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Foundation Width

Postby Daca » Mon Sep 19, 2011 11:21 am

Hoping someone can help with a question on foundation widths. For my new dwelling I had an enginner do some loading calculations to work out the required foundation size. The maximum loading from walls/roof/floors/wind/snow etc was 55KN. The ground was pretty good and I would estimate that it would take a bearing capacity of 100. So working this out 55/100 would give a required foundation width of 550mm. The engineer specified 650mm x 300mm strip foundations with 1 layer A393 mesh bottom (to be on the safe side)

As the cavity wall width was 350mm the builders built a 450mm wide footing on the foundation and then the 350mm cavity wall on top. My question is as follows - will the foundations be OK without a 150mm projection either side? As the footings are 450mm on a 650mm wide foundation this only leaves 100mm either side.

I know there isnt much that can be done at this stage as the house is substantially complete, but would like to set my mind at rest.
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Postby welsh brickie » Mon Sep 19, 2011 5:14 pm

ideally yes 150mm toe on each side,but the foundation is 300mm thick with reinforcing, It will be fine
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