Mike Deblis wrote:
How can you (non-destructively) test double glazing to see if it had
"popped" (lost its vacuum) without having to look for moisture inside etc.

They are not evacuated units - they may be filled with
special gas, though.


We have some 10-year-old thinnish (maybe 14mm) double glazing that seems
very cold to the touch and is getting condensation on (not in) it. One or
two of the panes have definitely gone (they have condensation inside the
unit), but if I'm going to have those replaced, I'd like to do any that are
failing too...

If they're not steamed up, they're OK. 464 units which you
seem to have aren't very good insulators anyway.

I don't know of any way to test the soundness of the units.