Schlüter®-TROBA | Schlüter-Systems


Application and Function

Schlüter-TROBA is a reliable and permanently effective drainage system for use over sloped waterproofing layers. It consists of a perforated, pressure-stabilized studded polyethylene sheet and forms hollow chambers between the waterproofing assembly and the gravel or crushed stone layer. Any water penetrating the tile covering and the screed passes through the perforations to the waterproofing layer, where it runs off freely through the drainage cavities. Schlüter-TROBA has been tried and tested as a surface drainage system for over 25 years.



  1. The load-bearing substrate and the waterproofing membrane placed on it, in compliance with DIN 18531 must be adequately sloped toward and connected to the designated drainage exit.
  2. Irrespective of the direction of slope, TROBA shall be loosely laid over the waterproofing membrane. 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. Please note: With respect to edging pro- files, flexible joints, and floor/wall transitions, please refer to the appropriate profiles from our product range.



Schlüter-TROBA consists of a pressurestable polyethylene sheet with a structure of trapeziod-shaped, 8 mm deep, studs. To allow penetration of seepage water, the outer corners of the studs are equipped with holes. The contact area of the matting is approximately 50 %; vault-like drainage spaces constitute the remaining 50 %. The material will not rot and is form-stable within a temperature range of -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 selfsupporting 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.




Bundle = 20 Units



Schlüter®-TROBA-ZFK are tile spacers to ensure a uniform joint appearance for the loose installation of ceramic tile elements, natural stone or concrete pavers in gravel or crushed stone beds, e.g. over Schlüter®-TROBA. The joint width is 3 mm, the height of the spacers is 15 mm. A height of 30 mm can be achieved by snapping the tile spacers together.


Package = 50 pcs.



Frequently asked questions

Area load

Which area loads are recommended for Schlüter®-TROBA? Can the assembly withstand the weight of a vehicle?

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Since assemblies with Schlüter®-TROBA involve beds of gravel or crushed stone, which are in direct contact with the substrate between the individual stilting points, Schlüter®-TROBA does not limit the area load per se. 

Rather, the maximum load is determined by the covering assembly. All variants of our area drainages are sufficiently stable to withstand mechanical impacts associated with installation, for example access on foot or with a vehicle for material transport.

Floor assemblies

When do I use Schlüter®-TROBA, Schlüter®-TROBA-PLUS or Schlüter®-TROBA-PLUS-G?

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The Schlüter®-TROBA membrane is used for covering assemblies that involve loose gravel. In contrast, Schlüter®-TROBA-PLUS is designed for screed assemblies and Schlüter®-TROBA-PLUS-G is used in assemblies with single-grain screed/drainage mortars or stilted assemblies.

Contact Schlüter-Systems Ltd

Units 3-5 Bardon 22,
Beveridge Lane, Coalville,
Leicestershire, LE67 1TE
Phone: +44 (0) 1530 813396

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Further information

on our products and specifications can be found here:

Legend "Products"

We use the following symbols and abbreviations to illustrate our price charts.

image image

= new products

= radius perforation available   


H = height
L = length
B = width

PL = euro pallet 
KV = case packaging 
BV = bundle (there is a 10 item bundle packaging for all the profile types)
P = box packaging 
R = roll
St. = unit