Block Wall - Piers and Movement Joints

rhennessy

Hi,

Starting to look for block layer to build 90m of 4" block on flat to approx 700mm high. Max continuous length will be 30m with a number of other smaller sections. It will be used to separate a lawn from the back yard where the lawn is about 600mm above finished ground level. I have 2 questions:
1) Do I need piers considering the wall will be block on flat and relatively low?
2) Do I need movement joints?

The wall will not be subject to any real wind loads (site is very sheltered) and also is not retaining anything of significance.

Just want to be prepared for when I talk to potential block layers.

Thanks

Gumbo

rhennessy wrote: »

Hi,

Starting to look for block layer to build 90m of 4" block on flat to approx 700mm high. Max continuous length will be 30m with a number of other smaller sections. It will be used to separate a lawn from the back yard where the lawn is about 600mm above finished ground level. I have 2 questions:
1) Do I need piers considering the wall will be block on flat and relatively low?
2) Do I need movement joints?

The wall will not be subject to any real wind loads (site is very sheltered) and also is not retaining anything of significance.

Just want to be prepared for when I talk to potential block layers.

Thanks

Considering your engineer had ruled out wind loading and retaining capabilities, surely he/she would design the locations of piers?

Calahonda52

Just to flesh out the design issues

What do you mean by: is not retaining anything of significance.

First question: what is the soil like for the foundations:?
Whats the foundation design, including reinforcement?
How far down below ground level will the block work start, allowing for frost heave?

What depth of material will be against the wall from top of foundation on the high side?
What is the drop from top of wall to soil on low side?
What provision will be made for water drainage from the retained material?
Is the location higher or lower than the surrounding landscape?
By this I mean where do you think the water table will be in mid winter after heavy rain?
...

Having said all that piers and movement joints would be not more than every 6m.
The rule of thumb for the foundation would be 3 times the wall width so in this case just stick a meter wide bucket on the digger.
The strip should be al least 300mm deep with some rebar
Your sheltered site may be more prone to frost so you may need to go down a bit, maybe a meter below the lower level

http://www.environ.ie/en/Publications/DevelopmentandHousing/BuildingStandards/FileDownLoad,1639,en.pdf
will keep you out of the pub!