its Ultra roofing membrane to create a waterproofing product specifically for use beneath exterior tile installations. Unlike the roofing membrane, Ultra Tiledek has fabric embedded in its surface to promote adhesion with thinset mortar.

The company says the 60-mil PVC membrane is completely compatible with thinset adhesive, can be used in high-traffic areas, is stable in high-heat, high-moisture conditions, and won’t degrade. It meets code requirements for use over living spaces, and has passed ANSI and ASTM tests required by the Tile Council of North America and the Terrazzo Tile and Marble Association of Canada.

One hitch is that you can’t buy and install the membrane yourself. Ultra Tiledek can be installed only by trained contractors specializing in roof-deck and balcony waterproofing.

The company didn’t provide pricing.

Duradek, 800/338-3568, duradek.com/tiledek.