ᐅ Construction of a Terrace on a Concrete Slab

Created on: 10 Jul 2025 17:18
M
MurphyBS99
M
MurphyBS99
10 Jul 2025 17:18
Hello everyone,
we are planning to redesign our terrace. So far, it is covered with concrete slabs, and we would like to replace them with porcelain tiles.

There is a concrete slab underneath the current terrace.
The total thickness up to the top edge is about 17 cm (6.7 inches).

The current structure consists of approximately 8 cm (3 inches) of crushed stone with gravel and the concrete slabs on top.

Since we want to fix the new terrace tiles firmly, I plan to lay them wet-on-wet in drainage concrete.
My question is: Do I still need a drainage mat between the crushed stone and the concrete slab, or could the drainage mat be installed between the crushed stone and the drainage concrete?
A plastic membrane was installed under the concrete slab originally.
The house wall will be waterproofed again, and I want to place an insulation strip between the wall and the crushed stone/drainage concrete to decouple the structure.

Does this setup seem appropriate?