Decorating advice

[busytorty]

Hi I’ve got a wall in a bedroom that looks dusty but it’s not. I’m not sure if it’s the type of paint that was used Valspar or what’s underneath but I can see areas that have been filled and where areas have been painted. It’s like something is bleeding through. The valspar paint isn’t new it’s been on the wall a couple of years but I now want to paint the wall again and unsure what to do so I don’t have the same issue again. Can anyone advise please

 

[Wayners]

How old is the house?
Modern walls like pasteboard or old 1900s lime plaster

 

[busytorty]

It was built in the late 1950s

 

[Wayners]

Cavity walls.
Do you think you have condensation problems?

 

[busytorty]

This is an internal wall and the roof was replaced about 8 years ago so don’t think it’s that

 

[aveatry]

I noticed something similar and it was matt paint due to its rough texture it collects anything in the air and in corners look dirty. I use satin everywhere and very slightly sand between coats and also the final coat with very fine mirka sheets. Leaves it really smooth to the touch.

 

[Wayners]

Sand over it it's a rough surface.
Apply one coat of gardz.
2 coats of valspar premium matt.

Will be smooth and hard wearing

 

[busytorty]

Thank you so much