BillR wrote:

Nick Brooks wrote:

Hi all

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


Looks basically ok to me.
Check the charts on the Hepworth site as to what can be combined with what
at what slope.




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
sound.

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.