How to fix bubbled paint on exterior walls?

Marek51

Hi, several years ago I had my house painted - exterior.  I noticed some areas of the paint had bubbled.  The painters returned to 'fix' it, but bubbles returned.  I'm considering having a go at fixing them myself as most aren't too high.  Any advice on a) what the problem could have been, and b) how to repair so bubbles don't reappear?  Thanks in advance.  Maree

MitchellMc

Welcome to the Bunnings Workshop community @Marek51. It's fabulous to have you join us, and many thanks for your question about fixing a painted surface.

We’ll probably need a few more details before giving you a clear solution, as the cause can vary. Could you let us know whether your home is brick, render or weatherboard, and whether there are any existing moisture issues in the wall? One of the reasons exterior paint bubbles or delaminates is moisture sitting behind the paint film, which forces it away from the wall. Inadequate preparation is also a common cause. There’s usually an underlying issue, as paint doesn’t tend to bubble on its own. One way to check is to carefully cut into a bubble and see whether it’s damp behind it. Another possibility is that the paint wasn’t bonding properly in the first place, often because the surface wasn’t primed or prepared correctly.

If you can share a few photos of the problem areas, and perhaps what you find once you open up a bubble, it will help narrow down the cause and best repair method. Let me know if you need a hand uploading images.

As for repairing bubbled or peeling paint, the general approach is to scrape or sand the affected area to remove all loose or delaminated paint until you reach a firm edge, ensure the surface is clean and dry, apply an appropriate primer for the substrate, and then repaint with quality exterior paint while feathering the new paint into the existing finish. That will give you a long-lasting repair, provided the underlying issue, whether moisture or poor adhesion, is resolved first.

Please let me know if you have any questions.

Mitchell