PVC Conduit Coverage

[Lmeagles36]

Per NEC, what is the minimum required burial for PVC conduit under a common 4" interior concrete slab???
It seems as if table 300.5 column 3 only applies for without concrete encasement. Technically my concrete isn't "encased" but it will be surrounded with stone and have 4" of concrete above it.
I'm thinking it would either be considered under the building since it will have 4" of concrete over it, or it would have to be 12" under the top of the concrete per the next row up on the 300.5 table.

 

[jumper]

Under the building. 0" needed. We used to just stake the small 1/2', 3/4", and 1" right on top of the base layer (gravel, dirt, etc).

 

[infinity]

As Jumper stated, in T300.5 under a building in all instances is 0". The 4" would be for an exterior slab.

 

[Lmeagles36]

I'm sure the NFPA did its homework before producing this burial depth table, but to me it seems a little too close.
For instance, a typical interior 4" concrete slab having PVC conduits directly underneath it with no additional coverage besides the 4" of concrete... and then a plumber comes along to trench cut the concrete to extend a sanitary or domestic water line in the future... I'm sure they would set their concrete saw depth 1-2 inches deeper than the slab thickness, and would cut right into the PVC Elec conduit without even knowing right away.

Is my thinking incorrect in this case?

 

[kwired]

I'm sure the NFPA did its homework before producing this burial depth table, but to me it seems a little too close.
For instance, a typical interior 4" concrete slab having PVC conduits directly underneath it with no additional coverage besides the 4" of concrete... and then a plumber comes along to trench cut the concrete to extend a sanitary or domestic water line in the future... I'm sure they would set their concrete saw depth 1-2 inches deeper than the slab thickness, and would cut right into the PVC Elec conduit without even knowing right away.

Is my thinking incorrect in this case?

And if you cut into floor to install electric lines and there is a plumbing line in there you damage it also:happyyes: