Discovered today that the waste from the bathroom washbasin is absolutely
full of clag - it's surprising it drained at all. Which isn't that
surprising as it is running absolutely horizontally for about 3 feet. The
sink is fitted with an S trap, from which the waste descends vertically, to
a 90 degree bend, from which it goes horizontally, ending in what I think is
called a conversion bend (90 degrees) which is pushed into some sort of
adaptor which is in turn fitted into the top of a cap on a vertical soil
pipe.

I went to a plumbers merchants thinking they'd be able to put me right - I
was thinking perhaps something like a pair of 92.5 degree bends would work -
but they'd never heard of them!!!!

Screwfix comes up with 92.5 degree bends and adjustable bends even - but one
of them needs to be a conversion bend to push into the top of a soil pipe.
Does such a thing as a 92.5 degree conversion bend exist?

Any thoughts?

TIA

Keith