In message , Dermot Carroll
writes
Hi,

I am installing a separate shower in an existing bathroom. As the waste pipe
from the bath passes the shower location before exiting through the wall, it
would be a simple matter to 'Tee' into this for the shower tray.

However I assume that the shower tray would then start filling with water
every time the bath was emptied due to the higher level of water in the
bath.

It's not necessarily the case, my (large) basin and bath share a common
outlet but the bath never fills when I pull the plug in the much higher
basin. My washroom and kitchen also share a common pipe and the kitchen
sink never fills from the washroom butler sink which about 2 or 3 feet
higher than the kitchen sink.

I guess there are a number of factors which might affect whether the
shower would fill or not, such as the relative lengths and drops of the
pipes between the bath and tee, shower and tee, and tee and outside
drop, and any vacuum generated by the down pipe. Of course if someone
pulls the bath plug and the pipe is blocked/frozen beyond the tee then
there's the potential for an almighty flood.


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bof at bof dot me dot uk