PLASTER WON'T DRY

[steveH]

About 6 weeks ago I had about 2 square meters of my kitchen wall replastered. The original layer of plaster was hacked off and the new layer applied was about 5mm thick. It has almost dryed out except for a patch about 50cm across, which is still a dark cement like colour. It does'nt seem to want to dry. This morning I put a hairdry onto one part of it and kept it there for about 3 minutes. It made no difference to the color. However, I was still sure it was related to water so I put a very hot electric iron up against the dark bit and to my surprise water trickled out from under the iron (not a steam iron :-) ). When I lifted the iron off after about 2 mins the plaster was almost white. I seemed to have got rid of a lot of water. Is there something wrong with the plastering or am I just being impatient?

[Rob graham]

I don't think you're being impatient. There must be some reason why there is still water in the wall. It must be getting in from somewhere. I would expect it to be normal pink colour within a week, depending.

Why did you have it replastered in the first place?

Was the plaster coming off?

Was it already permanently wet?.

Is it an outside or inside wall?

Rob Graham

[steveH]

It was coming off the wall or sounding hollow. Underneath it is another layer of plaster which appears to be fine, beneath this is an artexed wall. This is all in a kitchen where the roof had been very leaky for many months. The roof and the plastering were done at the same time.

No wet but very cold to the touch.

Outside wall.

[Rob graham]

It sounds as though the wall is 'full' of water and may take time to dry out, assuming that the roof is now OK. Possibly removing and replacing the plaster has caused a channel which ducts the water to one spot on the plaster, whereas before it spread over an area and was not so noticeable.

Just a theory, though.

Make sure the roof's definitely OK and wait until the weather has dried things out.

Rob

[mike]

Hi Rob, the iron was not a good idea as I have now got some very small cracks. They are'nt a big deal though. I have put an eelctric heater up against the wall to see what happens. Your theory might be right about the wall holding water. Since fixing the roof there has been a lot or rain at times which has not been acompanied by worsening of the damp patch so I doubt if more water is coming in.