DIYbanter - View Single Post - WC over-flows

Nightjar

On 04/12/2012 00:12, wrote:
Hi all,

Do modern WC systerns still need an external overflow pipe? I've been wondering for years why they don't just overflow down into the soil exit pipe and save boring extra holes through outside walls and whatnot. Now I have a Geberit wall frame unit to install and can't find any mention of overflow in the instructions, so I'm guessing maybe it doesn't need one due to this. Can anyone clarify the situation? I admit to being very out of date on this subject!

The Water Supply (Water Fittings) Regulations 1999 require them to be
fitted with a warning pipe or with a no less effective device. In other
words, if you don't have a pipe that discharges an overflow in a visible
place, you need an effective overflow alarm. Warning pipes are usually
cheaper. However, they do not need to discharge externally, so long as
the discharge is visible. Pipes are often lead into the back of the pan
where an external pipe would either be difficult to instal or be
unlikely to be noticed. Another method is to fit a tundish into the pipe
near the cistern, although you would need to fit a U-bend after the
tundish if you wanted to run it into the soil stack, to stop smells.

Colin Bignell