Sewage smell around new groundworks

[vexation]

Our building contractor has nearly completed block & beam floor which spans over an existing sewer pipe. Having just had a quick look around before everything is covered in screed we noticed said smell that wasn't there before. What's the best way to raise the obvious concern that someone may have accidentally damaged the pipe without being annoying (it may not be what we fear) or implying a lack of trust (we get on well).

 

[Ian H]

Tell him it smells, suggest a dye test and smoke test to check for leaks.

If it’s an old clay pipe it could have been leaking air/water already.

 

[vexation]

Thanks. I wondered about using dye to reveal a leak. The pipe is fairly new plastic one and was bridged over with a lintel. The foundation trench has been backfilled so it would need digging out to see the pipe.

 

[lostinthelight]

The foundation trench has been backfilled so it would need digging out to see the pipe.

What about a drain camera?

 

[Ian H]

I’d be surprised if it was a fault in the plastic pipe.

Is the drain work finished? Any open ends or access caps missing off gully’s?

 

[lonner]

Pressure test is the easy way to check for a leak

 

[vexation]

Got it! Blocked drain overflowing out of sight, around the corner. Crazy coincidence.