Excess moisture in bathrooms: the #1 cause of mold
Bathrooms, of course, generate a good deal of moisture through showers and bathing. In fact, of all the rooms in your home, bathrooms are the most likely location for excess moisture to occur, and therefore become an “amplification site,” for black mold to grow and become a health hazard.
When particular areas in a home have suitable nutrient and moisture content that fosters mold overgrowth, this is called an amplification site.
Many molds found in the home, such as aspergillus or cladosporium (usually found in toilets and air ducts), are non-toxic. However, they are allergenic, and can trigger symptoms such as watery eyes, rashes and a sore/itchy throat.
But other molds, such as stachybotrys atra (a.k.a. black mold), are toxic and can cause reactions such as nausea, chronic coughing, rashes, fatigue and long-term headaches. In addition, for some people, toxic molds can cause infectious diseases, respiratory problems, hypersensitivity reactions, and organ toxicity.
Typical signs that a bathroom has excess moisture problems
- Condensation on windows, walls and/or ceilings
- Mold visible between ceramic tiles, on walls or ceiling or under toilet tank
- Bulging gypsum board or drywall
- Peeling paint or wallpaper
- Musty smell
Some typical causes of excess moisture in bathrooms
- Steam from hot baths and showers
- Inadequate ventilation: lack of, under used, or malfunctioning bathroom exhaust fan
- Dampness from wet mats, towels and hanging clothes to dry
- Exhaust fan duct not insulated — condensation forms inside duct
- Room temperature too low/poor heat distribution to bathroom
- Plumbing leaking behind walls
Some practical solutions
- Always turn on exhaust fan when showering or bathing
- Install a bathroom fan that exhausts air to the outside
- Allow exhaust fan to run for 15 minutes or longer after showering or bathing
- Squeegee or towel-dry surfaces in shower stall or bath enclosure after use
- Fix leaking plumbing
- Ensure adequate heat and ventilation in bathroom
- Caulk joins in shower stall, tub and around sink. Repair/replace/seal grout in tiled floors and walls
- Consult a professional contractor for replacement of moldy walls and ceilings
- Have insulated exhaust fan ducts properly installed
To help reduce excessive moisture in your bathroom, install a 4.5-litre (1 gallon) toilet—this size does not tend to “sweat” as they hold less water