The Brew Cabin

Posted: **Wed Sep 17, 2008 3:18 pm**

Hi Everybody,

I've been asked to build a 60cm retaining wall to surround a patio. The wall is next to a planting bed which is next to a 6ft wall. The patio level & the visible base of the 60cm wall is 38cm below and 1m away from the top of the foundations of the 6ft wall.
please refer to the image.

What I want to know is...
1. A builder friend of mine says that the foundations have to be at least 40cm deep to cope with the additional weight of the existing wall. Is this correct?
2. how many courses should be below ground (ie, proposed patio level)?
3. would it be appropriate to use blocks with butterfly ties with a brick face to save on brick costs?
thanks folks! I'm a bit out of my depth!

Posted: **Wed Sep 17, 2008 10:57 pm**

hard to say without a site visit but what you have drawn looks ok,only an architect or engineer can tell you 100%
if you use blocks make sure they are concrete and nothing else
cheers LLL

Posted: **Fri Sep 19, 2008 6:35 pm**

we use 100mm dense concrete block (7 newton) laid flat and then ties for face say stone or brick on a 400-600 footing, depth depends on the ground condition.

if you really retaining a lot you can set rebar into your footing and use hollow block over the the rebar then back fill with concrete, but as Lll says consult an engineer its what they're for.

Posted: **Sat Sep 20, 2008 9:15 am**

Great!

Thanks for that! rebar option with hollow block sounds good! I'd been considering that one!

bert!

The Brew Cabin

Retaining wall - Extra load consideration