Waste pipe for downstairs toilet

[paulg1]

Hi,

Hopefully this is the right forum section.

I'm looking to run a waste pipe from a new downstairs toilet into an existing downpipe from an upstairs toilet. The way I see it I have 2 options (see picture).



1. Route pipe along wall (with the proper fall) and round the corner into the downpipe near the ground. How would I do this? Would a strap on boss suffice?

2. Route pipe straight down into the underground drain. Would that cause any issues with letting gases escape up the soil stack? I imagine a strap on boss would be insufficient here since the join will be underground?

p.s. You will see some historical damp problems on the wall - hopefully that is now resolved by some rerouting of the guttering (out of shot)

Any comments would be appreciated.

Thanks,

 

[PrenticeBoyofDerry]

Are you talking about connecting the downstairs toilet waste/soil to an existing soil stack? As you should not be connection a soil waste to a drain pipe!

Their regulations concerning the connection of waste/soil to soil stacks, the lowest a connection can be made is 450mm from the sump of the stack.

http://www.planningportal.gov.uk/uploads/br/BR_PDF_ADH_2002.pdf

 

[paulg1]

Yes - the connection would be to an existing soil stack, not drain pipe.

 

[PrenticeBoyofDerry]

I have posted a link regarding the regulations on connecting waste/soil. I would recommend that you take a look at it before you proceed. It maybe that you will have to consider a stub stack.

 

[paulg1]

Thanks for that link - lots to think about.

So my understanding so far is that I can put in an unventilated stub stack and go via that into the underground drain.

However, page 7 implies that I can discharge a toilet directly into a drain so long as the depth from the floor to the invert of the drain is less that 1.3m (and it is in my case). Is there any benefit to the stub stack then? (other than rodding access) This connection will be for a toilet only - the basin is on another wall entirely.

(Just thinking through the options here - I'm not going to go ahead and do any of this tomorrow.)

 

[PrenticeBoyofDerry]

The stub stack will offer additionally ventilation and atmospheric pressure. This would be beneficially in preventing a vacuum within the pipework, when the existing toilet stack is being used.

 

[noseall]

Just run the waste on the green route into a mini access chamber. Don't bother with a stubby.
Include an access bend on the first turn down out of the wall.