Mildew Check® Multi-Purpose Wash
This information is from
www.PPG.com
http://www.ppg.com/ppgaf/pline498.htm (bottom of page)
I have used this product with sucess under houses with mold growth.
"Mildew is not caused by paint.
Mildew is one of the most common and persistent causes of house paint failure. Mildew is a mold that grows on many types of surfaces. The most important contributing growth factor of mildew is moisture. It’s usually found in damp, dark areas; however, mildew is airborne and can grow anywhere.
Mildew is not caused by paint and mildew resistant paints are only as effective as the surface preparation done prior to painting. Mildew must be removed before painting or the mildew will grow right through the paint film. Since mildew looks like dirt, first verify to see if mildew is actually present.
Testing for Mildew: Where mildew is suspected, drop a little household bleach on the surface. If the soiled area, the bleach will whiten it; if it’s dirt, nothing happens.
Preparing the Surface:
Mildew Check® Multi-Purpose Wash is recommended for cleaning surfaces, both bare and painted, containing mold, mildew, algae and dirt. It will leave a protective water-insoluble residue to prevent mildew and algae regrowth at least twice as long as bleach and water solutions.
Mildew Check can be used effectively on wood, aluminum, vinyl, metal siding, and masonry surfaces Pre-test on a small, hidden area for color fastness. Typically, no re-painting needs to be done after cleaning with Mildew Check. Any additional questions, please call our Technical Services group at 1-800-441-9695."