Single skin breeze block retaining wall

[garden4ork]

What are your thoughts please on the suitability of a single skin breeze block retaining wall to a height of 800mm? Laid normally as the 100mm thickness.

 

The wall length will be 9m with piers constructed from alternating railway sleepers/blocks every 1.5m.

 

Everything I've managed to get is reclaimed, other than the 6t or so of aggregate/gravel that I'm planning on getting from the council as backfill and to tamper down and use as the base/foundation. 

 

I was also wondering, you know the concrete cast flower blocks - if I laid these flat and used as my first course within the ground (filling in the flower with more aggregate) is this asking for trouble or should it be okay?

 

Cheers 

[Conor]

Not a chance. Block on flat as a minimum.

 

[saveasteading]

23 minutes ago, garden4ork said:

the concrete cast flower blocks

That is similar to a commercial retaining wall product, where the pots are sloped backward into the hill . They are filled with gravel. The issue might be durability differences between a certified engineering product and garden centre quality. I'm currently conscious of that. having had 2 fibre cement pots collapse after 4 years' use.

800 isn't high if you want to chance it and there are no dangers created in so doing. ie if it fell over, would there be any consequences? Shouldn't be near a  building or a boundary either.

 

want to send in a sketch and a photo of the block type?

 

7 minutes ago, Conor said:

Not a chance. Block on flat as a minimum.

probably step these back too.

[saveasteading]

31 minutes ago, garden4ork said:

single skin breeze block

To me a brieze block (seem to be called breeze more often) is a low strength block with cinders bulking the concrete out, and are low strength. 

As you say these are reclaimed then perhaps this is exactly what you have. If so, they will be very weak. lay flat with gravel behind each one as you rise, and 50mm step back for each layer.

[nod]

1 hour ago, Conor said:

Not a chance. Block on flat as a minimum.

 

Plus 1

Single skin will collapse while you are backfilling 

[Declan52]

Should be at least 18 inch at the bottom then step in to 13inch then step again to 9 inch then your final course can be 100mm. By doing it this way your giving your backfill a ledge to sit on which adds weight to the wall and stops it tipping over. Don't forget to lay a drain behind the wall to divert rain away. Do it once and do it right.

Not a chance a single skin wall built 4 course high will be able to hold anything back. After it rains and settles it will bulge and bulge then burst and collapse. 

[garden4ork]

Thanks for the replies so far - Pretty damning I think and will have to source some more blocks!

 

I don't mind the idea of going a bit thicker at the bottom and stepping up, as Declan says. Cantilever style. However also wary of the other idea to step each course back, which I've seen more often when researching but would leave it quite unsightly even after rendering. Any reason to do that over Declan's method?

[saveasteading]

1 hour ago, garden4ork said:

quite unsightly even after rendering

The pyramid style doesn't appeal then?  The Egyptians covered some of theirs with marble. The Inca left them stepped., and un-rendered.

[garden4ork]

20 hours ago, saveasteading said:

The pyramid style doesn't appeal then?  The Egyptians covered some of theirs with marble. The Inca left them stepped., and un-rendered.

 

I'd have to look up a few examples RE rendered but the budget isn't going to stretch to facia blocks and certainly wouldn't want it breeze block finish/painted 😔