plasterboard fixings showing through plaster and paint

[jfcquinn]

We had a garage conversion completed with external wall covered with insulated plasterboard and skimmed. I left plaster to dry for 4 weeks until perfectly white. Dots were clearly showing from metal fixings used but only as faint darker spots so i started to paint. I've painted 3 coats of white emulsion and dots still showing. I'm reluctant to start with more expensive light coloured top coats!
Have these areas simply not dried?
Any advice would be appreciated!!
Many thanks!

spots from fixings

• jfcquinn
• 14 Nov 2014
• 1

Spots from insulated plasterboard fixings coming through 3 coats of paint.

 

[Alastairreid]

If they used nailable plugs the skim will be slightly heavier at those points and will take slightly longer to dry out.

 

[noseall]

Think moisture - cold metal - condensation.
Hey presto - shadowing.

It is common in moisture laden buildings for condensation to seek out and reveal things like rafter lines, dry-wall dabs, fixings etc. It's known as shadowing.

Once the heating is on and you are back to normal moisture wise, then things should settle down.

 

[jfcquinn]

Many thanks for the advice. Heating on and dehumidifier in!