Can a newly painted wall cause high damp readings?

watermelonspring

This is a wall that had staining from previous damp issues and the damp stain was dry at the time of inspection. The plaster was repointed and the wall painted. 

A structural surveyor visited approx 10 days after painting and recorded:

1. High levels of damp/moisture measured in the wall
2.  No evidence of any damp or water ingress externally
3. External checks found no source of leak 
4. Damp could be due to recent painting

Is this plausible or could we be missing something big? Anything you would suggest?

greatcrested

Very likely.

Some constituent in the paint, most likely residual water but could be a chemical, salts etc, could cause an electrical connection between the two prongs of the surveyor's (so-called) damp meter.

(so-called because it measures electrical conductivity, not damp necessarily).

FreeBear

greatcrested said: (so-called) damp meter.

(so-called because it measures electrical conductivity, not damp necessarily).

And they can only be relied upon to give potentially accurate readings when used on untreated wood. Paints, preservatives, and so on, will affect the readings.

That said, in the right hands with a good dose of common sense, they can be used to give an indication of relative damp. Once a suspect area has been identified, a sample can be taken and inserted in to a carbide meter in order to get a quantitative reading.