Published on January 13th, 2013 | by Henri0
Dirt and mildew cause paint to peel
Q. My house was painted three and a half years ago. At that time, the paint was peeling badly. The walls were sanded, primed and painted with one coat. Now parts of the house are peeling as badly as before – some parts in very large areas.
The house was built in the 1950s and I do not know when it was painted last prior to my having bought it five years ago.
I would appreciate your opinion as to the cause of the peeling and whether it should have happened so soon.
A. The paint samples that you sent me show contamination from mildew and dirt on the back of the finish coat of paint. There are also some small chips of a darker yellow paint stuck to the newer coat – was this the previous color of the house?
Regardless, this tells me that the primer must be adhering to the bare wood where it was applied after sanding and that a considerable period of time must have elapsed between the priming and the application of the finish coat. This allowed airborne pollution and mildew spores to contaminate the surface, contamination that was not removed prior to the application of the final coat.
The house should be pressure-washed with a detergent solution by an experienced person to remove all loose paint and contamination. This should be followed by spraying the house with a solution of equal parts fresh Clorox bleach and water using a garden sprayer. Let the solution dry and apply a finish coat. Do not have the pressure washer use bleach while washing the house as the bleach does not stay on long enough to do its work; these two steps are best done separately.by