S lo wrote:
Is it OK to reroute 3/4 of my roof's rain water down the foul water pipe
instead of down the surface water pipe?

My top floor flat has a dual water drainage system - FW and SW.
It has a double roof with a valley gutter between them, and two gutters at
the front and rear behind parapets.
Rain water from the centre valley and front gutters goes down drainpipes
inside my flat to the rear gutter and then it all goes through the parapet
down to ground at the back of the building.

The pipes are enclosed in massive plasterboard box sections running the
length of the flat and are not only taking up lots of space, but develop
leaks occasionally. When this happens, it's a real task to open them up,
repair the leaks and then replaster and paint them.

The SW pipe goes right next to the FW pipe at the centre valley, and
draining the SW from centre and front roof planes into the FW would mean I
could get rid of half of the pipe.

I know it's a mortal sin to connect FW to a SW drain, but how about the
other way around?
Cheers.


20+ years ago, you could apply for an "easement" to allow this on new
builds and alterations via building control. It wasn't automatically
allowed, but nor was it always rejected. I'm not sure what the
situation is now.

Andrew