On Fri, 02 Jun 2006 13:54:55 +0100, TheScullster wrote:

"John Stumbles" wrote

Ahem! you say 22mm pipe, suggesting copper rather than steel. Now you
say concrete floors. Errr, it _is_ adequately protected where it's laid
in the concrete, isn't it?

Haven't had need to expose the gas, but the heating pipes are wrapped in
hession type stuff, laid in a sand filled channel and concreted over.

Hair felt

Does this constitute adequate protection?

No, unfortunately not. At least, not by current standards - I don't know
what was required in 1978 but if I came across an installation like
that now I'd have to label it At Risk since, for all I know, the last thou
of copper might be about to corrode through and spout a leak.

The pipework should be protected by suitable wrapping tape or by being
coated with a bituminous paint. At the time of your installation a
suitable tape would probably have been grease-filled cloth ('Denso' tape).
(In the current British Standard this is no longer allowed and PVC tape
should be used instead.)

Can you carefully expose a bit of the buried pipework to see if it's
properly wrapped?