Assess the underlying surface and any moisture source before repainting.
All decorating problems
Paint failure · H&C advice
Blistering paint
Bubbles form beneath the coating and may later crack or peel.
- Raised bubbles on walls, timber or exterior paint.
- Paint separating in patches after heat or damp weather.
Understand before treating
What might cause it?
Similar-looking defects can have different causes. Assessment comes before product choice.
Trapped moisture, heat during application or an unsuitable surface can contribute. The cause depends on where the blister breaks and the condition beneath it.
Preparation & next steps
How we approach it
Allow the surface to dry appropriately and remove failed areas safely.
Prepare and prime as required; apply a compatible coating within the manufacturer’s stated conditions.
A primer cannot fix a leak or persistent moisture. Blistering that keeps returning needs further investigation. Check current product technical data, safety instructions and compatibility; this guide is not a site diagnosis or a guaranteed repair specification.
The right system for the surface
Product selection matters
A suitable primer or sealer may be part of the preparation, but it cannot replace fixing the cause. Zinsser is one of the brands we use; the exact product depends on the surface, defect and intended finish.
Zinsser UK product guidanceOriginal H&C guidance. We are not approved, accredited or endorsed by Zinsser.
Local decorating help
Let’s look at the problem properly.
Share your postcode, the affected surface and what you’ve noticed. Preparation and repairs are assessed before a quote is agreed.