It’s the houseguest you never want – and one of the toughest to send packing. Especially in damp climates, indoor mold is one of the most common and stubborn problems – and for people with allergies and asthma, breathing in those microscopic spores day in and day out can spell serious trouble.
Whether it’s lurking around window ledges, spreading under basement carpets or seeping through drywall under that leaky sink, it’s got to go. So how to tackle this growing problem?
Where’s The Wet?
There’s no point in trying to get rid of mold until you figure out where it’s getting its food. Mold can’t grow without water, so when you find it, the first thing you need to do is pinpoint the moisture source and stop it.
“The key to mold control is moisture control,” says Laureen Burton, a chemist and toxicologist with the Indoor Environments Division of the U.S. Environmental Protection Agency. “People think, ‘I don’t even need to look at where this came from because I’ve wiped it up.’ But if you don’t fix the moisture, that mold will be coming back.”
So where to start sleuthing? Chances are, there’s one of a few usual suspects at work: a leaky roof or siding, cracks in the home’s foundation, clogged or broken rain gutters, improperly sealed windows, inadequate insulation, a plumbing leak, a seeping washing machine or refrigerator, high indoor humidity or condensation.
Sometimes the source is easy to pinpoint, like a sweaty pipe under a kitchen sink, pooling water near a foundation or a beaten-up old skylight. Other times, you may smell mold but have no idea where it’s coming from; in those instances, you may need to call in the pros.
How To Clean Up
You’ve cut off the moisture source, put the mold on notice, and now it’s time for the clean-up. But how you do that depends entirely on where you find the mold and how much you have.
According to EPA guidelines, if the affected area is larger than 10 square feet (roughly three feet by three feet), or it was caused by sewage or other contaminated water, you’ll want to call in mold remediation professionals. (In Canada, the guidelines say to seek out the pros if the area of mold is larger than a 4×8-foot sheet of plywood.) But if it’s limited to a smaller area, or it’s on a hard surface, chances are you can tackle it yourself – so long as you follow a few key steps.
1. Out With The Mold
Many think that spritzing mold with a chlorine bleach solution will do the trick – but bleach can be problematic for people with asthma, and even dead mold can trigger reactions in those with allergies. Also, you could end up adding even more moisture to the area and actually promoting mold growth. Same goes with painting or caulking over it: it will only come back. So what’s the real solution?
Small amounts of mold on hard surfaces such as tile can be wiped off with basic detergent and water, or in more serious cases with a non-toxic mold cleaner, then carefully dried to prevent regrowth. You can do the same for more porous materials like drywall – so long as the mold is limited to the surface, and hasn’t made its way right through.
Once mold has set up shop in the nooks and crannies of carpets, ceiling tiles, drywall and other materials, there’s a good chance the affected areas will need to be scrapped – although steam cleaning and allowing fabrics to dry completely can save carpets and upholstery.
And if you think you only have a spot of mold near a baseboard, and then peel back a piece of wallpaper or wood paneling and see it’s coated in black, your DIY spirit should take a back seat and let the professional mold remediators take over.
2. Its Right Place
Molds love to set up shop in new locales. This is why it’s especially important that, during the clean-up process, you prevent them from traveling to other areas of the home where they can find moisture and get growing again.
For jobs that require more than wiping off, use tarps or plastic to seal the area so the tiny spores can’t spread. Also make sure that any nearby air ducts are sealed and that the heating or air conditioning systems are off; otherwise you run the risk of blasting spores into other rooms.
If you’re removing any moldy materials, just make sure to bag them up before you traipse them through the house; and once the affected area is dried out, give it the once-over with a HEPA vacuum, then discard the bag.
If you think you might have mold in your air system, spend a little extra and have your ducts cleaned.
3. Protect Yourself
Remember that mold can trigger symptoms even in people who don’t have allergies, so Dr. Ginger Chew, an epidemiologist with the U.S. Centers for Disease Control and Prevention, recommends that anyone doing the removal always protect themselves with an N95 mask, gloves and goggles. Those with allergies and asthma should avoid the affected area altogether – especially kids.
“It’s a case-by-case thing, but for a major rip-out of a moldy sink or cabinet, for example, I think allergic or asthmatic children should be as far away as possible,” she says. “And you’ll probably want to cover the furniture, because wherever the spores land, even if it’s dry at the time, given enough moisture and nutrients they could start growing there, too.”
4. Wash It Off
You’ve conquered the mold – but like any formidable opponent, it’s going to do its best to come back. That’s why it’s especially important that, when you’re finished, you wash the clothes you were wearing, and hop in a shower to send all those mold spores down the drain.
“Washing the mold spores from your hair is a good idea, because if you don’t, they can be transferred to your bed, or the sofa, or the child’s bed,” says Chew, who emphasizes that surfaces don’t need to be wet for mold to grow.
In fact, even a mattress with a tiny layer of moisture can be enough to kick start a new colony. “It can be just a thin layer of moisture that is invisible to the human eye. That’s one of the reasons that mold grows on walls, especially in climates where you have a big difference between the temperature inside and out,” she says.
Mold can reappear if the dampness isn’t quite completely eliminated, and sometimes when homes go from being improperly sealed to airtight, moisture can get trapped in unexpected areas. Burton recommends that, after any renovation or remediation, homeowners keep their eyes and noses peeled, and act quickly if they notice any signs of moisture or mold.
Still, she emphasizes that most often, the pesky fungi simply take full advantage of human neglect.
“Usually it comes from someone not dealing with the problem when it started. They had a leak, they patched it, put the wall back up and it was still leaking in behind. Or they had an issue and just painted over it.
“I can’t think of a story I’ve heard that didn’t start with a moisture problem that could have been controlled from the beginning,” Burton says. “The biggest thing is: once you find it, you fix it.”
First published in Allergic Living magazine. Subscribe here.