Sewer smell in home from adding to soil pipe

[cool_dude_2000]

Really struggling with this now...

The external soil stack vent doesn't appear to be blocked.

I have disconnected the waste pipe from the wash basin in the loft in case that is causing a vacuum. There are now open waste pipes for the shower and wash basin up in the loft and connected to soil pipe.

I have checked the gully trap in the shower on 1st floor. There is a bit of water trapped inside which falls below the outlet hole. Flushing loft toilet has no effect.

 

[Chuck]

There are now open waste pipes for the shower and wash basin up in the loft and connected to soil pipe.

This is not a good idea. Sewer gas is potentially toxic/asphixiant and explosive and you are allowing it into your house.

I recommend that you reinstate the traps, and stop using the new attic bathroom until the problem is sorted out properly. Make sure the rooms that have experienced a smell are well-ventillated and call a plumber who knows how to pressure test your system and perform a smoke test if, as I suspect it will, it leaks.

Further information about sewer gas:

Sewer gas - Wikipedia

 

[cool_dude_2000]

Thanks, will do. Funny thing is that there is no smell coming from the disconnected outlet pipes in the loft.

 

[justlead1]

There is no mention of ground floor. (Soil connection to drain)
Then boxing formed around pipes can act as a duct. The area that smells may not be the area of problem regarding pipes.

 

[cool_dude_2000]

Yes possibly. I have a plumber coming round this morning to check and will hopefully locate the issue. I do suspect a vacuum is the issue as the sink in the loft gurgles as the waste goes down, and the water in the 1st floor bathroom sink is very slow to go down the plughole.

 

[Chuck]

Yes possibly. I have a plumber coming round this morning to check and will hopefully locate the issue. I do suspect a vacuum is the issue as the sink in the loft gurgles as the waste goes down, and the water in the 1st floor bathroom sink is very slow to go down the plughole.

It's possible the gurgling, is a separate issue. Your conversion may have revealed a long-standing issue with the drain at ground level by sealing the top of the boxing. This could have previously been venting the smell into a (draughty?) roofspace where it wasn't noticed.

I'll be interested to learn how your plumber tackles the problem. Do report back and good luck.

 

[cool_dude_2000]

Ok, plumber has taken a look and suspects a drain blockage as his jet wash pipe cant proceed beyond a certain point from the mancover access. Flushing a tissue down brings slow release of water out but no tissue. Has to be rebooked with a camera to investigate further.

Comforting to know its not a venting issue - but has opened up another can of worms!