Rising Wall / Block Dims

[Paul15]

Hi All,

 

I have a question regarding block foundations dimensions found in the substructure. Say for example the external walls above DPC are a 300mm cavity - 100mm block / 100mm cavity / 100mm block; will this be the same for the rising walls built of foundation below DPC generally or is it practice to build a wider block footing to accommodate?

 

Likewise 100mm block internal walls - will the 100mm block generally be built from top of concrete foundation or are block footings wider?

 

Hope I make sense.

 

Appreciate any comments!

 

Thanks

 

Paul 

[Declan52]

You can build the outside walls of the foundation 315mm wide no problem. It will be 315mm as you will have a block on it's flat then one on it's edge of you use standard blocks but most block companies do foundation blocks that you can get 300mm wide or even wider if you want. You can if you want build them wider but it's not really needed. 

For the inside walls you usually build it up with a 215mm wall, block on it's flat, and then the very last course will be 100mm. A 100mm wall wouldn't stand up to getting backfilled with stone without it moving slightly.

[Paul15]

Thanks Declan that fantastic explanation cheers.