Tim W wrote:
I have a very long (15m), almost horizontal, external waste-pipe
used to drain a washing machine in a utility-room.
The flow down this pipe does not seem as fast as it used to be.
I'm wondering what the best method is to clear the pipe?
....
Incidentally, the pipe runs over someone else's roof,
so it is difficult to access directly.

In that case, perhaps ignore the "night bit" and do it in the day. Keep an
eye out of any leaks (in case there's a bad joint and the gunk is holding
it togther...) Wouldn't want nasty chemicals dropping on someone's roof
unexpectedly...

Yes, I had better watch out for that.
In fact, the neighbour put in the pipe -
the water used to run through a gutter on his roof.


--
Timothy Murphy
e-mail: gayleard /at/ eircom.net
tel: +353-86-2336090, +353-1-2842366
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland