Mention the word “mold,” and you can send a buyer running from a transaction. Agents need to understand the true nature of mold and its impacts to protect both buyers and sellers. The good news is that it’s an issue that can be fixed.

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Mold. The four-letter word that can kill a real estate deal. As a result, a culture of fear has developed around the word. Buyers bolt at the mere mention of it, while remediation specialists publish articles on the danger and devastation mold can cause.

It’s gotten so bad that in some states, home inspectors are advised to no longer use the word mold, instead they are told to use the term “fungal growth.”

But it all mold really that bad? No. Here’s what you need to know to help your clients negotiate that fuzzy world of fungus.

Fact No. 1: A mold is a mold but not a mold

The writer Gertrude Stein once wrote a poem stating that a “Rose is a rose is a rose.” The meaning was that things are what they are. But when it comes to mold it’s just not that simple.

There are more than 10,000 species of mold living in North American homes, according to CDC estimates (more if you expand the search globally.) Molds that grow inside an enclosed space, such as a house, are different than mold that grows outdoors. Even more astounding is that a mold that grows on wood may not be a mold that can grow on fabric. That’s because each species of mold likes a certain set of conditions to grow.

What does all this mean? It means that just because mold or mildew may be visually present in a home that doesn’t mean that it’s a bad kind of mold — you know, like Stackybotrys chartarum, otherwise known as black mold, which grabbed headlines a few years ago because of the harmful effects it had on people’s health.

It turns out that most molds belong to one of the following five types:

1. Alternaria grows on walls, in showers, around windows, under sinks and in various other damp places. It is often found in buildings that have suffered some kind of water damage. Alternaria mold can appear black, grey or dark brown and has a wooly or down-like texture.

What you and your clients need to know: Prolonged exposure to this kind of fungi can cause allergic reactions and asthma attacks.

2. Aspergillus is the most common type of mold found indoors. It can look grey, brown, yellow, green, white or black. Aspergillus mold usually grows on walls, insulation, paper products and clothing.

What you and your clients need to know: It can cause allergic reactions and respiratory infections, as well as inflammation of the lungs in people with weak immune systems

3. Cladosporium can grow in cool areas (unlike many other molds). It usually appears on fabrics, such as carpets or curtains, and on wood surfaces, like cabinets and floorboards. It has a characteristic black, grey or olive-green color.

What you and your clients need to know: It can cause a variety of respiratory problems.

4. Penicillium can be found on various materials that have been in contact with water, including carpeting, wallpaper, insulation and mattresses. It looks blue or green and produces strong musty odors.

What you and your clients need to know: Penicillium spores spread very easily and often result in allergic reactions.

5. Stachybotrys chartarum, often referred to as “black mold” because of its color, is the most dangerous kind of household mold. The toxic black mold has a characteristic musty odor and usually grows in areas that are constantly damp — around leaky pipes, inside air conditioning ducts where there is a lot of condensation, etc.

What you and your clients need to know: It produces toxic compounds called mycotoxins that can cause severe health problems, such as allergic symptoms, breathing problems, asthma attacks, chronic sinus infections, fatigue and depression.

Fact No. 2: Many, many homes have mold

Would it surprise you to know that, according to a Harvard study, roughly 50 percent of homes in North America have some type of mold present in the home — despite a lack of smell or any visible infestation.

Molds are part of a group of micro-organisms called fungi that also includes mushrooms and yeasts. This makes mold 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, mold can cause significant damage to your home’s structure by disintegrating less stable products, such as drywall and rotting wooden beams and posts. Mold will also stain and discolor fabrics, such as carpet and will ruin personal belongings. 

Getting rid of mold doesn’t have to be significant or expensive problem. For instance, fuzzy mold growing on an external window sill shouldn’t cause concern. These mold patches are common and should be considered a part of a homeowner’s responsibility for routine cleaning and maintenance on a house.

Fact No. 3: As a real estate professional you have an obligation

At the outset, you should understand three key points about mold liability:

  • As a real estate professional, you don’t need to become an expert on mold.
  • Large legal settlements don’t change what you’re responsible for disclosing.
  • Some basic and simple strategies can equip you to address this important issue.

