Paint on walls bubbling when wet

Hebrews12

***UPDATE***

I've sprayed the walls and and when it bubbles up, the paint just peels off really easily so I'll just have to do that with the whole wall and hope they're not all like that.  Underneath is a green paint (see picture).  Is it possible t tell whether this is lead or just a green paint from previously?  How would I know?  Thanks again.

mi-key

Hebrews12 said:

***UPDATE***

I've sprayed the walls and and when it bubbles up, the paint just peels off really easily so I'll just have to do that with the whole wall and hope they're not all like that.  Underneath is a green paint (see picture).  Is it possible t tell whether this is lead or just a green paint from previously?  How would I know?  Thanks again.

It will be paint, people didn't line the walls with lead. Lead is also a solid metal, and you can see the plaster through the green paint.

If it was lead, it would  be a dull grey colour, and if you scratched it it would be shiny silver underneath

JohnB47

mi-key said:

Hebrews12 said:

***UPDATE***

I've sprayed the walls and and when it bubbles up, the paint just peels off really easily so I'll just have to do that with the whole wall and hope they're not all like that.  Underneath is a green paint (see picture).  Is it possible t tell whether this is lead or just a green paint from previously?  How would I know?  Thanks again.

It will be paint, people didn't line the walls with lead. Lead is also a solid metal, and you can see the plaster through the green paint.

If it was lead, it would  be a dull grey colour, and if you scratched it it would be shiny silver underneath

I think the question is about lead based paint, not actual lead - a wall lined in lead would be wierd.

No idea how you could tell if it's lead based. Why do you ask- worried about releasing lead compounds while scraping off the top coat of paint?

stuart45

You can get testing kits. It's less common on wall paints, although some of the older distempers were said to contain white lead.

stuart45

It might have been painted over wallpaper paste, which when damped down has caused the paint to lose it's adhesion.

ashe

Could it be it wasn't originally mist coated? Our walls are like that and comes off in great clean chunks like picture 1 on OP's post. 

warwick2001

JohnB47 said:

mi-key said:

Hebrews12 said:

***UPDATE***

I've sprayed the walls and and when it bubbles up, the paint just peels off really easily so I'll just have to do that with the whole wall and hope they're not all like that.  Underneath is a green paint (see picture).  Is it possible t tell whether this is lead or just a green paint from previously?  How would I know?  Thanks again.

It will be paint, people didn't line the walls with lead. Lead is also a solid metal, and you can see the plaster through the green paint.

If it was lead, it would  be a dull grey colour, and if you scratched it it would be shiny silver underneath

I think the question is about lead based paint, not actual lead - a wall lined in lead would be wierd.

Maybe the previous occupant had a mini-nuclear reactor in the room? Or a full-body gamma detector? Lead would be a good shielding option.

UncleZen

Same thing happened to me. It turned out that about 1 sq meter of wall had not been prepped when new (just painted over new plaster), so I scraped of the bubbly paint until it was secure, primered the edge with some fancy zinser Primer specifically for the job, filled the step left by the paint and the unprepped wall, smoothed it, primered with normal Primer the unprepared patch and smothed edges, sanded painted. And it's not been a problem since.

Bigphil1474

OP, I get this in my kitchen because I painted it in a hurry and didn't prep the new plaster properly. I just slapped a couple of coats of emulsion on before the floor fitters came along. Every time the kitchen gets hot we get little bubbles mainly near the door and then they disappear when the kitchen cools. I would guess that the previous owner did a quick paint job before selling.

With my kitchen - I'll get round to it eventually. Yours probably needs scraping back and redoing properly.

ThisIsWeird

Hebrews12 said:

***UPDATE***

I've sprayed the walls and and when it bubbles up, the paint just peels off really easily so I'll just have to do that with the whole wall and hope they're not all like that.  Underneath is a green paint (see picture).  Is it possible t tell whether this is lead or just a green paint from previously?  How would I know?  Thanks again.

How old is the house, Heb? If you have any concerns about lead paint having been used, you can get quick and easy kits to test it. It's unlikely, tho', on walls - usually it's on the architrave and doors.

The good news is that the paint appears to be coming off easily with a water spray, so keep going. Once that's done, we can have a close look at that green wall below.

When dry, is it matt or have a slight sheen? (Look at it from a low angle to the light source).

If you wipe it with a damp cloth, what happens? Does it feel 'clean', or does the green coat soften and come off or become slimy, as it likely would do if paste?

What if you gently sand it with 120 grit paper - does it 'powder' easily? Come off? Leave a clean 'keyed' finish?