Schlüter-TROBA  Surface drainage sheet

Terraces and paths are traditionally installed by placing pavers loosely in beds of gravel, crushed stone or mortar. To ensure durable assemblies, these installations must include drainage and protection for the waterproofing layers beneath.

Schlüter-TROBA guarantees this durability. The pressure-stable studded polyethylene sheet has been successfully used as an effective surface drainage for over 25 years. It forms a hollow chamber between the waterproofing assembly and the gravel or crushed stone layer. These chambers prevent mechanical stresses on the waterproofing layers beneath, while serving as drainage channels that dependably channel away any penetrating seepage.

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Product image TROBA 1©Schlüter-Systems KG
Cross-section drawing TROBA 1©Schlüter-Systems KG
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Product image TROBA 1
Cross-section drawing TROBA 1

General product information

What this product does

Schlüter-TROBA is a reliable and permanently effective drainage system for use over sloped waterproofing layers. It consists of a perforated, pressure-stabilised studded polyethylene sheet and forms hollow chambers between the waterproofing assembly and the gravel or crushed stone layer.

Any seeping water penetrating the covering assembly passes through the lateral perforations of the trapezoid studs to the sloped waterproofing layer, where it runs off to the drainage exit under normal gravitational force through the drainage cavities. Schlüter-TROBA has been tried and tested as a surface drainage system for over 25 years.

How to install this product

  1. The load bearing substrate and the waterproofing layer placed on it according to DIN 18531 must have an adequate slope for drainage and be connected to the designated drainage exit.
  2. TROBA is placed loosely over the waterproofing assembly independent of the slope. Adjacent lengths are placed and overlapped along the flat edges, while the ends of two courses are overlapped by at least one row of dimples.
  3. The surface assembly is installed directly over the placed TROBA according to current industry standards.
  4. Note: We recommend the profiles from our product range for edging profiles, movement joints and floor-wall transitions.

What this product is made from

Schlüter-TROBA consists of a pressure-stable polyethylene sheet with a structure of trapezoid-shaped, 8 mm deep, studs. To allow penetration of seepage water, the outer corners of the studs feature small holes. The contact area of the matting is approx 50%; vault-like drainage spaces constitute the remaining 50%. The material is non-rotting and dimensionally stable in a temperature range from - 40°C to + 80°C.

Material properties and areas of application

Schlüter-TROBA is primarily installed in horizontal applications, over sloped waterproofing layers, according to DIN 18531. It provides an effective drainage layer between the waterproofing layer and the surface assembly above. Its main areas of application are balconies and terraces, which have been waterproofed.

The loosely placed TROBA is adequately stable against mechanical stress during the installation process, e.g. it may be walked on or driven over with wheelbarrows used for the transport of required material.

The cover construction, consisting of self-supporting pavers or stone slabs, can be installed over gravel or crushed stone. TROBA prevents the stones from sinking into the bitumen waterproofing.

Water which penetrates the mortar bed is guided, under normal gravitational force, through the drainage cavities of TROBA toward the drainage exit.

How to look after this product

Natural shifts may occur in paver coverings over loosely installed crushed stone/gravel due to one-sided or corner loads.