What to Know About Mold in Your Home

• If there has been a lot of water damage, and/or mold growth covers more than 10 square feet, consult with an InterNACHI inspector.
• If you choose to hire a contractor (or other professional service provider) to do the cleanup, make sure the contractor has experience cleaning up mold. Check references and ask the contractor to follow the recommendations of the EPA, the guidelines of the American Conference of Governmental Industrial Hygenists (ACGIH), or other guidelines from professional or government organizations.
• Do not run the HVAC system if you know or suspect that it is contaminated with mold. This could spread mold throughout the building.
• If the water and/or mold damage was caused by sewage or other contaminated water, then call in a professional who has experience cleaning and fixing buildings damaged by contaminated water.
• If you have health concerns, consult a health professional before starting cleanup.

Tips and techniques for cleaning mold 

The tips and techniques presented in this section will help you clean up your mold problem. Professional cleaners or remediators may use methods not covered here. Please note that mold may cause staining and cosmetic damage. It may not be possible to clean an item so that its original appearance is restored.   

• Fix plumbing leaks and other water problems as soon as possible. Dry all items completely.
• Scrub mold off hard surfaces with detergent and water, and dry completely.
• Absorbent or porous materials, such as ceiling tiles and carpet, may have to be thrown away if they become moldy. Mold can grow on or fill in the empty spaces and crevices of porous materials, so the mold may be difficult or impossible to remove completely.
• Avoid exposing yourself or others to mold.
• Do not paint or caulk moldy surfaces.
• Clean up the mold and dry the surfaces before painting. Paint applied over moldy surfaces is likely to peel.  If you are unsure about how to clean an item, or if the item is expensive or of sentimental value, you may wish to consult a specialist. Specialists in furniture repair and restoration, painting and art restoration and conservation, carpet and rug cleaning, water damage, and fire or water restoration are commonly listed in phone books. Be sure to ask for and check references. Look for specialists who are affiliated with professional organizations.

What to wear when cleaning moldy areas: 

• Avoid breathing in mold or mold spores.  In order to limit your exposure to airborne mold, you may want to wear an N-95 respirator, available at many hardware stores and from  companies that advertise on the Internet. (They cost about $12 to $25.)  Some N-95 respirators resemble a paper dust mask with a nozzle on the front, and others are made primarily of plastic or rubber and have removable cartridges that trap and prevent most of the mold spores from entering.  In order to be effective, the respirator or mask must fit properly, so carefully follow the instructions supplied with the respirator. Please note that the Occupational Safety and Health Administration (OSHA) requires that respirators fit properly (via fit testing) when used in an occupational setting.
• Wear gloves. Long gloves that extend to the middle of the forearm are recommended.  When working with water and a mild detergent, ordinary household rubber gloves may be used.  If you are using a disinfectant, a biocide such as chlorine bleach, or a strong cleaning solution, you should select gloves made from natural rubber, neoprene, nitrile, polyurethane or PVC.  Avoid touching mold or moldy items with your bare hands.
• Wear goggles. Goggles that do not have ventilation holes are recommended. Avoid getting mold or mold spores in your eyes.

How do I know when remediation or cleanup is finished? 

You must have completely fixed the water or moisture problem before the cleanup or remediation can be considered finished, based on the following guidelines:

• You should have completed the mold removal.  Visible mold and moldy odors should not be present. Please note that mold may cause staining and cosmetic damage.
• You should have revisited the site(s) shortly after cleanup, and it should show no signs of water damage or mold growth.
• People should have been able to occupy or re-occupy the area without health complaints or physical symptoms.
• Ultimately, this is a judgment call; there is no easy answer. If you have concerns or questions, be sure to ask your InterNACHI inspector during your next scheduled inspection.

