How to fix paint bubbles on walls

There are several reasons why your painted walls may start to blister. Blistering is most common with oil-based, glossy or satin paints.

3 main causes of paint blistering

1. You've applied an oil-based or glossy paint to a damp wall 

Oil-based, glossy and satin paints are more or less impermeable. In this case, paint bubbles can appear as the moisture in the wall tries to escape and is prevented from doing so.

2. You've applied a water-based paint over an oil-based paint

Oil-based paints do not mix with water-based paints. Have you ever tried mixing oil and water? It's impossible! The liquids will instantly separate and the same goes with paint.

3. You've applied paint in warm conditions 

It is recommended to paint in temperatures of 15 to 25°C. Anything below 15°C and the paint will dry too slowly; anything above 25°C and the paint will dry too quickly meaning it won't adhere properly to the surface.

Dealing with minor paint bubbles

Leave the paint to dry completely according to the manufacturer's instructions so that it can finish blistering. You can then sand down any bubbles safe in the knowledge that bubbles won't appear elsewhere. Apply a thin coat of smoothing paint to even out the surface. Apply a primer before coating with another layer of paint. If you are applying a glossy or satin paint, you will have to repaint the entire surface as any patched-up areas will be clearly visible.

Fixing extreme paint blistering

This process will be long and tiresome but it's the only way to get a good end result! You'll have to start by sanding down the entire surface as far as you can. Once your surface is sanded, clean and dry, you can apply a universal primer. Then simply wait for this coat to dry before applying your paint.