Terrace with sloping concrete slab

Terrace 8 - Choose a different floor structure

4.5 to 9 cm - sloping concrete slab - terrace/driveway - with drainage channel - ceramic tiles, natural stone and pavers

For a high-quality terrace on a sloping concrete slab, we recommend the StaenisGrid in combination with drainage mortar.

Information

Tensions and moisture are the two main causes of damage to a terrace. This terrace floor construction with drainage mortar allows moisture to drain away and is stress-free thanks to the StaenisGrid, keeping the tile and joint work in top condition.

Advantages

Achieve a perfect end result without experience
Replaces a drainage mat = average saving of 17 euros/m²
Replaces a decoupling mat + adhesive = saves an average of 20 euros/m²
Replaces the steel reinforcement mesh = saving an average of 3 euros/m²
No expansion joints required in the screed = saving an average of 3 euros/LM
Floor construction prevents rising damp/capillary action from the ground.
Water/moisture can quickly drain away through the drainage mortar.

No risk of clogging of the screed
Compartmentalization of the screed = crack-free floor screed
No dish formation of the screed floor = perfectly level screed
Very strong subsoil due to compacted layers underneath
Spreading floor work over several days (no stress during installation)
Very good adhesion to the tiles by applying a thin layer of screed on the drainage mortar. Ideal for bonding tiles or natural stone.

View all technical advantages

Floor construction manual

Terrace on sloping concrete slab with gutter

1. Place the StaenisGrid and determine the correct height of a leg every 3 m using a laser, then place a long batten on it or use a string. This way, you can easily adjust the intermediate legs to the correct height with a screwdriver. Ensure a slope of 1.5 to 2 cm per running meter (depending on the roughness/unevenness of the tile surface). Place edge insulation around the screed so it can still expand and contract. When connecting to solid ground, it is best to place a drainage pipe and fill it with 10 to 20 cm of concrete rubble. If necessary, now install the gutter in stabilised sand. 2. Start by pouring the drainage mortar onto the legs. This ensures that the height adjustment of the grid remains correct. Then, fill each compartment completely with drainage mortar. Level the drainage mortar with a large trowel (60 cm in length) on the grid. Prepare a small amount of screed and sprinkle it as a thin layer on top of the drainage mortar, wet-on-wet. Polish this with a large float. This ensures that the remaining holes are filled and guarantees good adhesion strength to the tile. 3. Tip: the drainage mortar (in the StaenisGrid) in this floor build-up can also be replaced by a sand-cement screed with a drainage mat such as Schlüter Troba-Plus 8 just below it, and a bonded draining mat such as Schlüter Drain 8 on top of the sand-cement screed. 4. Tip: Place a plastic sheet over the freshly laid screed to prevent it from drying out too quickly and becoming sandy. 5. Permitted floor coverings: natural stone, ceramic tiles, and brick pavers. Always follow the installation instructions of both the floor covering manufacturer and the store where the purchase was made.

Terrace text guide Full terrace guide Frequently asked questions Blogs about terraces

Side view of floor structure

View this floor structure in real life via Sack Zelfbouw

Legend

Open ground
Concrete rubble layers compacted with a vibrating plate
Drainage pipe connected to drain
Concrete slab
Drainage channel
StaenisGrid (thickness of 7 to 8 cm)
Edge insulation
Drainage mortar (fine gravel with cement) + screed top layer
Double bonding with S1 flex tile adhesive (S2 not allowed)
Tiles
Water-repellent, colored joint mortar
Silicone

Side view of floor construction with screed

Legend

Open ground
Concrete rubble layers compacted with a vibrating plate
Drainage pipe connected to drain
Concrete slab
Drainage channel
Draining mat (Schlüter Troba-Plus 8)
StaenisGrid (thickness of 7 to 8 cm)
Edge insulation
Vertical draining mat (Schlüter Drain 8) and edge insulation
Screed with 250 kg/m³ cement
Bonded draining, tileable uncoupling mat (Schlüter Drain 8)
Double bonding with S1 flex tile adhesive (S2 not allowed)
Tiles
Water-repellent, colored joint mortar
Silicone

Installation of the StaenisGrid

More information about the thickness of the layers

Choose a different floor structure

Installation video

Placement of StaenisGrid

Placement of drainage mortar for terrace

We deliver drainage mortar and screed in a silo to your home (only in Belgium)

Screed and drainage mortar delivered in a silo to your home in Belgium

With a simple press of the button on the silo, you produce fresh drainage mortar or sand-cement screed at a rate of 3 m³/h, and this without time pressure to process the large quantity of mortar.

There are actually 2 separate compartments in the silo. One part is filled with porphyry (2-6mm) or sand (0/4-0/7mm), and the other part is filled with dry cement (250kg/m³). These are only mixed with water at the moment you wish.

The big advantage of this is that you can create fresh drainage mortar or sand-cement screed at your own pace and for several weeks.

Purchase drainage mortar in a silo Purchase screed in a silo

We deliver drainage mortar in bags to your home

Drainage mortar delivered to your home in bags

Cem Classic: drainage mortar, now conveniently packaged in bags. This can be used/applied in the same way as drainage mortar from a silo, but with the added advantage that it is three times lighter. This property makes processing significantly easier. Ideal for creating a water-permeable base for small or hard-to-reach terraces.

Buy drainage mortar in bags

We deliver screed in bags to your home

Fast: Fast-drying, fiber-reinforced screed with only 2/3 of the weight compared to traditional screed. This makes the work significantly less heavy when working with bagged material instead of traditional screed. Ideal for applying a bonded screed floor or for small spaces, both indoors and outdoors. This Fast screed is easy to spread, allowing you to achieve a flat finish more quickly.

Purchase screed in bags

Special sealant for joints between ceramic tiles

Special joint sealant for expansion and connection joints in ceramic tiles

Because this joint sealant looks just like a cement joint, the product can also be used as a replacement for conventional grouts.

Scope of application when grouting 2 cm thick ceramic terrace tiles with a 3 mm joint.

This joint sealant is super flexible and adheres extremely well to the side of the tile. The joint also does not discolor when moistened, which looks aesthetically pleasing.

Buy this tile grout silicone here