On Thu, 16 Oct 2003 23:08:24 +0100, John Rumm
wrote:

Witchy wrote:

The only true test for damp and its cause is a series of core samples
which are then analysed chemically.


Surely the only true test for damp is to look for evidence, such as
peeling paint/lifting wallpaper, rotten skirting boards, distemper,
wet plasterwork, staining and all the other ones we had in this house.

What good does a core sample do other than to show that the soil might
be wet? It's not chemicals that cause damp, it's osmosis. We've got

I think the core sample refered to in not taken from the ground as such,
but a core sample from a wall - i.e. drill a hole and collect the
brick/plaster dust. You can then analyse that for moisture content. This
give a much better indication of the actual moisture content of the
whole wall thickness rather than just testing the surface for moisture
content (or testing your wallpaper for electrical conductivity as most
"damp proofing" companies would ;-).

By the time you've done all that work you could just as easily have
done the visual checks - I've not heard of 'hidden' damp before

would ungrammaticaly calls it!), a concentration of chlorine might
indicate treated tap water from a leaking pipe for example and so on. I
am sure someone who knows something about chemistry (i.e. not me!) could
give some better examples.

I can imagine chemical analysis being handy to perhaps discover a
particular form of dry or wet rot so suitable treatment can be
arranged, but even with that the visual evidence is there first.
Happily for us the one room we had that had been weevil infested could
be dealt with, according to the T**m*n*x bloke, by 'removing the
source of damp'

Now I know why they charge so much
--
cheers,

witchy/binarydinosaurs