Strange sewage smell coming from behind kitchen sink cupboard

[Chuck]

we’re waiting til the new year for the flagging to be done.

Don't complete the flagging until you had the gas pipe relaid in a position that complies with the regulations. Underground works are not my thing, but I am sure that you are not allowed to have a gas supply cutting though an inspection pit in the way yours has been.

You will need to follow the 'move a gas supply' procedures published by your network supplier. From memory of a job I've only dealt with once some years ago, the gas pipe will need to be made of approved materials and marked with warning tape, and end up 18 inches deep in a trench surrounded by (6 inches?) sand and no closer than 12 inches to other services.

Whoever did your current work, IMO, should be prosecuted. A rat will happy chew through that pipe and fill you drains with gas. If you knowingly leave it like it is, IMO, you should be prosecuted too.

Once the gas pipe is relaid safely, as I said before, you need your drains properly leak tested. It wouldn't surprise me if all the new stuff needs to be excavated and redone by someone competent.

 

[WC1]

Your water board will have a list of underground contractors who will be able to help. You might want to look at something like household insurence to help you make some sort of claim against the guys who left it like this state, scandalous, IMO. If someone made an honest mistake I'd usually say get them back and give them a chance to put it right, but not in this case. I'd keep lifting the lid every few days because you won't know if it's blocked because the waste will just leak out by the gas pipe. (which is one reason why you can't just cut into an I/C) - and it will block again because of the soil falling in at the breach. Look on the bright side, you found it, and you can put it right rather than building contol, the water board or some other body finding it - that could have caused you serious issues. You've come to the right place to get some input and you should be able to recover the cost from the other side. Merry Xmas to All and best wishes for the new year, WC1