We are thinking of re-arranging our bathroom layout which will mean moving the toilet onto another wall, this will mean the waste pipe being extended by about ten feet and also turning a corner. Will there be a problem if we do this, looking around other houses they seem to have the toilet next to the stack so the pipe work is as short as possible.
Paul
Paul,
You cannot run the stack around the bathroom. It requires a minimum "fall". You will probably have to dig up outside and extend the stack underground to the correctly position. and then rise up to the toilet position.
The pipe has to have a continuous fall on its way from the toilet. Which basically means either raising the toilet if you move it further from the stack, or lowering the location where it enters the stack.
Paul, you can run the branch pipe to the stack around the bathroom.
You require a minimum fall, over 10' with a 90deg this will be around 3" The 'approved' minimum is 9mm per m, up to a 6m straight run to the stack.
You won't have to dig up outside or extend the drain to meet the invert of a new stack as suggested above.
A branch discharge pipe should be fully accessible for clearing blockages, hence the preference for external pipework over boxed-in internal pipes. A bend in a branch should have as large a radius as possible.
A long vertical drop (>1.5m) from a wc should be avoided to prevent self-siphonage of the trap.
Unlikely he will get it unless he raises the floor where the wc is.
You put a branch in and short length. This is the norm.
Best do the job properly instead of ugly 110mm pipe, that is liable to get blocked, snaking all over the place. Cowboy boding methods should be avoided.
Yes, you may well have a problem, since there needs to be quite a fall on a soil pipe to ensure the turds get sped on their way.
This often mens the pipe needs to go down throughh the floor and join to the waste downpipe at a lower level.
Or use of a saniflo macerator pump, which cannot cope with anything solid that anyone may inadvertently drop down the loo.
The Natural Philosopher wrote
Let's just clear this up. This work will need to comply with the Building Regs and for a branch pipe of 110mm dia with one WC, the Regs require 18mm fall per metre run. So if the WC will be 3m away from the stack there will need to be min 54mm fall from the invert of the pan outlet to the invert of the branch connection on the stack pipe. If this can't be achieved it will be necessary to either raise the pan or lower the branch connection to the stack. Remember modern WC pans have horizontal outlets, which might help.
Peter
Thanks for the replies so far, The stack at the moment is cast iron so we intend to change it for plastic. so moving the inlet from the toilet lower will be no problem. So to clarify as long as there is a drop of 18mm fall per metre run of pipe there should be no problem, even with one 90 deg bend? the plan is to have all the pipework outside rather than boxed in internally.
Paul.
As others have noted the fall can be as low as 18mm / metre run, which is only just noticeable with the eye, the idea behind relatively the low gradients is that if the pipe is too steep the water can flow quicker than the turds, hence leaving them high and dry in the pipe.
Jon
I wonder if someone at the Building Research Establishment tested this before publishing the information on it. Perhaps there's a British Standard turd?
.andy
To email, substitute .nospam with .gl
Absolutely, and as updated by the 2002 edition of the regs. Not as my earlier outdated suggestion. (damm regs bible is getting old)
Sounds like the external branch and new plastic stack will go > Perhaps there's a British Standard turd?
There is, although it's been europeanised now. Annex F of BS EN 997. They also seem to believe sawdust is regularly expelled from pans.
with perhaps upwards of 40 million toilet systems in the UK, you can be rest assured that many tests will have been carried out over the years!
and yes their is a british standard turd, in the form of plasrerscene!, condoms and sanitary towels etc are also tested. Jon
Andy Hall formulated on Sunday :
There is a British Standard turd substitute (seriously).
Yes - and his/her name is [insert politician/other public or private figure/NG poster etc. of choice here] :-)
The bend will need an inspection cover in it to rod out if blocked. It is going to look crap on the outside with all this 110mm pipes snaking around the walls. It would ensure you vent over the eves to avoid any problems.
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