Terrace with drainage mortar 4

on open ground - terrace / driveway - with drain gutter - ceramic tiles, natural stone and clinker bricks

Terrace with drainage mortar 4

Why the Staenis grid

Tension and moisture are the 2 biggest causes of damage to a terrace. This terrace floor construction with drainage mortar allows the moisture to drain off and is tension-free due to the Staenis grid, so that the tiles and grouting remain in top condition.


  • Achieving a perfect end result without any experience
  • Replaces a drainage mat = savings of an average of 17 euros/m²
  • Replaces an uncoupling mat + glue = savings of an average of 20 euros/m²
  • Replaces the iron reinforcement net = savings of an average of 3 euros/m²
  • No expansion joints needed in the screed = savings of an average of 3 euros/LM
  • Floor construction avoids rising damp/capillary effect from the substrate
  • Water/moisture can quickly drain through the drainage mortar
  • No chance of the screed silting
  • Compartment of the screed = crack-free screed
  • No dishing/cupping of the screed = perfectly flat screed
  • Very load-bearing surface due to vibrated layers underneath
  • Spread floor works over several days (no stress during installation)
  • Very good adhesion to the tiles, by applying a fine layer of screed to the drainage mortar. Ideal for gluing tiles or natural stone
Terrace with drainage mortar floor construction

Floor construction manual

  1. Dig out the open ground, place a drainage pipe and fill it with 10 to 20 cm of concrete rubble, place it under a slope and vibrate it with a vibrating plate. Ensure now eventually that the gutter is placed in stabilised sand.
  2. Place a sloping filling layer of drainage mortar, leaving about 7 to 8 cm to adjust the height of the grid.
  3. Place the Staenis grid and determine the correct height of a leg every 3 m with a laser and place a long line on it or use a rope. This way you can easily adjust the height of the intermediate legs with a screwdriver. Provide 1.5 to 2 cm slope per running metre (depending on the roughness/unevenness of the tile surface). Place edge insulation around the screed to allow it to expand and contract.
  4. Start by pouring the drainage mortar on to the legs. In this way the height control of the grid remains correct. Then completely fill in space by space with drainage mortar. Flatten the drainage mortar with a large flat trowel (60 cm length) on the grid. Prepare a small amount of screed and sprinkle it wet in wet as a thin layer on top of the drainage mortar. Polish with a large sanding board. This ensures that the remaining holes are filled and a good bonding strength to the tile is guaranteed.

Side view floor construction

View this floor construction in reality via Sack Zelfbouw


  1. open ground
  2. Concrete rubble layers vibrated with vibrating plate (the thicker the stronger)
  3. Drainage pipe connected to drain
  4. Drainage gutter
  5. Drainage mortar filling layer (fine gravel with cement)
  6. Stainless steel grid (thickness of 7 to 8 cm)
  7. Edge insulation
  8. Drainage mortar (fine grave with cement) + screed top layer
  9. Double bonding with S1 flex tile adhesive (S2 not allowed)
  10. Floor tiles
  11. Water-resistant, coloured joint mortar
  12. Silicone
Draining terrace 4

Placement video

Placement of the Staenis grid

Installing drainage mortar terrace

Calculate the quantities and visit our webshop

Staenis webshop

You can find all products/articles related to floor structures on this webshop.

  • Such as screed, stabilised sand and drainage mortar supplied in a silo
  • (tileable) insulation screed supplied in bags
  • Recycled cellular concrete granules supplied in bags.
  • As well as the installation material to place these flat, such as the Staenis grid, sanding board and screeding iron.
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