Stephen explained :
I was hoping to help by using one of those repair compression fittings
only I found I could not slide the nuts on. Do you think that the ice
stretched the pipe and made it fractionally wider? If so, what use are
these repair fittings?

The tap had a built in non return valve. I wondered whether these are
perhaps a bad thing? I realise there should be a valve but would it be
better fitted inside the house? If a tap was fitted without a valve
and the pipe was isolated and the tap opened, wouldn't the pipe drain
completely?

You could always fit the valve inboard of the point where it goes out
through the wall and inboard of an isolation valve. That way opening
the tap and turning the isolation to off should drain it.


Now if a tap with built in valve was used, would the pipe drain under
the same circumstances or does the non return valve require some
pressure to open it? Would water remain in the pipe that could freeze
and cause the damage that occurred?

I would have thought so (see above)

I am thinking of taking my sds drill and see if it will drill through
the concrete floor so that the pipe drop can be run inside the house
and go outdoors at the last minute.

I have a couple of taps outside and both only have the actual tap on
the outside, all pipework is inside. We have never had any problems
with freezing. There is a limit to how much lagging can help stop pipes
freezing. If it stays cold enough for long enough, eventually the cold
will get through and unless there is some heat source - the pipe will
freeze.

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Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk