Schluter-TROBA-PLUS is a safe and durable surface drainage system for use on sloping surfaces (waterproofing, slabs on grade, etc.). This drainage system is made up of a polyethylene mat with a permeable non-woven fabric. In the case of TROBA PLUS 8G, the mesh size of the fleece is approximately 2 x 2 mm. The space between the fleece-covered studs, on which the flooring rests, allows for drainage with a very high water discharge capacity. Schluter-TROBA-PLUS protects the waterproofing when laid over it. The bosses, arranged in a dense network, are shaped like truncated cones and can withstand high pressure loads ranging from 300 kN/m² (30 t/m²) to 390 kN/m² (39 t/m²). The air gap between the embossed mat and the nonwoven material provides thermal and acoustic insulation and protects the substrate from thermal stress. The result is an even load distribution over the entire surface of the substrate. Schluter-TROBA-PLUS 8 and 8G raise the surface by 8 mm, Schluter-TROBA-PLUS 12 by 12 mm. Minor differences in level, such as irregularities (or bumps in the overlap area of the waterproofing) that can lead to water retention, are effectively covered by TROBA-PLUS. However, obvious defects must be removed before Schluter-TROBA-PLUS is installed, using levelling mortar.