Retaining wall in garden - Celcon blocks?

[Geo]

I have lookead at the usual paving expert page and googled for a couple of hours but have to ask another question in here... I need to build a short (about 3 feet long) earth-retaining wall which will also support one end of a bike store (6' x 3'). The wall needs to be about 28" high - from the lower ground level. Appearance is not a consideration since the face of the wall will be less than a foot from an existing garden shed. I only have access to B&Q and Wickes and found some Celcon Standard blocks in B&Q which, according to the web site, can be used as foundations as well as internal/external walls. They seem very soft and flaky and I am unsure if they would weather well without rendering. This site appear to be using something similar:-

opinions on using Celcon blocks?

Geo

[The Natural Philosopher]

Jot sure about celcon..isn't that the soft s**te you cut with a saw? I used proper concrete blocks and steel ties between every one. That worked OK. I'd use double thickenss for 28" of soil tho, and do leave drain holes at the bottom and backfill with gravel..

[Geo]

That's the fella

I can't visualise that? I was going to use the blocks on their side so 8 1/2" thick. Had thought of drain holes but not of gravel.

Geo

[robgraham]

Not sure if this is going to help - it's the 3ft long bit that worries me and probably does justify extra thickness. Anyway I built a 20m long wall 10m years ago using 6" dense concrete blocks. It is on a curve and one end is 3 courses high - ie is around 28" above the ground. Rather obviously it is still standing and looking good.

I was concerned about the build up of drainage water behind the wall and place short lengths of 15mm plastic pipe through the wall every 3 blocks. At the base of the wall I ran a length of that drainage plastic pipe ( corrugated with holes) and back filled with gravel.

Rob

[meow2222]

I daresay you could do it with all sorts of things and cross your fingers, but for a retaining wal I'd definitely be using dense blocks, not aerated. A collapsing retaining wall can be dangerous.

NT

[Steven Campbell]

Same site you linked to has a french drain

[Geo]

OK - gone off the aerated blocks. Thanks for the French drain info. The dense blocks weigh about 20kg which I think will be too much for me to handle (working from the upper level only) so am now considering either cutting dense blocks in half (with a 4 1/2" grinder??) or using B&Q clay engineering bricks at 29p each and "single brick" (8 1/2") thick wall. The short length is still a slight worry but the wall will be supporting half the weight of the bike store+base which will be about 100kg empty so this should give it some additional stability.

Geo

[The Natural Philosopher]

Wuss :-)

Get wall ties and use em everywhere. The pressure of wet soil behind is large.