Hello there, we recently had a large extention built on our cottage, which involved removing hundreds of tons of soil from behind the cottage for the extention because we are on a slope. We need to build a retaining wall to stop the soil falling down to the extention. I did the digging and have left a 1.5m pathway around it, the bank behind goes from nothing to about 10 foot on a very long slope(around 20ft wide from bottom to top). We want to build a wall 4 blocks high-3ft x a 9inch block wide. The soil is mostly rock with some clay between. I have been told that we need something like a 20inch wide foundation for 9inch blocks but we need to know how deep the foundation needs to be. The ground where the wall will go is mostly rock and I was thinking something like 6inches deep would do as it is very hard to dig. Any ideas? The wall will be in an L formation around the house, being 45ft long and 14ft wide on the short end.
Garden retaining wall+how deep do the foundations need to be
- Thread starter ademco
- Start date
Sponsored Links
If, as you say it is mostly rock then 6-8 inches may well suffice. For any major foundations the criteria is that you dig down to suitable solid ground conditions and as you have rock it seems ok. I would dig two test holes several metre apart though just to confirm if the rock is consistant.
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
Sponsored Links
