How best to waterproof my round-about retaining wall?

[davidh95]

How do I best water proof the inside of this round about before I fill it in as a garden bed? Just going to use Betta Bitumen Membrane. Would that be OK? Or need priming first??

Was then going to line with black plastic before filling with soil. There is an aggy drain running down the centre. It is rendered on the outer side

  

 

[MitchellMc]

Hi @davidh95,

A Bitumen membrane would be fine, and no priming is required on a masonry wall. The additional layer of Builder's Plastic would be a good assurance as well.

Please let me know if you have any questions.

Mitchell