Block on flat x 10 meter x 1 metre query.

[Thebull]

When building this would an expansion joint at 5 metres be sufficient? The wall will retain soil , I could add piers for support if necessary but hoping block on flat will suffice. Thanks in advance

 

[noseall]

When building this would an expansion joint at 5 metres be sufficient? The wall will retain soil , I could add piers for support if necessary but hoping block on flat will suffice. Thanks in advance

The last retaining wall we built at 1m tall was (architect designed) 325mm thick at the base, reducing to 215mm. 7n blocks laid flat with a brick facing, plus weep holes, perf pipe and gravel and painted with black jack at the back. Ex-con joints every 4m I think.

 

[robinbanks]

The wall will retain soil , I could add piers for support if necessary but hoping block on flat will suffice

You didn't say what height

 

[noseall]

You didn't say what height

Apart from the thread title?

 

[noseall]

You didn't say what height

I'm the worst for only reading part of a thread or post. Guilty.

 

[Thebull]

no problems. Yes it's one metre high.

 

[robinbanks]

And the profile of the soil is it level with the top of the wall, sloping down as it goes away from the wall or sloping up as it goes away from the wall?

 

[Thebull]

It's about 2 courses shy of the top of the wall. Everything runs down hill so wall will probably need supported unless block on flat can contain it safely. Thanks

 

[robinbanks]

The soil runs down hill away from the wall?

Single leaf block on flat will be fine. Use eg eBay item number 303659318361 to bridge the expansion joint.

 

[stuart45]

A 9 inch retaining wall can fail in certain ground conditions. Here's one I priced up about that height in heavy clay and the the ground running up from it.
The traffic control made it really expensive.

 

[Ivor Windybottom]

Best to overdo expansion joints, especially as you know it's going to be saturated wet in winter, shrinking to bone dry in summer - this is far more demanding than a house wall.

Put two in, at whatever block units gives you something near to thirds. Slightly more work than one, but the penalty for using one could be a massive crack through the thing.