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What caused this paint failure?

We recently had our Victorian house painted for the first time in 10 to 15 years.

A few days after it was finished we noticed some slightly lighter and darker patches in some areas of the paint, but figured it was just the paint curing process going on.

Today it started raining and wow something is seriously wrong – see the attached pictures of the paint bubbling up.

What caused this paint failure?

Re: What caused this paint failure?


Did you wash the house before painting? It look like the wood was wet and cold when the paint was applied? What type of primer? What type of paint? Oil or Latex? I have only use oil based paint on my Victorian, and it has never done that. Will that scrape off? or is it hard? I can see a lot of dirt in the surface of the paint. Tell me that the surface was not prepared properly. Was that area sanded before being primed? If so, the dirt should have been blown off with compressed air. It is late in the year to be washing a house, it will not dry enough to prime and paint.


Handy Andy In Mt Airy NC

Re: What caused this paint failure?

The house was power-washed before painting - without detergent or bleach. It was allowed to dry thoroughly afterward. In our area the weather was perfect - light breeze, temps in the 60s - 70s, low humidity. 

Brand of paint is Benjamin Moore Regal Select exterior, freshly purchased from local dealer - I don't know the brand of primer. Note that the blistering is occuring in both primed and un-primed area. Latex paint. 

As the rain has continued, blisters have spread - there is no indication they line up with brush marks or other boundaries (like underlying primed vs. non-primed areas) - plus some blistering areas were sprayed, some brushed, and some roller brushed. No paint stripper was used.

Blisters are fairly soft and will scrape off with a fingernail. 

The dirt on the surface you see is from recent dust in the area (after painting was complete) that was washed off by the first rains we've had in a long time.

There was some sanding and scraping in some areas, and some filling with bondo, then priming - but the blistering doesn't show any pattern of matching particular areas that received different preparations. 

Mysterious, right?!

Re: What caused this paint failure?


If I didn't know the circumstances at all and just went by the appearances, I would guess that the paint was not sufficienty cured before the rain  or dew occurred. those low temp ratings stated on the paint cans, usually about 50 degrees, are for 24 hours after the paint job, not just at the moment of application. In most Northern areas of the country, November is not prime painting time.

In any event, it is definitely moisture related.

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