DIY Doctor

garden wall foundation

Postby gardener » Sat Apr 07, 2007 11:44 am

Hi there. I am planning a low retaining wall 4.5m x 0.5m high in my terraced house's garden. It will incorporate a step down from a planting area to a dining site. I am proposing a curved facing wall (4.5m) of yorkstone walling bricks on the lower side and backed with a separate straight wall (4.3m) of breeze blocks and rubble/gravel on the higher side to take the weight of the retained soil. I have dug a single trench, which to allow for the curve is around 1 m wide. The earth is relatively soft, non clay but I have now hit hard ground 30 cms down. There are no trees or houses within 5m of the site. Any comments/assistance on the following points?
1. hardcore base to the foundation - how deep does this need to be? I was thinking 50mm but am not sure this will be enough.
2. how deep should the concrete be? I have seen 150m mentioned eleswhere but this seems excessive for what I want.
3. Given the depth and width the trench, can I lay the a couple of courses of breeze blocks on their side (underground) on top of the concrete before laying the bricks/blocks in the usual way?

Thanks for your advice.
Rank: Labourer
Progress to next rank:
Posts: 1
Joined: Sat Apr 07, 2007 11:13 am


Simply Build It

Postby thedoctor » Wed May 16, 2007 8:23 pm

If you are on solid ground there is no need for hardcore. Concrete to foundations should always be a minimum of 150mm thick. This is not because of what is going on it but because the ground moves with heat and cold variations and this thickness is the minimum required for it all to stay together...Even then there are no guarentees. You can lay them any which way you choose !
Posts: 2528
Joined: Sat Apr 08, 2006 12:15 pm

Display posts from previous
Sort by
Order by

  • DIY How to Project Guides
  • DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!

  • Related Topics