"David Hansen" wrote in message
...

I wouldn't want to do that. Connections should not be made to the
stack within 200mm of the centre point of a lavatory connection.
This is to avoid the possibility of the lavatory discharge blocking
or obstructing smaller waste pipes.

Instead make the connection at least 200mm above or below the
lavatory connection, using a suitable boss. Whether it is above or
below depends on your plumbing. The hole can be made with a suitable
hole cutter (into a plastic stack).

There are patent fittings to avoid this, but I suspect it would mean
dismantling the stack to insert one, which you may not want to do.


Thanks for that, sounds like the easiest thing is just to join the waste
with the basin in the bathroom which I am pull the water feeds from. The
amount of waste will be minimal as its only for washing hands so should be
fine