Single skin blocks strong enough for raised planters

by **Dmoblay** » Sat Aug 29, 2020 6:44 pm

I’m building two raised planters. Their height will be about 500mm above ground level. 600-650mm in total.

one of the planters is 1.8m wide and the other is 5m wide. Both are 1.1m deep (front to back).

im using concrete blocks, laid on a concrete footing which is 400mm thick. The soil underneath is light clay.

Will single skin be strong enough? Or do I need to make them double thickness?

by **stoneyboy** » Sun Aug 30, 2020 10:19 pm

Hi dmoblay
At 600mm high a 100mm thick wall will not survive more than a few years. Suggest you use 150mm thick blocks and form a double thickness internal pier at the centre of the 5m planter.
Regards S

by **Dmoblay** » Mon Aug 31, 2020 5:44 am

Thanks for the reply. What about the 1.8m one? Will that be ok?

by **stoneyboy** » Tue Sep 01, 2020 9:18 pm

Hi dmoblay
Still suggest you go for 150mm but you could try 100mm and if it cracks in a few years rebuild it.
Regards S