Time to Repaint the Bathroom
TOH painter Mauro Henrique gives a homeowner his tips for painting a bathroom to keep it mold- and mildew-free
We have a problem in our master bath with mildew, even though we run the exhaust fan when showering and open a window in good weather. What specific kinds of paints or paint additives will retard its growth?
—Kate Dillman, Bay Village, OH
Shown: TOH painter Mauro Henrique rolls on a fresh coat of antimicrobial paint in a mildew-plagued bathroom.
Many paints and primers these days contain biocides that inhibit mold and mildew. Generally speaking, paints labeled for use in bathrooms will contain more of those biocides than average interior paint. You can get a pretty good sense of which ones actually do a good job of stopping mold growth by going online, to a site such as consumerreports.org. Or you can add a mildewcide, such as M-1 Advanced Mildew Treatment (Sunnyside), to a can of your preferred paint.
Before applying that paint, you have to get rid of the residual mold on your walls and ceiling. Otherwise, it could grow back through the fresh coat. This is not a job for chlorine bleach (sodium hypochlorite), which isn’t effective on porous surfaces. Instead, dissolve powdered oxygen bleach (sodium percarbonate) in hot water. Dampen the surfaces with water, wipe or spray on the oxygen bleach solution, and let it sit for 15 minutes. Don’t let it dry. Then wipe down everything with a clean, damp sponge. When the ceiling and walls are dry, you can start painting.
To prevent any mold that survived the cleaning from regrowing, apply an antifungal coating such as Zinsser’s Mold Killing Primer (Rustoleum). Cover it with two coats of bathroom paint. I suggest using an eggshell sheen, which is harder and more scrubbable than flatter sheens.
To keep mold off your new paint, you’ll need to aggressively ventilate the bathroom after each shower. Leave your exhaust fan running for a good half hour to clear out the moisture that these fungi need to thrive.