Back to Home Improvement

Best tips on how to clean mould and fungi

Black mold is it mold Zolo

It’s not fun but mould, or any form of fungi, doesn’t have to be the death of a real estate deal. Before ripping up the contract or shutting the door on an otherwise perfect property, take the time to find out whether or not the potential mould or mildew is simply a need for better home maintenance or a more serious and potentially expensive problem.

Moulds are part of a group of micro-organisms called fungi that also includes mushrooms and yeasts. This makes mould one of nature’s decomposers: destroying anything organic from food, to wood, to drywall, to carpet and other building materials.

If allowed to grow in your home mould could cause damage, sometimes significant damage either to your home’s structure or to your family’s health. 

Yet, just because you may notice mould in your house, doesn’t mean it’s a significant or expensive problem. To help, consider these tips on how to effectively clean mould and fungi around the house. 

Start with a Visual Inspection

When shopping for a home  — or when preparing a home to sell — it’s important to do a visual inspection to determine if mould is present. Look for signs of discolouration — when the fabric or other organic material (and this includes wood, cement and fabric) changes colour — which is a sign of mould.

Keep in mind, however, not all discolouration is due to mould. Carpeting near baseboards, for example, can be stained by outdoor pollution entering the home. Stains or soot may also be caused by the smoke from burning candles or cigarettes.

Also, don’t assume that black is the only colour to watch for. Moulds can grow in a variety of colours, including black, white, red, orange, yellow, blue or violet.

If you see and suspect mould, dab a drop of household bleach onto a suspected spot. If the stain loses its colour or disappears, it may be mould. If there is no change, it probably isn’t moulded.

Use Your Nose

Another good way to test if a substance is a mould is to perform a smell check. If a room or house smells musty or earthy, this is a good indication that mould is present. Also, look for wet spots, dampness or evidence of a water leak — all of which are indicators of moisture problems and this is the primary precursor for mould growth.

When to Clean Up Mould and When to Call a Professional?

Black mold is it mold Zolo
Malkin Cleaners / West Vancouver

In most cases, mould can be easily cleaned up using everyday household cleaners. Typically, mould clean-up is safe if the:

  1. Mould grows outside
  2. It’s a relatively small patch of mould (defined when the growth is fewer than three small patches that are each no bigger than one square metre each — about the size of three 4×8 sheets of plywood).

If the mould doesn’t meet these criteria, or if you suspect considerable mould growth in the property, or you’re not sure about the best course of action to take, then call for professional assistance.

Contact a trustworthy mould removal company to ask for an inspection. From there you can determine what type of removal service is required, if any. If you’re a seller or buyer, remember to budget between $250 to $1,000 for the inspection and analysis of the mould, depending on the size of the house and the number of air tests that are required.

When Mould is Safe to Self-Clean

Most homeowners will want to douse the mouldy area with bleach — Don’t! Despite local tales, bleach is not a reliable way to disinfect mouldy areas.

Instead, clean small area patches with two parts water, one part dish detergent. Wash the area and then quickly dry it (consider putting a fan on it as soon as it is washed).

Also, remember to protect you and your family when cleaning up mould, as almost every form of the fungi can irritate the respiratory system. Wear protective safety glasses (or goggles), rubber gloves, as well as a disposable dust mask.

If the small patches to be cleaned are inside the home, make sure infants and family members with asthma, allergies or compromised immune systems are not home during the cleaning process. Scrub all washable surfaces with an unscented detergent solution — typically two parts water, one part detergent, then dry the area quickly (you can rent high-powered, commercial-grade contractor fans for half-a-day to help dry spot-treated areas).

If the mould or mildew has turned into wood rot or it’s on drywall, then cleaning the fungi off is no longer an option. At this point, you’ll need to look at removing and replacing the areas affected and this typically means getting professional help.

Finally, keep in mind that once an area is cleaned (or contaminated material is replaced), the issue isn’t gone. You’ll need to solve the bigger issue: the moisture in the house.

Updates and Renovations to Prevent Mould

young couple stares at home reno plans

The key to addressing mould is to prevent mould growth and this is done by making sure a home is dry and well ventilated.

That means you will need to determine how and why moisture is entering and / or staying in your home. For instance, is one of your home constantly wetter because of excess condensation on uninsulated pipes? Or do you have an insufficient amount of insulation in your walls or attic, which leads to dramatic temperature changes and the potential for more internal condensation? Or does your roof lack the right number of roof vents, which help with the circulation of air circulation throughout the home?

Moisture can also be a result of water penetrating your home’s exterior structure, such as seeping up from the earth and into a basement floor, or a leaking interior wall pipe, or through holes in walls or roofs.

Turn your attention to what could be contributing to higher moisture levels in the home and then spend time and money fixing these issues. 

Keep it in Perspective

Don’t be alarmed if you do find mould or mildew in your home. According to a Harvard study, roughly 70% of homes in North America have some type of mould present in the home — despite a lack of smell or any visible infestation.

As the report author, Dr. Ronald Gots, explains: “It is highly unlikely that there is a home in the world without some Stachybotrys — black mould — spores in it.” For that reason, the prevention of mould growth, through home repair and continued maintenance, is the best defence against fungi.

Gots also points out:

  • Looking at symptoms alone is a poor means of evaluating disease, one fraught with the potential for error. It is an impossible way to draw causal connections, particularly when fear, publicity, and litigation are at work.
  • Fungi primarily produce allergies in people. These are standard upper respiratory allergies and occasional asthma. In rare cases, they may produce hypersensitivity pneumonia, although I know of no case from a home and only very rare cases from buildings. Also, fungi may rarely cause infection. Again, I know of no such cases from homes or buildings, except hospitals, where aspergillosis is a risk. Infections from indoor exposure to such moulds as Aspergillus can lead to infection in immunocompromised patients: transplant patients, cystic fibrotics, chemotherapy patients, other and related disorders. Even in these individuals, the risk is low.
  • The best-known mould infections occur from outdoor mould. Histoplasmosis in the Ohio Valley and coccidiomycosis in the San Joaquin Valley are the prime examples.
  • The mould at summer camps is much more extensive and, theoretically hazardous, than the mould found in a home, school, or workplace. Yet, no disease Aoutbreaks@ have ever been reported at a summer camp._ Occupational exposures to many moulds (including Stachybotrys) can be in the millions of spores/m3 and may affect people such as sawmill operators, landscapers and mushroom and horse farmers. These people have elevated incidences of allergic diseases.
Image of Romana King

Romana King

Romana King is an award-winning personal finance writer, real estate expert and the current Director of Content at Zolo Homebase. Romana has contributed to business and lifestyle publications including, Toronto Sun, Maclean’s, MoneySense, Globe & Mail Custom Content Team, and The Toronto Star. Among her achievements, Romana won silver for her annual Where to Buy Now real estate package in the 2019 Canadian Online Publishing Awards. In 2015, she won a SABEW Business Journalism award. When she was editor of CI Top Broker, Romana helped guide her team to obtain its first KRW Business Journalism nomination, and in 2011, she was part of a small team that helped MoneySense win Magazine of the Year at the 34th annual National Magazine Awards. Her north star is to consistently provide actionable, valuable and accurate information that helps elevate the financial literacy of everyone.