Moisture and mold prevention and control tips: 

• Moisture control is the key to mold control, so when water leaks or spills occur indoors, ACT QUICKLY. If wet or damp materials or areas are dried within 24 to 48 hours after a leak or spill happens, in most cases, mold will not grow.
• Clean and repair roof gutters regularly.
• Make sure the ground slopes away from the building’s foundation so that water does not enter or collect around the foundation.
• Keep air-conditioning drip pans clean and the drain lines unobstructed and flowing properly.
• Keep indoor humidity low. If possible, keep indoor humidity below 60% relative humidity (ideally, between 30% to 50%). Relative humidity can be measured with a moisture or humidity meter, which is a small, inexpensive instrument (from $10 to $50) that is available at many hardware stores.
• If you see condensation or moisture collecting on windows, walls or pipes, ACT QUICKLY to dry the wet surface and reduce the moisture/water source. Condensation can be a sign of high humidity.

Actions that will help to reduce humidity: 

• Vent appliances that produce moisture, such as clothes dryers, stoves, and kerosene heaters, to the outdoors, where possible. (Combustion appliances, such as stoves and kerosene heaters, produce water vapor and will increase the humidity unless vented to the outside.)
• Use air conditioners and/or de-humidifiers when needed.
• Run the bathroom fan or open the window when showering. Use exhaust fans or open windows whenever cooking, running the dishwasher or dishwashing, etc.

Actions that will help prevent condensation: 

• Reduce the humidity (see above).
• Increase ventilation and air movement by opening doors and/or windows, when practical. Use fans as needed.
• Cover cold surfaces, such as cold water pipes, with insulation.
• Increase air temperature.

Testing or sampling for mold: 

Is sampling for mold needed? In most cases, if visible mold growth is present, sampling is unnecessary. Since no EPA or other federal limits have been set for mold or mold spores, sampling cannot be used to check a building’s compliance with federal mold standards. Surface sampling may be useful to determine if an area has been adequately cleaned or remediated. Sampling for mold should be conducted by professionals who have specific experience in designing mold sampling protocols, sampling methods, and interpreting results. Sample analysis should follow analytical methods recommended by the American Industrial Hygiene Association (AIHA), the American Conference of Governmental Industrial Hygienists (ACGIH), or other professional organizations.

According to the Texas Department of Licensing and Regulation (TDLR), “Mold assessment activities include an inspection, investigation, or survey of a dwelling or other structure to provide the owner or occupant with information regarding the presence, identification, or evaluation of mold, the development of a mold management plan or remediation protocol, and the collection or analysis of a mold sample. Mold remediation means the removal, cleaning, sanitizing, demolition, or other treatment, including preventive activities, of mold or mold-contaminated matter. The industry is regulated to ensure that persons conducting mold assessment and remediation services in Texas are properly trained and licensed, and are following minimum standards that protect the health of workers and building occupants.”

Suspicion of hidden mold: 

You may suspect hidden mold if a building smells moldy but you cannot see the source, or if you know there has been water damage and residents are reporting health problems. Mold may be hidden in places such as the backside of dry wall, wallpaper or paneling, the top-side of ceiling tiles, or the underside of carpets and pads, etc. Other possible locations of hidden mold include areas inside walls around pipes (with leaking or condensing pipes), the surface of walls behind furniture (where condensation forms), inside ductwork, and in roof materials above ceiling tiles (due to roof leaks or insufficient insulation).

Investigating hidden mold problems: 

Investigating hidden mold problems may be difficult and will require caution when the investigation involves disturbing potential sites of mold growth. For example, removal of wallpaper can lead to a massive release of spores if there is mold growing on the underside of the paper. If you believe that you may have a hidden mold problem, consider hiring an experienced professional.

Cleanup and biocides: 

Biocides are substances that can destroy living organisms. The use of a chemical or biocide that kills organisms such as mold (chlorine bleach, for example) is not recommended as a routine practice during mold cleanup. There may be instances, however, when professional judgment may indicate its use (for example, when immune-compromised individuals are present). In most cases, it is not possible or desirable to sterilize an area; a background level of mold spores will remain, and these spores will not grow if the moisture problem has been resolved. If you choose to use disinfectants or biocides, always ventilate the area and exhaust the air to the outdoors. Never mix chlorine bleach with other cleaning solutions or detergents that contain ammonia because toxic fumes could be produced. Please note: Dead mold may still cause allergic reactions in some people, so it is not enough to simply kill the mold; it must also be removed.

SUMMARY: 10 things to know about mold