Boss on a soil bend

[MortarThePoint]

I need to get a toilet pipe and shower waste (plus others but similar principle) out of a room without passing much below FFL. My only thought is to do something like the attached image. It doesn't feel ideal, but is it a no-no? The exit of the bend would then pass through the wall and to a bend 90 heading down.

 

I want to avoid joining the waste pipe the other side of the wall as that is outside and will increase the visual impact.

[markc]

Not ideal as “solids” could end up going back into the neck of the shower waste and cause a plug. Would definitely be better higher up before the bend

[Big Jimbo]

Personally, i wouldn't use that. I can even believe that is an approved fitting. Problem, waiting to happen.

[Conor]

Nope, nope nope. You could change the 90⁰ for a Tee (or a "Y" + 45⁰ bend), with a length of 110mm going to the right, then a boss connecting the shower waste. And a decent fall away. This is all assuming that the toilet is directly above and not dropping from a height.

[markc]

1 minute ago, Big Jimbo said:

Personally, i wouldn't use that. I can even believe that is an approved fitting. Problem, waiting to happen.

I’m thinking it’s a photoshop 

[MortarThePoint]

Pretty clear cut then

 

10 minutes ago, markc said:

Not ideal as “solids” could end up going back

 

3 minutes ago, Big Jimbo said:

Personally, i wouldn't use that

 

3 minutes ago, Conor said:

Nope, nope nope.

 

I had concerns too, is this better

[Crunchynut]

I agree with points made. You may also repeatedly suck the trap out of the shower waste with the two so close.

 

I don’t think your alternative is any better unfortunately. The Y branch is mentioned is the way to go.

Edited September 15, 2023 by Crunchynut

[MortarThePoint]

2 minutes ago, markc said:

I’m thinking it’s a photoshop 

No it is sold, eg on Amazon, and I can see how OK if waste pointed up

[Conor]

This is what I did in our old house. Please bear in mind this was my first ever attempt at home plumbing and a lot of it was correcting what the previous plumber did. But see what I mean re the Tee.

[MortarThePoint]

6 minutes ago, Conor said:

Nope, nope nope. You could change the 90⁰ for a Tee (or a "Y" + 45⁰ bend), with a length of 110mm going to the right, then a boss connecting the shower waste. And a decent fall away. This is all assuming that the toilet is directly above and not dropping from a height.

 

Are you thinking like one of these laid on it's back as shown here

[MortarThePoint]

2 minutes ago, Conor said:

But see what I mean re the Tee.

Cross post sorry, a good length of 110mm before the tee seems sensible. Not sure I can manage that though.

[MortarThePoint]

In terms of the whole room, here's what I am up against:

 

 

 

Room 2.7m x 2.5m

 

 

~60mm screed depth

[MortarThePoint]

7 hours ago, Conor said:

This is what I did in our old house. Please bear in mind this was my first ever attempt at home plumbing and a lot of it was correcting what the previous plumber did. But see what I mean re the Tee.

 

I might be able to do something a little similar passing the 50mm shower waste underneath the toilet 110mm and the having it change to 110mm for about 500mm before the  using a Y on its back. A challenge is that the Toilet pipe ends up centred about 225mm above HCF at the junction so with the about 2.0m of run that makes it 225mm + 2.0m * 18mm/m = 261mm. A bit more to allow fall between Y and the 90 bend exiting the room makes for 270mm. If screed is 60mm and if tile adds 10mm that would put the pan connection at 270 - (60 + 10) = 200mm above tile which is about 20mm too high for most toilets. Closer than I feared it might be though.

 

The bath pipe could offset vertically near to the boss so as to slop flow towards the bath. Can I be sure the boss wouldn't get blocked with poo?

 

 

Edited September 15, 2023 by MortarThePoint