We have gutted our cottage as we are in the process of joining two
together. The new bathroom will be above the kitchen. We are planning
to fit a loo, sink, shower and bath in the bathroom and a sink and
dishwasher in the kitchen.
I'm planning to take the waste from the shower and sink together down
a 40mm pipe and the bath down another 40mm pipe. At what point can
they join the 110 waste from the loo before it goes underground?
what are the relevant building regs?
Does this look like a good plan?
sink shower loo bath
| | | | |
| | | | |
(_______(_______40mm_____| | |
| | |
| | |
| | | sink dishwasher
| | | __)________)
| | |
| | |40 mm
|_______________to underground waste
Try and keep the bath and shower waste together, because the difference in
height between the sink waste and shower tray waste will give problems of
flow back. Yep. The sink may empty into the shower, then flow away down
A think a better idea, is to make the outflow pipe a decent diameter (50mm)
to take all three appliances and try to keep the running level toward the
outside stack as steep as possible and with the shower tray at the highest
point, and if it's behind a deep inline trap (110mm running trap), it will
prevent the backflow from all the appliances.
The difference in waste outlet height between the appliances is your biggest
problem, but is easily overcome by either keeping them all separate, or by
putting the lowest to the floor at the highest point on the under floor
All good stuff. There are some regs to do with distances between joints
and minmimum and maximum falls on the pipework, but the basic layout is
You will need a vent pipe or durgo type air admittance valve somewhere
in the system.
Most halfway competent plumbers will know the rules, or ask a competent
architect to clue you in - or indeed ask the building inspector.
Your design seem fine as you are carrying out a one pip system. Jest make sure
you connect your 40mm bath waste to the lowest point in the branch.....then you
can run your 110mm for pan and use the outlet above the 110mm on the branch to
run your 32mm waste for basin. Doing this will help you from getting any back
flow as there are no cross connection if you get my drift. You can if you so
wish run any shower waste and simply connect to the 40mm bath waste. PLEASE
MAKE SURE YOU PUT IN ANY RODDIN EYES. DO NOT RUN WASTE INTO BASIN USING 90
DEGREE BENDS USE APPROPRIATE T AND INSERT RODDIN EYE JUST TO COVER ANY FUTURE
MAINTENANCE PROBLEMS. IF YOU REQUIRE ANY ASSISTANCE THEN E-MAIL ME ON
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