To reduce liability, consider the following points. During your visual inspections:

  • Pay specific attention to stains or discoloration on ceilings and walls, including the baseboard area. Big mold problems start with small red flags. Learn to pick up the red flags associated with plumbing leaks and drainage problems to be on top of potential mold problems.
  • Pay attention to mold or mildew odors.
  • If you notice any of these signs of potential mold problems, talk to your client. Be sure not to offer expert analysis. Avoid using terms such as “black mold” or “toxic mold.” Generic descriptions such as “mold type” or “mildew-like” might be used. Here’s an example: “Some staining observed on the north wall of the basement den. Mildew-like odors also noted in master bedroom closet.”
  • Suggest (insist!) that your client pay for a qualified specialist inspection, such as a detection and lab analysis from a certified industrial hygienist (CIH) or other environmental specialist.
  • Avoid recommending a particular vendor. Instead, give your clients a list of vendors or simply direct them to the type of service they need and let them choose one themselves.
  • Consult your brokerage’s in-house lawyer to determine whether a special mold disclosure disclaimer form should be developed and signed by the transaction principals.

Address the bigger picture

For mold to grow, the following conditions must be met:

  • Temperatures range between 2 degrees Celsius to 40 degrees Celsius
  • There must be a food supply (which means anything organic such as books, carpets, clothing, wood, drywall, etc.)
  • There must be a source of moisture

What does this mean? It means your client needs to consider how to control the moisture in the home.

Moisture in a home can result from many issues: from excessive condensation on uninsulated pipes; a lack of insulation in the walls; and a lack of vents in the roof, which restricts the 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.

Regardless of how water is entering a home, consider it a sign of weakness; a failure in some aspect of the home’s structure. Rather than fret about the mold, tell your client to turn their attention to what could be contributing to higher moisture levels in the home. They’ll want to get an idea as to whether or not this is a big problem — such as cracked foundation — or a minor issue.

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

If you’re working with a seller, consider asking them to:

  • Actively work at keeping the home dry during the listing period.
  • Find, and fix water leaks.
  • Run bathroom and kitchen exhaust fans (in the absence of fans, open windows); remove moisture as it is produced by using exhaust fans. In the absence of fans, open windows for a short time.
  • Measure how much moisture is in the air. To find the relative humidity in your home, you’ll need a hygrometer. You can buy one at a hardware store or electronics store. A hygrometer costs from $10 to $60. Relative humidity in the home should be under 45 percent in the winter (or lower to avoid condensation on windows). If necessary, use a dehumidifier to lower the relative humidity.
  • Reduce the number of stored materials, especially items that are no longer used, such as clothes, paper and stored furnishings. Molds grow on fabrics, paper, wood and practically anything that collects dust and holds moisture.
  • Dehumidify the basement during the warm months.
  • Replace carpets on slab-on-grade or below grade floors with another type of flooring.
  • Clean and replace furnace filters. Use a pleated one-inch filter, not a coarse filter.
  • If you have a heat recovery ventilator (HRV), clean the filter inside the HRV.
  • If you notice molds, use well-known tips for cleaning to remove the fungi (find some here).
  • If you have electric baseboards, vacuum the units or have a professional clean them.
  • Vacuum often, preferably using a vacuum cleaner with a HEPA filter.
  • Clean hard floors with a damp mop.
  • Cut down on the number of potted plants in the house. Soil is a prime place for mold to grow.
  • Regularly check the condition of the roof and exterior finish for any places where water might enter.
  • Make sure that eavestroughs and downspouts are connected and working properly and that they are free of debris.

As an agent working with a buyer, consider asking the seller to:

  • Fix all water leaks, including slow leaks in outside faucets.
  • Add exhaust fans in all bathrooms and kitchens.
  • Add a house dehumidifier.
  • Replace carpets that are on top of slab-on-grade concrete or on floors that are below; grade (moisture lives in the fabric and can prompt mold growth).
  • Install a covered sump pump.
  • Replace a well-worn roof or badly damaged eavestroughs.
  • Pay for all mold analysis and clean-up by a professional.
  • Finally, talk to your buyers about putting in a very competitive offer, due to the mold.

Romana King is an award-winning personal finance writer, a real estate expert and speaker. Romana is the current Director of Content for Zolo Realty, one of Canada’s leading online real estate websites.

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