plaster discolouration when painted

[watson789]

Hi All


i have recently had my kitchen re-plastered, i waited until the plaster dried then painted on some 1 coat matt paint, all good so far...

i put on 2 coats - just to make sure i covered it all as im not the most experienced painter! then about a week after it dried i started to see white marks coming through the newly painted walls. not too sure what the marks are and cant seem to find anyone that does. they are really patchy white marks around the window reveal and there are also another couple elsewhere on the walls.

anyone have any ideas what they are and how to get rid of them? im not sure wether its the plaster reacting withthe paint or just something to do with the paint!

have recently posted this on the decorating forum but no answers have come up so far so am hoping someone on here may know?

 

[Micilin]

Hi All


i have recently had my kitchen re-plastered, i waited until the plaster dried then painted on some 1 coat matt paint, all good so far...

i put on 2 coats - just to make sure i covered it all as im not the most experienced painter! then about a week after it dried i started to see white marks coming through the newly painted walls. not too sure what the marks are and cant seem to find anyone that does. they are really patchy white marks around the window reveal and there are also another couple elsewhere on the walls.

anyone have any ideas what they are and how to get rid of them? im not sure wether its the plaster reacting with the paint or just something to do with the paint!

have recently posted this on the decorating forum but no answers have come up so far so am hoping someone on here may know?

Do they look like splashes of something ? If so, it's PVA , I'm thinking , on a replaster job. They will sand off (should have been washed off while fresh).

Or are they white salts? Which would mean moisture coming thru

Hard to tel without seeng

.

 

[watson789]

i have painted the walls brown and its white showing through - it sounds like the salts now you mention it.

how do i get rid of it? what causes it?

 

[Alastairreid]

moisture/dampness.

 

[watson789]

so how do i get rid of the marks?

i have painted im guessing the walls will be sealed so will i need to sand back the paint and wait for it to dry out, or do i need to put something else on the walls to cure the salts showing?

sorry im a bit of an amature at this!

 

[Micilin]

First find out what is the cause - if it is moisture, and around the window reveal, is it water coming in around the frame or cill?

Where are the other patches?

Are the salts around the edge of the patch?

Before you replastered, were there any salts -or dark patches- on the old plaster, and if so do they correspond to thses new ones?

 

[roy c]

Are you sure that you waited till the plaster was fully dry? Some times when plaster is drying out (if a chemical dpc was injected) effloresence salts sometimes appear and you just brush them off till the plaster dries....Might not be the case but you never know!!!

You said you put one coat of paint on when dry, did you water this down for a "mist" coat?