Damp meter

[Mark BR]

Looking at buying a new house (well old house but new to me) and thought using a damp meter before employing a survey could save time and money on an unsuitable house.

But are the meters at £12 or so suitable?

eg this one from ebay:

--

MarkBR

[Alan]

In message , Mark BR wrote

'surveyor' in his job title it tells you that you need to spend lots of money on rising damp treatment.

[NT]

ha

Theyre designed to indicate the water percentage in wood. Masonry is quite different, both chemically and physically.

What matters with masonry is not the water precentage, but signs of a damp problem. Blowing plaster, salt deposits, mould, rot.

Meters are used to convince people to give you their money, not because their readings are really relevant.

NT

[Andrew Gabriel]

probably be OK, although can't tell what it reads out, as there's no example image of it switched on.

The hold feature is important, because when used in difficult to get to dark corners, you often can't see the display (too dark or not facing you) whilst the unit is in position to do the test.

As NT indicated, they are OK for timber, but can be more difficult to interpret for masonary. In the case of plaster, how easily you can push the spikes in is often a more useful indication than the actual reading;-)

[Martin Brown]

> Will probably be OK, although can't tell what it reads out,

I actually prefer a relatively simple 555 timer circuit where the oscillator frequency is determined by the resistance of the wall. A couple of pins about an inch apart as the sensor. The thing howls when you stick it into seriously damp wall and makes a gentle ticking or no noise at all on dry wall. The pinpricks it leaves are barely visible.

Basically you want a quick go no-go indication of is there a problem wall here or not. Reading a meter in dark corners where the problems always seem to be hiding is too much of a faff.

[Mark BR]

*Theyre designed to indicate the water percentage in wood. Masonry is *quite different, both chemically and physically. * *What matters with masonry is not the water precentage, but signs of a *damp problem. Blowing plaster, salt deposits, mould, rot. * *Meters are used to convince people to give you their money, not *because their readings are really relevant. *

------------ So probably a waste of £12 - I can see damp in wall paper/paint etc on plaster.

Unless it is a house with lots of exterior woodwork - one house I am looking at has wooden windows so there it might be worth buying one.

Thanks for all

-- MarkBR

[Brian Gaff]

I don't think its so much the meter as knowing where to look for the damp if its not obvious.

Brian

[NT]

I cant see why

NT

[stuart noble]

Nor can I really. If you can easily push a bradawl into woodwork it's rotten. You need the prongs, you don't really need the electronics

[Andrew Gabriel]

With a damp meter, you can detect timber which is too moist before it goes rotten, and fix the cause of the problem. If you can easily push a bradawl into woodwork, it's already gone rotten, and you maybe too late to rescue it.

[Dave Liquorice]

But unless you repaint/varnish the two pin holes from the "damp meter" you have broken the integrity of the paint/varnish and thus it will fail sooner rather than later.

The only real use for a damp meter I can think of is checking the logs are dry enough before bunging them in the wood burner...

[NT]

But you can more easily detect that by looking. If the paint's sound, its ok, if the paint's not, it isnt.

NT