Damp Marks on Wall After Replastring and Painting and External Re-Pointing

[tomdaven25]

My first post on the site so bear with me...

15 months ago we had out walls re-plastered and painted.
We also had the external walls re-pointed.

At the time of the plastering being finished the weather was cold and heaters were used to dry the house out and then the central heating once it was fitted.

After about 6 months a rounded patch of what appears to be damp appeared.
There is also a few much smaller circles elsewhere in two of the bedrooms, with a slight yellow colour to them.

We used a damp proof seal on them and then repainted.

However they re-appeared a month later.

The largest one is in-line with the external-chimney.

The smaller patches are not in-line with the chimney, but on the same side of the house.

Any ideas or suggestions would be greatly appreciated..

[Bauwer]

My first post on the site so bear with me...

15 months ago we had out walls re-plastered and painted.
We also had the external walls re-pointed.

At the time of the plastering being finished the weather was cold and heaters were used to dry the house out and then the central heating once it was fitted.

After about 6 months a rounded patch of what appears to be damp appeared.
There is also a few much smaller circles elsewhere in two of the bedrooms, with a slight yellow colour to them.

We used a damp proof seal on them and then repainted.

However they re-appeared a month later.

The largest one is in-line with the external-chimney.

The smaller patches are not in-line with the chimney, but on the same side of the house.

Any ideas or suggestions would be greatly appreciated..

Could you please advise the built-up of your walls, eg solid stone wall or with a cavity, etc and the approximate time when your house was built? thanks