Frost Depth

[jochav52802]

Good Day,

Our client who is a structural engineer, made a comment that the bottom of our shallow foundations shall be based on the underside of our slab-on-grade, rather than from the top of slab or grade elevation.

Is it standard practice to exclude the cover/frost protection provided by the depth of surface level pavements or slabs? Is there any explicit direction provided by IBC that I may have missed.

I'd appreciate any support you could provide.

Thank you!

 

[Enable]

Not that I am aware of. But I have detailed it in a similar fashion when I have a concern that the on-grade element might be ripped up in the future. Moreover, fill around houses tends to settle quite a bit (not usually well compacted) so it's best practice to allow for some additional frost depth at the start (assuming this is a house and we have no basement).

 

[jochav52802]

Thank you Enable!

 

[HTURKAK]

The frost depth ( by definiton ) the maximum depth to which frost penetrates the earth and measured at grade . That is, ( at least ) the perimeter footings/ foundation shall extent below frost line.