Painting & Decorating

Paint or paper to cover damp patches?

Anonymous user 09/03/2024 - 2.46 PM

Hi, I have a damp patch at the top of my chimney breast. I have checked in the loft and cannot see any cause, it is dry in that area. I also had work to the chimney to ensure this was sealed (nothing coming down it). I want to decorate the wall now and wondered which product would be best to try and prevent any damp from coming through. It was suggested to use a primer/sealer prior to wall-papering so I applied this to the area, however there are two spots (about the size of a 20p) that have reappeared, as well as a strip along where the wall and ceiling meet. I have seen a product called Anderton 3-in-1 damp proof foil which I'd need to put on, and then lining paper on top. I've also seen paint products such as Polycell or Ronseal damp seal. Painting seems the easier option for me but I want to ensure that the patch doesn't come through. Which would work best? (I appreciate that generally the cause should be tackled, but I genuinely cannot see why this damp is coming through. It's not spreading, just stays in the same areas it's always been. The chimney was used by a previous owner for an old Rayburn, albeit a few years ago now, so not sure if there could be deposits lining the chimney that keep bleeding through?)