shadows of breeze blocks through paint

[sunnygal26]

Just after a bit of advice. My living room hasnt been decorated for about 4-5 years now but these shadows have recently started showing through. Could this just be the old paint or is it damp - im panicking because I wouldnt have the money to repair a lot of damp. The wall is backed onto an alley between mine and my neighbours house but cant see any broken brick work etc.

Any else seen this before?

thanks

 

[footprints]

I have seen it I doubt it is damp, just a difference in porosity between block and mortar, I would give it a couple of coats of stain blocker then repaint.
My go to blocker is Zinsser bulls eye 123.

 

[JohnD]

It can be pattern staining where the mortar is colder than the block, causing dust to cluster on it. The particles are very small, most often seen in rooms that are smoky from cigarettes or an open fire. It is extremely difficult to clean off, it tends to smear but a clean, dry soft white cloth will rub it partially off so you can see a difference.

Pattern staining used to be seen on uninsulated ceilings in older houses, between the joists.