ᐅ Raised Terrace – Protection of the House Wall – Is Waterproofing Required?

Hello everyone,

The positioning of our house and the topography of the surrounding land require us to raise our terrace by about 40cm (16 inches), at least if we want to have level access from our living room to the terrace. This means that we / the landscaper will proceed as follows:

- Foundation plus retaining wall for the terrace with planter boxes or similar (height about 40cm (16 inches)) in a U-shape
- Terrace area excavated with crushed stone and compacted (width 7m (23 feet) + depth 3.5m (11.5 feet))
- Installation of paving slabs on a layer of gravel

Now my question:

At the wall junction (located about 10cm (4 inches) below the base of the house), the landscaper wants to install only a dimpled membrane to prevent the crushed stone from directly touching the house wall (no basement). Is this sufficient, or should an additional waterproofing layer (besides the base coat plaster) be applied or installed?

Thank you for your opinions.

Best regards
Grobi

Plaster or brick veneer facade?
Wall construction with which insulation?
How high were the vapor barrier and window sealing extended on the interior wall structure?

Dimpled membrane does not provide waterproofing; its main purpose is to protect a waterproofing layer from mechanical stress. At the top, water can enter without a drip edge; dimples face the soil, if ventilation is not required.

For brick veneer, I would use a slurry waterproofing or a two-component bitumen thick coating. EPDM membrane with adhesive is also extremely durable and quick to install but is not inexpensive.

If it was built correctly, the mason should have applied a waterproof slurry twice, about 50cm (20 inches) high, under the base plaster. Starting from the stone at ground level. K.

Otus11 schrieb:
Rendered or brick facade?
Wall structure with which insulation?
How high was the vapor barrier and window flashing applied on the inner leaf of the wall?

Wall structure: 42.5 cm (17 inches) insulating masonry block, no external insulation, with a rendered facade.
The membrane was extended up to the bottom edge of the window, meaning it would cover the backfilled area.

Nordlys schrieb:
If the masonry was done correctly, a waterproof slurry should have been applied twice to about 50 cm (20 inches) high under the base coat by the mason. Starting from the ground onto the block. K.

That was done, but not by the mason—instead, by the plasterer.

See, this way you can trust the landscaping contractor.