Mold is everywhere—mold spores are part of the air we breathe, and they’re just looking for a nice, moist, overlooked spot where they can take root and grow. Although mold growth and the health problems it causes are most concerning in the wake of large-scale disaster like Hurricane Harvey’s historic floods, it’s actually important to be aware of and control mold growth in any place that is wet or damp.
3 Tips for Preventing Indoor Mold Growth
1. Identify the source of any moisture problems. Mold needs moisture. Moisture that has collected on a porous surface is just the kind of growth medium that mold is looking for.
Common sources of moisture within buildings include:
- Leaks. Pipes can leak, or sinks or traps can overflow.
- Rain. Rainwater can find the cracks in roofs, overflow blocked gutters, seep around windows and other areas where seals are faulty, and be tracked in on people’s shoes, clothes, and umbrellas.
- Condensation. Where humidity is high and cool surfaces are available, condensation can contribute to mold problems.
- Rising damp. If a building’s damp course (layer of moisture-proof material laid in a building’s foundation or near the ground) is defective, or if there is no damp course, moisture can seep into the building from the ground.
2. Control excessive moisture and condensation. Repair leaks and overflows promptly, and take steps to control humidity and condensation. Strategies include:
- Use a humidity meter to check humidity in indoor areas. If indoor relative humidity is above 60%, take steps to bring it between 30% and 50%. When outdoor air is cool and dry, pulling more outside air into the building reduces indoor humidity. When outdoor air is warm and humid, a dehumidifier may be used to reduce humidity indoors.
- Insulate cool surfaces to prevent condensation. Condensation collects when warm air comes into contact with cool surfaces—like cool-water pipes. Insulating cooler surfaces can raise their temperature and prevent condensation. Increasing the air temperature indoors can also help to control condensation problems.
3. Remove any mold you find. You’ll need professional help to clean up any mold that covers an area of greater than 1 square meter or mold that is growing in areas contaminated by sewage or other fouled moisture. Building owners and maintenance or custodial workers can deal with smaller areas caused by clean water contamination (such as condensation or roof leaks) themselves.
Workers can safely remediate small areas of mold growth if they:
- Wear appropriate personal protective equipment, including an N-95 respirator, impermeable gloves, and eye protection. Be sure to select gloves that are appropriate for any cleaning chemicals workers may be exposed to. Goggles without ventilation holes are preferred for eye protection to keep mold spores out of workers’ eyes.
- Thoroughly clean nonporous materials, such as plastic, that are supporting mold growth.
- Discard porous materials, such as carpet and ceiling tile, that are contaminated with mold.
- Protect the building’s ventilation system from contamination with mold spores, either by turning it off during mold remediation or by sealing the area where remediation is taking place.
- Identify and control moisture sources so that mold will not recur. For places that are always damp, you may need to institute a frequent cleaning schedule.