Footing depth

[ICE]

Fatal mistakes are sometimes a real surprise. This work is set up with girder pockets but the dirt inside the footing is too high. To achieve the required 12" clearance to dirt. So much dirt will have to be removed that the required depth into undisturbed soil will be short by 8". The forms and steel will come out to enable them to dig deeper so am I wasting my time by writing a host of corrections?

The other setback is the service drop. They will need a temporary power pole before they start framing.

 

[Paul Sweet]

They could use treated lumber for the girders, and excavate at a slope from the footing.

 

[Mark K]

Does the code say into undisturbed soil or must the bottom of the footing be a certain depth below adjacent soil. We apparently are in Southern California so freezing soil is not a concern. Go with what the code says but if there is flexibility in interpretation you might measure the depth below undisturbed soil as being the depth below original grade.

If the soil is dug out to provide the clearance under the joists (18") and beams (12") will it possibly be lower than adjacent grade. Is there not a requirement that there be a way for any water that accumulates to drain out? While this is likely governed by the CRC is there not a requirement comparable to CBC Section 1805.1.2

 

[ICE]

Mr. Sweet,

Yes that was a possibility that would have to include the floor joists as well.

Mr. K,

Undisturbed soil is not always the original grade because sometimes the soil has been removed. Undisturbed means just that, undisturbed. Water doesn't get in so there is no problem getting water out. If water were to find a way in, it would soak in, evaporate or cause mold and maybe all three.