Flaking and bubbling emulsion

[orchilnomad]

Decorating new house and on one wall there was some light flaking covering a couple of sq cm's. scraped it back to good paint and prob. took off 1/2 sq meter. Paint left seemed good, so sanded down and applied coat of emulsion. within half an hour there were bubles on the old paintwork, which I could then scrape off. this has now been repeated several times on the same wall. Plaster skim under the paint is good and sound, no damp etc. Can anyone advise best way to cure this? does it just need a coat of PVA?

Cheers

 

[Zampa]

Pinat doesnt flake/bubble for nothing...we need to get to the cause of it first because we can suggest a cure..

Is it an old house?
Is it near an extractor fan
Is it near a heat source?
What room is it in?
Very important question...was the old flaky paint powdery?

 

[gcol]

Very important question...was the old flaky paint powdery?

Zampa casts out.... will he reel in I wonder?

 

[orchilnomad]

House is 1950's, no extractor fan, no heat source, it's an upstairs bedroom, paint flaking is on the sloping exterior wall, under the roof. on the vertical exterior wall the paint is fine, also ok on the ceiling. Paint that is flaking is not powdery and at first appears sound. you can scrape off paint that is loose and get back to sound paint, then leave it for half an hour and go back to it and the paint that was sound now scrapes off. I've put a coat on some of the area has been scraped back to the plaster and this seems to be holding ok.

I guess worst case for me is that I just need to get that elbow grease going and scrape all the old paint off, but would like to know the cause and will I have the same problem next time I come to paint it?

Cheers

 

[Zampa]

Very important question...was the old flaky paint powdery?

Zampa casts out.... will he reel in I wonder?

Very difficult sussing the problem in these cases any chance of a pic?...given that its a fifties house you cant rule out distemperso..anyway lets think abut the cures..

Scrape off everything you can, what wont scrape off wash off..have you tried washing the defective stuff off?..does the sponge/water turn coloured?

Allow to dry and coat the whole area with alkali resisting primer..leave to dry thoroughly for a couple of days and then fill arounf the edges, then re-paint.

Hope it works..