Cement/Mortar/Concrete effect on PVC sheathing

[JohnD]

When rectifying damage to switches and sockets following a burst pipe, we found a cable embedded in a concrete floor that had an live/earth short, somewhere under this floor. The person with me claimed that the cement content erodes or perishes the PVC. He also asserted that you must not let mortar, e.g. when fixing backboxes, get onto the PVC sheathing as it will damage it.

Is this true?

 

[RF Lighting]

I've never heard of that or seen any evidence of it.

It's more likely that there has been mechanical damage to the cable which has only become apparent since the concrete has got damp.

 

[westie101]

We've been putting PVC covered cable in the ground since the 1970's, whatever the ground conditions or type, with one exception, I have never seen any deterioration of the sheath.
The exception was in chemical polluted ground at a local factory.

 

[1john]

Damaged cable either installed or damaged after installment (carpet grippers, fixings on the sole plate of a stud wall) or the slab has cracked and shifted thus damaging the cable I have never seen any damage to PVC from cement and have pulled quite a bit out over the years.

 

[JohnD]

Thanks!

I also think there must have been some other damage, and the water had got into it.