Foul waste drop

[nottsrob184]

Hi all.
I am installing a downstairs toilet in the back of my garage...its planned to connect into the up stairs toilet waste pipe which drops down, so my new waste will connect at ground floor level to the existing but about 2.5mtrs away.
The question is....will i need to raise my new toilet to get a decent drop.
I envisage a 150mm height difference....is this enough to avoid blockage build up?.

Thanks

 

[RedHerring]

You should find all your answers in here:
http://www.planningportal.gov.uk/uploads/br/BR_PDF_ADH_2002.pdf

I think Table H1 gives a value of 18 - 90mm fall per metre.
So you're looking for 45 - 225mm fall along 2.5 metres.

Also bear in mind that you shouldn't join within 450mm of the bottom of the invert (the bottom of the underground pipe) Diagram 2.

 

[Nige F]

What shouldn`t be done and what is done are 2 different things . Like you should also notify Builing Control @ your local council

 

[noseall]

The accepted fall for foul drains is 25mm per metre (1:40).

However if using plastic, i know for a fact that these drains will continue to run with a lot less fall. Only trouble is you need to be very precise when laying them.