Bath/Basin waste into horizontal soil pipe - is this possible?

[poopipepete]

Hi,

I'm in the process of adding an en-suite bathroom to my 1st floor flat. I have installed a horizontal (with correct fall) 110mm soil pipe from the external soil stack to the new en-suite. Pretty much directly where the soil pipe comes through the wall into the room, I have a WC feeding down into a 90deg bend attached to the end of the soil pipe. I also have a bath + basin 40mm waste feeding into the soil pipe just down stream of the 90deg bend through a boss-strap connection. This is into the side of the soil pipe.

Can anyone who is familiar with standard practice and building regs tell me if this is ok or not? I've had a look through H1/H2 but can't see anything that fits my situation.

I have drawn a pic to try and show the setup more clearly.

IMAG2282

• poopipepete
• 15 Feb 2017

Thanks in advance.

 

[Madrab]

Hmmm, not sure I'd be fitting a 40mm waste downstream of a toilet on the same soil pipe run, the 40mm outfall should really be at least above the water/flush level of the pan in case it backs up, or at least at the top of the soil pipe, last thing you want is sewage filling your bath or basin.

 

[durhamplumber]

I would be surprised if the toilet contents didnt reappear in your bath....or at least a nasty whiff!.

 

[Newboy]

Better to take the 40 mm waste through the wall and boss onto the vertical stack.

 

[poopipepete]

Thanks for the replies.

So I guess the risk is if the main soil pipe gets blocked, this could result in the toilet sewage going up the 40mm waste into bath?

Unfortunately having the waste connect upstream of the WC connection is not really possible as the top of the soil pipe is already at floorboard level (not really drawn correctly in the diagram), so I wouldn't be able to further extend the soil pipe and maintain the correct slope without going higher then floorboards.

Since I have already installed this I think I may see how it goes and if I get trouble I would have to route a separate waste pipe out to the stack. This won't be easy though which is why I didn't do this in the first place!