Removing Mildew From Wood
Unpainted wood
In damp, warm, poorly ventilated areas, surface mold
often develops on wooden parts of buildings. Since new,
unseasoned lumber is particularly susceptible to mildew,
avoid using it whenever possible.
Painted wood
Indoor wood surfaces covered with enamel or oil-resin
paint rarely mildew, unless conditions are very favorable
for mold growth. Softer paints on outdoor surfaces mildew
more readily. Molds feed on the oil and minerals in the
paint and cause a dirty-looking discoloration. They may
penetrate the paint film deeply, even to the underlying
wood.
Mildew-resistant paints in all colors for outdoor
wood surfaces are available at paint and hardware stores.
Manufacturers have formulated their products with
fungicides to help combat mildew attack.
PRECAUTION: Mildew-resistant paints should not be
used on window sills, playpens, beds, or toys because
these paints can be injurious if they reach the mouths of
small children.
If mildew grows on wood, use heat and increase the
air circulation to get wood as dry as possible. Badly
infected wood may need to be replaced, preferably with
wood that has been treated or that is naturally decay
resistant.
Thoroughly clean mildewed surfaces, woodwork, and
other wooden parts by scrubbing them with mild alkali,
such as washing soda or trisodium phosphate (8 to 10
tablespoons to a gallon of water), or with disinfectants.
Paint and grocery stores and janitors' supply houses
sell these products under various trade names. Rinse the
wood well with clear water, and allow the wood to dry
thoroughly.Then apply a mildew-resistant paint.
If the mold has grown under the paint or varnish,
remove all the paint or varnish from the stained areas.
Then scrub with a solution containing 8 to 10 tablespoons
of trisodium phosphate and 1 cup of household chlorine
bleach to a gallon of water. Stronger solutions can be
used if necessary. Wear rubber gloves.
If stain remains, apply oxalic acid (3 tablespoons to
1 pint of water). The acid is poisonous; handle carefully.
Finally, rinse the surface thoroughly with clear water.
Dry well before refinishing.