Concrete stumps

[simon1969]

I have to put in some concrete stumps for my extension , I know how much concrete I have to put for the pad but I can't find anywhere that tells me the size and depth of hole needed . Can anyone help me with this ?.

[RETIRED]

A question better asked in here, our sister site:Renovate Forums - Home

[Bedford]

The size and depth of the hole is determined by the soil test/engineers report.

This information should be available from your approved plans.

[rwbuild]

The size and depth of the hole is determined by the soil test/engineers report.

This information should be available from your approved plans.

Correct, that is the only allowable method that the certifier or council / engineering inspector will accept and pass

[rwbuild]

I have to put in some concrete stumps for my extension , I know how much concrete I have to put for the pad but I can't find anywhere that tells me the size and depth of hole needed . Can anyone help me with this ?.

How do you know how much concrete for the pad if you dont know what size hole has to be excavated LxWxH = volume

If you know the quantity then your question should be "what depth do I excavate to to achieve the correct bearing"
NOTE all the piers MUST achive the same bearing value ie: if one is rock / shale then all must be rock / shale, if clay / alluvial it is either H (highly reactive) M (moderately reactive) S (stable).

The engineers design SHOULD specify which classification it is and the pads designed accordingly

[DaveTTC]

Some shires / councils will give a minimum depth and diameter in the absence of engineer specifications

Typically 450 across and 1100 deep from memory.

Again from memory and only to serve as an example they may specify un-reinforced concrete minimum 200 mm deep under stump allowing rest to be back filled with soil

Like said. Check the other forum


Dave

The Turning Cowboy