ᐅ Installing polygonal paving slabs over an existing terrace (concrete slabs)?

Created on: 11 Apr 2020 13:07
G
Gatho
G
Gatho
11 Apr 2020 13:07
Hi!

In 2017, we moved into our newly built house. The purchase price included a typical concrete slab terrace (see photo).

Paved patio made of gray rectangular slabs, grass on the left, planter on the right, shadow over stones.
Size 4 x 9 m (13 x 30 ft) plus a corner section leading to the garage (approximately 5 m² (54 ft²)).

The slabs were laid on a gravel bed (see photo from “back then”).

View through glass door of steps made of paving stones leading to a grass-covered garden behind a fence.


Since we already have a high step into the house (about 19 cm (7.5 inches)) and now want to enhance the terrace with polygonal stone slabs in a Mediterranean style, we are wondering if we can use the existing concrete slabs as a base? The slope is already ideal, and our thought was that the concrete slabs provide a solid foundation for our project.

Is this feasible, and is there anything special we need to consider given our situation?

Good luck & many thanks!
H
hampshire
11 Apr 2020 13:23
It should fit, as it is indeed a rather elaborate, stable, and level base.
S
Steven
11 Apr 2020 14:18
Hello Gatho

Set the curbstones level (the “old ones” can stay). Make sure to have a 2% slope. Add gravel on top, level it carefully, and then lay the paving slabs. It will last forever. You already have the base layer.

Steven
G
Gatho
12 Apr 2020 01:46
Hi!

@hampshire & @Steven -> thanks for the feedback!

I was actually planning to do it the way shown in this video:
[MEDIA=YouTube]EHeTvSsgE4I[/MEDIA]

Steven mentioned using a primer again. But that shouldn’t really be necessary if I apply a cement-based bonding slurry directly on my existing concrete slabs and then put the adhesive on top before laying the tiles, right? Pretty much like in the video.

Best regards and thanks!
H
hampshire
12 Apr 2020 02:32
You don’t need gravel when using cement slurry.
S
Steven
12 Apr 2020 08:45
Gatho schrieb:

But it’s actually not necessary if I apply a cement bonding slurry directly onto my existing concrete slabs

Hello Gatho

If the build-up with bonding slurry and adhesive works, you don’t need any gravel.
How much higher do you need to raise the new panels?

Steven