In message , Jon
writes
Having done some plumbing work in my bathroom over the weekend, I'm now
faced with a problem of confidence... how long should I give it before I can
be confident that I can go to work and not come home to a house full of
water? The stuff I did was a mixture of soldered joints (everywhere I could)
and compression fittings

Once it's done it's done. IF a significant problem was going to occur
it'd have happened by now.

It's really the compression fittings I'm unsure of - the soldered joints all
seem fine, a couple of the compression ones dripped slightly after turning
back on which in one case was solved by tightening it up (!) and the other
by taking it apart and bunging more jointing compound in there.


It's quite common for compression joints to weep slightly - a slight
tightening is fine - it's better than over tightening to start with.
They shouldn't need any jointing compound at all - the joint is made my
the olive compressing against the pipe and the fitting. If it needed
jointing compound then it probably means the olive/pip/fitting was
damaged in someway. but if it's fine now then I'd leave it alone.

In a slightly separate issue, is it possible to use isolation valves to
reduce the flow of water to a fitting?

Yes, I guess they can, but it's not what they are meant for.

All the taps in my bathroom come off
the rising main which results in a large imbalance between hot and cold
pressures - fine for the sink mixer but I had some problems with the old
bath mixer. If I can't do this with the isolation valve, is there anything
else I can use for this?

Of course reducing flow rate is not the same as reducing pressure,
reducing the flow may work enough - no harm in trying I guess. But a
better option would be a pressure reducing valve. -you fit it in the
pipe and adjust it to suit - they aren't expensive.

Alternatively replace the taps with ones that are designed for use on
supplies with different pressures - they are not true 'mixers' as the
ones you have now are, but keep the hot and cold separate up to the exit
of the tap.
--
Chris French, Leeds