ᐅ Retaining Wall 60 cm High – Is a Foundation Necessary?

Created on: 13 Mar 2024 13:44
M
Mateo84
Hello everyone,

I recently built a new house and am now filling my garden with topsoil. On the street side, I have 18-25cm (7-10 inches) of fill to reach the terrace level.
My plan is to build a retaining wall using masonry blocks.

I would like to have a foundation trench excavated as part of the filling process. It should be 50cm (20 inches) wide and about 20-30cm (8-12 inches) deep (topsoil layer).
Then I want to compact the sand and raise/compact it with a mineral mixture to height, and set the blocks in lean concrete with a back support.

Would this be sufficient for 2-3 courses of blocks (30-50cm / 12-20 inches + 10cm (4 inches) in lean concrete), or do I need a proper foundation of 40cm (16 inches) or more with pouring—even at this low height?

Best regards
M
Mateo84
8 May 2024 12:01
Hello,

just a quick question:

I am going to fill up with 30 cm (12 inches) of soil against the stones.
Now, I have often read online that you should place a dimpled membrane (some use fleece) between the stone and the wall.

Can someone explain whether I need to do this? I mean, I have already concreted the stones, and water will come from above anyway.

Do I have to or should do this, and if so, what is the purpose?

Thank you very much.

Best regards