Paint flaking on external render

[danr86]

hi, my builder has painted the outside of my new extension - block work with a render. However the paint has started to bubble and peel very badly.
Any thoughts on what can be done to rectify it thanks.

 

[dcdec]

How long did he leave the render to dry before painting?

 

[danr86]

How long did he leave the render to dry before painting?

2-3 weeks - I queried this with him at the time as he used 3x the amount of Sandtex paint I expected him to use but he said it was ok.
A few weeks after that he used filler on top of the paintwork to get a smoother surface in places and then painted it pretty much straight away.

 

[dcdec]

Exterior render should have 2-3 months in good drying conditions. Your paint is flaking because moisture is trying to escape as part of the drying process of the render.

 

[danr86]

What's the best way to proceed?

Thanks

 

[dcdec]

Its hard to say as its not an irreversible problem. I'd leave it to flake and peel until next summer then scrape/brush off all damaged paint and re-paint. You may need to fill some areas which should be spot primed with thinned paint. Any rendered areas that arn't bonded well will also crack from the frost, these will need removing.
The builder has made a balls up of this so he should offer you a solution but i guess its up to you how you proceed. Good luck.