Is It Ok to Paint over Mildew?

Never paint over mildew—it will grow through new paint, which will make subsequent cleaning and maintenance even more difficult. Wash the affected surface with a mixture of household bleach and water—three parts water to one part bleach—or with a household cleanser designed to kill mildew.

Will painting over mildew kill it?

Paint over mold does not kill it. Mold-resistant paint only works to proactively prevent mold, NOT reactively kill mold. Kilz and Zinsser make primers that claim to kill mold, but you should still remove the mold before using either of these products. There are mold-inhibiting additives you can add to paint.

Do you have to remove mildew before painting?

Before painting, it's essential to remove all mold and mildew -- which are essentially the same -- from the surface you're going to paint. In most cases, removal isn't all that is necessary; you also have to kill the mold, or it can grow back.