Stain Or Damp on Plaster

[Rolo]

Hi,

Had some skimming done, when it dried out I noticed what appeared to be a damp patch 7inch x 5inch, but when I touched it it seemed fine, just assumed it was something with the plaster.

Next thing I noticed was that during the heavy rain all around the patch became damp. I 'think' Ive fixed the problem with the leak, so tried drying the plaster with a hair dryer . The new damp patch dispeared, the original 7inch x 5inch remained but after alot of drying with hair drier it changed to the dry plaster colour. However 12hrs latter and no rain the 7inc x 5inch patch was there again but not expanding.

Will post pic tonight but question is, is it possible for a patch of plaster to be a darker colour and by heating it up change its colour, and then when it cools it goes back darker, for any other reason than it being damp ?

Is there anyway I can tell if is actually a damp patch other than just by touching it as I just cant tell. Cheers

 

[JohnD]

As well as the picture, tell us if it on on an outside wall or a chimney, and tell us what is on the other side of the wall (e.g. a cracked drainpipe; fixings for a hanging basket; garden tap; cracked brick, missing pointing; leaky gutter above, piled up flower bed above the DPC, whatever.

... I 'think' Ive fixed the problem with the leak..

tell us more about this leak.