Tanking behind a retaining wall?

================= I think the suggested membrane is to prevent the bricks deteriorating rather than to create a 'tanked' enclosure. I don't think the wall could be described as 'tanked' since it's got drainage holes. My front garden wall was built more than 60 years ago without a membrane and it's still in good condition. You're not building Hadrian's Wall so go ahead without the membrane as your concrete blocks are unlikely to suffer especially as they're sometimes used as footings.

Cic.

Ah, just what I was hoping to hear. Thanks for that.

Neil

But it may be worth your while putting a water-proof render on the outside, useing a Sika additive.

Deterioration & weeping may occur at the mortar joints. The cost of 1 roll of Visqueen or equivalent is very low. Cormaic's advice is usually spot on so I _would_ use it.

OK, thanks for the advice chaps.

You also need to drain the water out the bottom on the wall. The soil is not heavey, but the water is.

Rick

Aparently the water forces this off the wall, the waterproofing has to be on banked side.

Rick

deteriorating

was hoping to hear.

on banked side.

Um that?s what I meant, outside=earth side.. but obviously didn?t say it clearly enough. ;-)

Toby wrote

I don't know about the weep pipes though. Can you actually get 20mm copper pipe? And in a damp situation like this, in direct contact with cement, the copper won't last very long at all unless it's protected. I think I'd go for plastic myself.

Peter

Sounds spot on, my folks had a wall that just uses mortar gaps. Been there