Expansion boards for footings.

[simon1883]

Hi all,

Can anyone possibly help with my question?

I have been told that I may need to include expansion boards with my footings for my extension. How do these fit and when are they fitted?

The above is due to a tree being in the proximaty.

Cheers

Simon

 

[^woody^]

They go vertically up the side of the trench before concreting, to keep the soil off the concrete when it is poured

 

[simon1883]

Cheers.

Are they a particular type of material or can I ask the local BM for expansion boards and they'll know what I'm on about or will I look like a burk!>?

 

[^woody^]

Expansion board or clay board, they should know what you want

www.dufaylite-clayboard.com

You should be able to use normal polystyrene though

 

[Static]

The material needs to be able to compress a certain amount which depends on your soil type, normally needs to compress 25-35mm .. better to go for a proprietory system thats been tested, or you may end up having to prove your stuff in compression..

 

[Static]

Expansion board or clay board, they should know what you want

www.dufaylite-clayboard.com

You should be able to use normal polystyrene though

Isn't clayboard a below slab void former? It wouldnt be suitable beside a footing as they collapse when wet..

Check out Cordek and their claymaster system as a typical one..

 

[RonnyRaygun]

Isn't clayboard a below slab void former? It wouldnt be suitable beside a footing as they collapse when wet..

Check out Cordek and their claymaster system as a typical one..

Yeah, Clayboard for below slabs, Claymaster for the inside face of footings...

 

[^woody^]

"Clay board" is a generic term for the builders around here for this stuff.

I didn't check the link, I thought they would just have suitable products, but yes the OP needs to get the right one