Stuart Noble wrote:
Tim Downie wrote:
I normally try not to put any fat down our sink and when I do, I
make sure I use plenty of detergent & hot water

Better to leave fat to cool and then bin it I would have thought.

Don't think I ever suggested to the contrary. ;-)

Oil
and detergent is ok though.
Oil or fat plus caustic soda equals soap with a greatly increased
volume and, being only slowly soluble, it can create more of a
blockage initially.

Can't see any chemical agent being any good on a pipe that size when
everything you chuck down the drain will flow through the hole at the
bottom. Although I've no intensions of chucking any quantities of fat down
the drains there's always likely to be *some* that goes down so I'd still be
interested in a domestic grease trap.

Tim