The old paint s is allowing the gasses out but the new paint is too stretchy and impermeable to these gasses.
Cedar siding paint bubbles.
Test results from the forest products testing lab run by the usda for the forest service show that after 12 weeks of exposure to sunlight cedar siding has lost half of its ability to hold a film forming coating system like primer and paint.
Cutting out the blisters priming and repainting solves the problems in those areas but then new bubbles pop up nearby.
Paint was applied in direct sunlight on a hot surface which trapped solvent vapor as the paint dried too quickly.
Here are the do s and don ts of painting cedar siding.
The took off all of the paint layers down to the primer over the cedar siding.
The problem is many painting contractors do not approach painting cedar siding the right way.
It is most commonly seen on wood siding and trim.
The house was last painted 15 years ago without any.
If you do it right painting cedar siding can last for a long time.
These are mainly on the west side of the house but all sides now have at least a few.
Plus often the new color is darker than the original causing the siding to heat up in the sun reactivating the old layers.
Sanding priming and repainting as bubbles appear or strip off all the paint that s bubbling and start.
After four tries sometimes with and without repriming the result is the same.
Blistering paint is identified by small to medium sized bubbles or blisters under the paint film.
I mostly do restorative exteriors which is the complete removal of paint from the siding sand oil prime and two top coats of latex 100 acyrlic.
The paint that is bubbling is pulling all the underlying layers of paint right off the grooved cedar shingles.
Bubbling occurs then gasses or liquids try to escape and get blocked by the new paint.
Cedar siding can be one of the most resilient beautiful materials that you can put on your home.
The majority of the siding is western red cedar and because these homes are 50 years old the siding is from old growth.
Paint versus stain on cedar siding.
Now that he s done we have noticed a progressively growing number of paint bubbles blisters.