Retaining wall - Should i put drainage in?

[Spitfire]

Big fan of the site, thanks for the tips!

Recently i was queried about is any form of drainage necessary when putting up a retaining brick wall??

To set the scene:

patio is being extended out further into garden, 3m out 10m across, existing retaining wall taken down, new one erected one metre further back. Lawn height is 400mm higher than the finished paving level will be.
I know where my falls are going, i always ask the customers if they have had any water problems in the past. Customer said no, and later that afternoon someone in the pub curiously asked me does a drainage system always have to be in place or is it only in worst drainage cases?

If i am meant to be putting drainage in/behind retaining walls is there a particular way i should be doing it?

Any info or advice would be greatly appreciated.

Chris

[Pablo]

Retaining walls always need drainage.

[matt h]

see main site for perforated drains.

[Spitfire]

Yep found the stuff on fin drains etc, will be doing that. Just a pain that hardly any builders merchant dont stock it in-store in surrey!

Thanks for info lads

[Pablo]

Fin drains might be a wee bit over spec for what your after. If you need to remove surface water then think about linear channels and for sub surface water think about perforated pipe in clean aggregate with a terram fabric surround to prevent silting thats all on the main site too. Good luck

[Rich H]

And if you can get the perforated pipe to an existing soakaway all the better.