Soil Stack Connection WC Bath

[Madrab]

Feels like this implies that opposed connections with swept entries don't require the offset. The WC connection is swept I think? But the bath connection definitely is not. Is that a get out for the "plumber" as we are probably going back to them with this.

Is this a new bathroom or just a refurb of an existing?

Whoever they were haven't followed some basic plumbing rules. As far as the regs are concerned then yes - they are there and are regs (in law) for a reason. This is the key section in the regs as pertains to your situation


They haven't followed basic design principles and as mentioned by @Hugh Jaleak , the bath connection directly contravenes the regs. Yes you could use that to force these guys to sort it out, how long and protracted could that be, that would be down to the company.

 

[Hugh Jaleak]

Madrab has got the requisite diagram into his post, (thanks!), which is what I was referring to previously. Opposed entries just do not work, I remember changing a setup at a property some years ago, whereby a Kitchen sink with a Waste Disposal Unit, entered the stack directly opposite the waste from the Downstairs Cloakroom Hand basin, the basin was less frequently used and constantly blocked, to the point where they warned people not to use it after using the WC!

WC branch has a slight sweep on it, but given the volume of flow coming through when the WC is flushed, it will foul any opposing connection, as you've found out. If there is a reasonably accessible option to reroute the bath waste to a lower point for connection, I would do so, and cap off the existing.

 

[Flibblewibble]

Thanks both,
It is a new bathroom and stack so not even any room for excuses around having to fit with existing plumbing.
Will see where we get to with the installers but as you’ve both observed if you are willing to install like that in the first place then you aren’t a decent tradesperson so I expect it will be hard work.

 

[Madrab]

Yeah - the trouble you may have - when looking at the regs - is it could be argued that the bath waste does fall outside the zone created by the swept branch for the WM.
The one you could certainly use is paragraph 1.10 where it states that "A branch pipe should not discharge into a stack in a way which could cause crossflow into another branch". Obviously the way they have configured those connections, that's exactly what's happening. Just looking at it you can see that's exactly what would happen given the volume flowing from the WC .

You say it's a new bathroom, if so then that would normally be notifiable, if so then that really shouldn't have passed inspection.

 

[Hugh Jaleak]

Will see where we get to with the installers

Let us know the outcome please.