Hi,
My apartment that I have lived in since it was built (now 18
months) has developed marks on the painted plaster board. I only
noticed these marks after about 15 months from when the apartment was
first built. The only way to describe them is that someone has put
there fingers in grease and created a speckled effect all over the
wall. It has only happened on the walls that are on outer walls but
these are not Westerly facing (apparently this wall is normally the
coldest and attracts moisture). I did have a picture frame on one of
these walls and after taking it off the back of it was covered in
mildue.

The apartment is under NHBC 10yr (not that it counts much) and
I’ve had the builders out but they have been unable to explain
it apart from lack of ventilation \ drying. They recommended treating
it with a stain block type substance and decorating but I'd rather
sort out what the problem is, any ideas?

James