exterior painting

[shiznit76]

Hi, the paint on exterior of my house is flaking and almost powdery like as in photos. I had same issue just over a year ago and rubbed it back and painted the bare render, but it has happened again. How to i go about getting rid of this problem?

 

[misterhelpful]

You could have two issues there. The first being that water is getting into the narrow crack and therefore soaking the substrate which, as it dries out, causes the paint to flake. (The white powder could be efflorescence, if moisture is the cause.) Make sure the crack/s are filled and watertight before painting - it may be wise to apply a coat of alkali resitant primer when everything is dry, and after brushing off as much of the powder as possible, then start repainting.
If water penetration isn't an issue, the problem is likely to be that you just have a powdery/friable surface, so, in this case, you should apply a stabilising solution before you repaint.

 

[Robbie uk]

Yep, I'd go with the stabilising solution when its all been cleaned off and rubbed down.