How Much Rebar in Foundation Drainage pipes, concrete, footings and foundations. Post your questions and find answers here

[Poe]

Hi all,
I'm building a large (215mm) think garden wall.
The foundations are 32cm deep and 50cm wide. 17.5m long before turning a corner and continuing for another 12m.
I plan to use rebar due to the size of the foundation but could someone tell me what thickness I should be using and how many bars across the width should I use.
Many thanks,
Poe.

[stoneyboy]

Hi Poe,
A lot will depend on the ground conditions under the foundation and whether it is a freestanding or retaining wall.
Regards S.

[Poe]

The ground is firm clay and the lower section of the wall will be retaining 30-40cm of soil.
Total hight of the wall will be 5-6 foot max.
Cheers, Poe.

[stoneyboy]

Hi Poe,
That is one hell of an undertaking. I suggest you contact a structural engineer for suitability on foundation depth.
Assuming your foundations will be deep enough to avoid the issues of clay expansion/contraction I would suggest you use strips of 4/5mm weld mesh embedded within the concrete.
Where you have a retaining element you will need to increase the width of the foundations with the widest part on the retaining side.
You will also need an expansion joint on each side with stainless reinforcing bars in the mortar courses.
I would repeat you do really need professional on-site advice.
Regards S.