What Prep Needed Before Painting?

[rossj81]

There is one wall in my kitchen with patches of bubbled, flaking paint. It looks like damp, except it's too high and inconsistent for rising damp, there is no pipework above for possible leaks, and it's far away from the boiler, stove, and kettle so don't suspect condensation. It also hasn't deteriorated in the past three years since I bought the house.

Do you think it wants a basecoat/primer/sealant, or can I just scrape, sand, then paint? If I need a basecoat, what would you recommend?

Photo attached.

Thanks.

 

[Wayners]

Cold spot? Condensation forms on cold spot.
Hard to say so dig and look

 

[rossj81]

Possibly, but like I say, it hasn't got any worse in years so I don't think the cause is still there. I'm not keen to dig up the plasterboard unless I have to.

 

[sparkwright]

Could there have been some wallpaper paste residue left?

 

[rossj81]

Quite possibly. Other odd walls in the house were wallpapered, and just painted over the wallpaper without bothering to remove it first (I suspect by the estate agent).

It's entirely possible the kitchen wall was papered, in a poor condition, and the estate agent made a half-hearted attempt at removing the paper before painting over the residue.

Would that have this effect?

 

[sparkwright]

Quite possibly. Other odd walls in the house were wallpapered, and just painted over the wallpaper without bothering to remove it first (I suspect by the estate agent).

It's entirely possible the kitchen wall was papered, in a poor condition, and the estate agent made a half-hearted attempt at removing the paper before painting over the residue.

Would that have this effect?

When paint reacts with old wallpaper paste, it can look like that.

Other things can cause a similar effect as well.

 

[rossj81]

@sparkwright Finally got round to actually doing the wall today, and you were right. When I removed the light and plug covers, there were bits of old wallpaper stuck behind. Thanks for your help.