General Info
Mildew is mold that can attack cellulose and lignin. It can ruin paper, cellulose fabrics, wood, paint, glue and leather. The mildew secretes an enzyme that decomposes organic matter and uses it for growth and reproduction. It is unsightly, produces an unpleasant odor and often acts as an allergen which can create health problems.
Mold and mildew grows from spores which exist almost everywhere. Certain conditions must exist for mildew to grow and reproduce.
- It thrives on organic materials such as leather, paper, and fabric. They serve as food sources.
- It requires moist, warm air. It grows best when the temperature is 77 to 86 degrees, however it can survive in temperatures from 32 to 95 degrees F.
- It can grow in dark areas and places where there is not much air circulation.
Since mildew spores are everywhere the best way to control its growth is to eliminate its food sources, deprive it of sufficient moisture and keep the temperature too low for fast growth. Keep things clean, dry, cool and have good air circulation. Don’t crowd clothes too tightly, have closets where air can circulate. Keep the bathroom, especially the shower, clean and dry. Reduce moisture when cooking and have good ventilation.
Prevention is the best way to control mildew. The severity of mildew will influence what must be done. If it is severe, ceilings and walls may have to be removed, the beams and other wooden structures re-sprayed with a mold/mildew retardant and new insulation and wallboard installed. Only your insurance agent and/or environmental engineer can tell about that. If the mildew infestation is not severe, Try the following suggestions.
Clothing
Begin as soon as mildew is discovered. Brush it off outdoors. Sun and air clothes before laundering or dry cleaning. To remove mildew stains that remain, try one of the following. Test fabrics for colorfastness first. Do not use chlorine bleach on silk, wool, or spandex fibers.
- Moisten the stain with a mixture of lemon juice and salt. Lay garment in the sun to bleach. Rinse thoroughly.
- Mix 1 to 2 tablespoons of powdered non-chlorine bleach containing sodium perborate or potassium monopersulfate with one pint of water. Use the water temperature recommended for the fabric or color. Sponge or soak the stain. Let stand 30 minutes or longer; then rinse well. Old stains may need to soak overnight.
- Mix 2 tablespoons of liquid chlorine bleach with 1 quart warm water. Sponge or soak stain for 5 to 15 minutes and then rinse.
Leather Goods
After testing for colorfastness, wipe leather with a cloth moistened with diluted alcohol* (1 cup denatured alcohol to 1 cup water). Dry where the air is circulating. If mildew remains, wash quickly with thick suds made from a mild soap or detergent, or saddle soap. Wipe with damp cloth and dry with air. Polish leather shoes, etc., with a good wax dressing.
After removing mildew, air or sun the leather product thoroughly.
Paper & Books
If books or paper are damp, dry in a breezy place. Take outside and brush off any loose mold with a clean, dry cloth. For damp wallpaper, heat or air condition the room to thoroughly dry plaster and paper.
Remove stains by wiping gently with a cloth that was soaked with suds and wrung out, and then rinse the stain with clear water. After removing the stain, pat the area dry with a soft, dry cloth. For stubborn stains, a chlorine bleach and water solution can be used. Rinse with clear water on a cloth and dry with a soft cloth as above. Try not to wet paper and do not scrub.
Spread pages of books fanwise to dry in an airy place. If still damp sprinkle cornstarch between the leaves to dry. Leave on several hours, then brush.
Upholstery, Mattresses & Rugs
Vacuum or dust off mildew. Be sure to dispose of vacuum bag, as it will contain mildew spores. Dry the item in the sun if possible. If mildew remains, sponge with a cloth moistened with 1 cup denatured or rubbing alcohol* mixed with 1 cup water. Dry thoroughly.
Rugs and carpets that show mildew should be shampooed and dried as quickly as possible. Sunning is a big help. Sometimes the cause of mildew on carpets is moisture from the floor or padding underneath. If this is the case, the carpet should be removed and the cause of the moisture determined and corrected.
Painted Surfaces
Inside
Scrub mildewed paint or plaster with a solution of ¾ cup household bleach to 1 gallon water. Rinse with clean water and allow to dry thoroughly before painting or papering. Size paper and use a wallpaper paste that is mildew resistant.
For Wooden* Furniture
Remove mildew with vacuum cleaner. Clean with a soft cloth dipped in a mild detergent and water solution, and wrung almost dry. Work with a small area at a time, rinsing with a cloth dipped in clean water and wrung almost dry. Dry each area thoroughly before going on to the next area. Mildew often feeds on the dirt and greasy film that accumulates on furniture. If a white film develops after this cleaning, wax buildup has probably occurred. Use furniture cleaner to remove the layers of wax. Finally, re-apply a thin coat of paste wax.
For Wooden* Walls
Scrub wood with a mixture of 4 to 6 tablespoons washing soda to 1 gallon of water. Do a small area at a time. Rinse with clear water and dry quickly. If mildew still appears, use a mixture of 4 to 6 tablespoons trisodium phosphate and 2 tablespoons household ammonia per gallon of water.
Be sure to test for colorfastness. Never mix ammonia and bleach. It produces a deadly gas.
Outside
Scrub mildewed paint with 2/3 cup trisodium phosphate,** 1/3 cup detergent, 1 quart household bleach, and 3 quarts warm water. When clean, rinse thoroughly with clear water. Then treat the surface with a commercial fungicide. Repaint with a mildew-resistant paint.
For a roof cleaner, use 2/3 cup of trisodium phosphate to 1/3 cup of detergent, 1 quart of chlorine bleach and 3 quarts of warm water. Work in small areas so scrubbing and rinsing can be done before the mixture dries. ***
When cleaning with chlorine bleach, use rubber gloves. Avoid contact with skin and eyes or prolonged breathing of the vapors.
Remember to protect plants from these chemical mixtures.
Unpainted Wood
Decks and Wood Shingles
Scrub surfaces with a solution of 1 quart bleach to 3 quarts of water. Rinse thoroughly. Commercial cleaners are also available. Read directions carefully to know what the cleaners will do, how to use them and what precautions should be taken.
Bathroom & Basement
Scrub surfaces with a solution made from 1 quart liquid chlorine (household) bleach, 2 tablespoons liquid detergent, 6 tablespoons trisodium phosphate**, and 9 quarts of water. Use a brush or old toothbrush to clean grout. Let surface dry, then rinse with plenty of water. If shower curtains can be washed by machine add chlorine bleach with the detergent. Use a warm water rinse for plastics and hang while warm for wrinkle to fall out.
* Water will damage wood if allowed to stay on it. Always test cleaner before using. Work with small areas that can be rinsed and dried before moving on.
** Trisodium phosphate is available in paint or hardware stores.
*** Chlorine bleach damages some roofing materials. Test before using.