Mold is an ongoing problem in existing buildings and can cause significantly poor indoor air quality affecting the occupants’ health. Mold isn’t always visible and can very well exist in ducts. It comes from outside but grows in areas where there is significant humidity or water damage such as roof and plumbing leaks, flooding etc. Mold produces microscopic cells called spores that spread through the air, forming new mold colonies when they find the right conditions.
Mold can exist in any building if a combination (right conditions) of the following is present:
- Fungal Spores, settling on the surface
- Temperature between 40-70 def F
- Nutrition source: wood is an obvious one, but this could even be cellulose based insulation.
- Moisture (Liquid or Relative Humidity above 70%)
Health Impacts: The impact of mold on your health is dependent on the type and quantity present and the sensitivity of the person exposed. Again, exposure isn’t limited to inhalation, these toxins can be absorbed through the skin and also be ingested. Common health impacts are allergic reactions, such as runny noses, itchy-watery eyes, coughing, sneezing, and throat irritation to chronic conditions such as sinusitis and asthma. Fungi also produce Volatile Organic Compounds (VOCs) during the process of degrading a substance, such as wood, to obtain nutrition. The “musty” characteristic is a sign of VOC contamination. Exposure to high levels of VOCs can cause irritation to mucous membranes, headaches, decreased attention span, difficulty in concentration, and dizziness. Some fungi can cause invasive diseases in individuals whose immune system is already compromised, for example seniors, children, those with AIDS or chemotherapy patients. Mold Stachybotrys chartarum, is a type of greenish-black mold, associated with severe health effects in some people.
For San Francisco Architects,
proper construction detailing, using insulated sheathing
below the veneer can be considered as a precautionary step. Building physics makes warm air migrate toward cold air and moisture to travel toward drier areas. Since warm air is able to hold more moisture, there is significant loss of moisture within the wall cavity, causing condensation on the inner surface of the wall where the temperature is lower. Using insulated sheathing on the exterior and interior wall, accurately cut around openings can control passage of both moisture and air. It can also help keep the temperature within the cavity above the dew point condensation level
, preventing moisture to form within the wall cavity.
Other operational and maintenance steps that can be followed are listed below:
1. Keep spaces clean and dry.
2. Fix problems such as roof leaks, leaking pipes or faucets.
3. Make sure all spaces are well ventilated and use fans in bathrooms and kitchens.
4. Humidity levels should be kept below 50% by using an air conditioner or dehumidifier.
5. Avoid carpeting in wet areas, such as kitchens, bathrooms and basements.
6. Fix any water problems immediately and clean or remove wet materials and furnishings.
7. Dry all surfaces and fix the problem or leak to prevent further damage.
8. Install a dehumidifier where there is high humidity.
9. Replace damaged parts, such as drywall and insulation.
11. Discard moldy materials that cannot be cleaned, such as carpet, drywall etc. in an environmentally sound manner.
12. Proper clothing and a face mask should be used by the person cleaning mold.
13. For larger areas or if you are allergic to mold, consider hiring a professional to clean and fix the cause of the problem.
14. Lastly, control moisture as much as possible.