Dark Molds and Mildew, Cleaning and Removal
Expert Cleanup of Discoloring Molds on Hard Non-Porous Surfaces
Apr 20, 2009
Black and brown molds (BBMs) are usually harmless molds (filamentous fungi). However, their unaesthetic appearance takes a toll on rain gutters, soffits, sidewalks, driveways and bathrooms. Some ignore mold, for others, cleanup is the rule. Cleaning, clearing and removal of discoloring mold from hard (non-porous) surfaces is not too difficult and a professional job description follows.
Black Brown Mold Characteristics and Features
BBMs are similar to other molds. They have hyphae and produce spores. BBMs' hyphae and spores tend to be more resistant than hyaline non-pigmented molds. BBMs' melanin is their distinctive color. This pigment is deposited in hyphae and spores. Melanin protects these molds from sunlight since it screens out DNA-damaging ultraviolet (UV) light . Thus, BBMs can grow, in sunny and hot locations, and survive what would kill or harm other fungi. BBMs also embed in, and cling tightly to, their growth surfaces. This makes complete mold removal more difficult.
Action Plan and Strategic Cleanup of Black Brown Molds (BBMs)
The strategy for mold cleanup varies, depending on the location. Actions are listed, as professionals perform these tasks:
Basic needs for outside cleaning:
- clean scrubbing brush
- bucket with detergent, or disinfectant, for mold kill
- goggles for the eyes
- rubberized gloves for hands and boots or galoshes
- protective raincoat and waterproof cap
- pump spray dispenser (must be used only for the fungicide, labelled as such, and used for no other purpose)
- pressure washer is desirable. This must be used wisely and professionally to avoid pressure damage. Even professionals sometimes damage wood and concrete and other surfaces by improper use.
Some professionals prefer to use bleach; bleach works, but precautions are taken to prevent the oxidation and bleaching of non-targeted surfaces and human tissue; e.g. bleach tracked onto carpet or good clothing oxidizes and discolors. The quaternary ammonium compounds (quats) are useful alternatives, but they do not bleach out BBMs which must be scrubbed off or pressure-washed to remove the color. Mold disinfectant is applied to the surfaces for 10-30 minutes prior to wash or scrubbing. Quats leave an antifungal residue after cleaning and discourage mold growth. Rain ,snow, and dew dilute surface disinfectant over time. Paints with antifungal inhibitors are an alternative for mold-disfigured gutters that need repainting.
Cautions and Warnings for Professional Cleaners
- Make sure that the professionals never mix incompatible cleaners, either outside, or inside. Never mix powder cleaners with bleach. Never mix any two different brands or products. These produce dangerous byproducts and become inactive. Chemical reactions cause ammonia release and chlorine gas; both are toxic and noxious, and each causes lung and breathing distress. Every year hundreds of people go to emergency rooms with the bathroom cleaning syndrome for being ignorant of household chemistry 101 – One cleaner only! Never mix cleaners together in a bucket, or on the cleaning site. They react the same either way. Products are available for mold remediation and they are safe, when used according to the directions.
- Rubber gloves, protective goggles and waterproof coverings on feet, head and body are always in order when mixing or using fungicidal compounds.
- Pets should be protected from accidental or incidental contamination with cleaning solutions and equipment.
How to Clean Mold Off of Bathrooms Showers,Tubs, Tiles and Grout
This is the regular and routine indoor challenge.
- Ventilation during cleanup is required to prevent respiratory problems.
- Professionals should always mix disinfectants according to directions. It is recommended that directions be read twice. That's right – read them twice!
- Remember that professionals should use disinfectant spray first to kill as much mold before scrubbing. A good, tough long-handled scrub brush is useful. The reason to spray before brushing is to kill as many spores as possible.
- A bucket containing disinfectant is recommended to kill the spores and hyphae that are dislodged. Pieces of hyphae may reproduce the fungus. After scrubbing to remove embedded mold, the areas are sprayed again with disinfectant and mold is washed away.
- Keeping a bathtub or shower dry is useful for mold control.
Permanently mold-infiltrated grout (see photo below) should be replaced with grout that contains a mildew killing fungicide.
Regular and routine attention to the control of mold activity is required. Mold spores are spread easily by water, wind and physical-mechanical means. Mold spore control is very important.
Remember, molds can be removed and cleaned up. It is impossible to have a sterile environment, but regular attention and diligence will provide a clean and healthy home.
Sources
Campbell, N.A., L.G. Mitchell, and J.B. Reece. 2000. Biology, Concepts and Connections. Addison Wesley Longman, Inc. , San Francisco. 809pp
US Environmental Protection Agency website, 2009. "Mold Resources".
 |
 |
 |
 |
 |
