Leaking windows or those prone to condensation can lead to mold problems on the windowsills. Black mold can leave a stain on the sill and cause a musty odor in your home. It also can be a health hazard, so always rid your windowsill of mold as soon as you notice it. If you don’t remove it promptly, it can spread and rot the wood of the sill, requiring it to be replaced.
Put on safety goggles, gloves and a dust mask. Removing mold can release dangerous spores into the air.
Cover the floor under the window with a plastic tarp and tape it in place. This should catch any falling mold spores near the window and keep them from resting in your carpet or other flooring.
Open the window to ventilate the area and give the mold spores the chance to fall outside instead of inside your home. Make sure it’s a sunny, dry day to help the wood dry faster.
Mix a solution of one part bleach and three parts warm water. Scrub the black mold off the windowsill with a nylon brush. Dip the brush in the bleach mixture often. Wipe away the scraped mold and excess water with a clean rag. Allow the windowsill to dry completely. Wipe off any remaining residue with a rag dampened with clean water, then allow the wood to dry before closing the window.
Sand away any leftover black mold stains with sandpaper, then vacuum the dust created by sanding. This option is best for unpainted windowsills; if you sand a painted windowsill, you must prime and paint it again to return it to its original look.
Untape the plastic tarp and fold it inward, then place it in a garbage bag for disposal.