Our Victorian house was recently professionally painted – the job finished a few days ago. Last night it started raining, and this morning there are many places where the paint is now bubbling and blistering.
What could have caused this?
Note that:
- Power washing did occur – but plenty of time went by (multiple days), in a warm and dry climate, for that to dry before painting started.
- Some surfaces that are now bubbling were primed, others weren't.
- There hasn't been rain in a long time, so the wood of the house was thoroughly dry.
- The painters seemed to have been fairly careful about cleaning surfaces after preparing (scraping, filling, sanding) and before priming and painting.
- Conditions were pretty ideal during painting – dry, mild temps (60s to 70s), little to no wind.
Best Answer
I'm not an expert in the chemistry of paint so I did a little research and found this.
As the paint dries at different rates, it begins to pull and contract on one side, and stretch on the other, causing a bubble to form. The other way this can happen is if it rains on paint before it has dried completely.
Bubbles that occur on paint after it rains almost always happen very soon after the paint has been applied, and before it has had a chance to dry properly – often within the first 24 hours, although it could happen up to a week or more after the application.
Ref: https://www.homelogic.co.uk/exterior-paint-bubbling-after-rain-heres-what-to-do
Not sure if this helps but it seems to fit your description.