On Aug 16, 9:58 pm, fred wrote:
In article , John Rumm
writesfred wrote:

I was trying to work out the objection for the strap on but I suppose it the
lack of a sweep meaning that passing fluids could go back up the branch.
Sounds pretty remote to me. I thought of that when doing mine (in an
enclosed location) and placed a step drop of about 150mm in the branch
just before the joint to the stack.

In England that is a building regs requirement, see page 8 onward:

http://www.planningportal.gov.uk/upl...F_ADH_2002.pdf

A good doc, now filed, thanks for that.

Yeah. I've been having a whinge elsewhere in this group about how the
equivalent website in Scotland only publishes a high level
platitudinous version of the building regs.

I suspect the o/p's pipe is the grey water pipe for his part of the block (if it
is a tenement) in which rain and non-foul waste is mixed (around here at
least).

Yep that's the case.