Keeping mold off redwood deck may require a periodic effort

How do I remove the greenish mold from a redwood deck which receives sun in the summer, but little in winter? After removing it, what will prevent recurrence? Joseph B. Parker Jr. Durham, N.C.

Mold or mildew forms in shady, damp locations. You almost never see it on a hot, dry spot.

Thoroughly scrape the boards to remove as much mold as possible. Then wash the deck using a solution of one cup of bleach, one-half cup of tri-sodium phospate, and a gallon of warm water. Rub the surface with a medium-to-stiff scrub brush. Allow the solution to stand for 15 minutes. Then thoroughly rinse with clear water. Repeat until the mold is gone.

After allowing the deck to dry completely, apply an oil-base, semitransparent wood stain. Use brush or roller to suit your fancy.

Future mold control requires periodic deck inspection. At the first sign of mold, give the spots a scrub with the same solution. Expect to apply a thin coat of the stain about once a year.

As noted in previous columns, our paint consultant is Donald R. Boysen, vice-president for sales, Frazee Paint & Wallcoverings, San Diego, Calif. As an expert in the field, in your behalf, he has bailed us out of many a paint problem. Thanks, Mr. Boysen, for continuing and significant help.