How to Avoid Buying a House with Mold

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How to Avoid Buying a House with Mold

Buying a home is an exciting – but stressful process. It can be hard to find a house that fits all of your needs – from the location to the layout to the selling price. It can be easy to get ahead of yourself when you find the seemingly perfect house and buy it right away. In some cases, this can easily lead to the huge mistake of buying a house with mold. 

Now, nearly every home has some amount of mold present. Some types of mold can be harmless in small amounts. An overgrowth of mold or dangerous types can lead to disaster. Every year, Americans spend a total of $3.7 billion on health issues that are directly caused by exposure to mold. 

Buying a house with mold can wind up costing you much more than you want to pay. Removing mold can be extremely expensive – but the damage to your family’s health could cost you even more. 

So, here are some tips to help you avoid the mistake of buying a house with mold issues. 

1. Where Does Mold Grow in a House?

mold behind cabinets

As you walk around the home, look around for spots where mold is more likely to grow, such as on the floorboards, behind cabinets, and on spaces around pipes or vents. Mold grows best in dark, moist places, so you may want to use a flashlight to inspect dark corners in the bathroom or basement.

When you are viewing the home, you should do some visual inspection of your own to see if you spot any visual signs of mold. Mold can come in all kinds of colors and textures, depending on the type. Some of the most common household molds include:

  • Acremonium: This mold appears as a fine powder that can be white, pink, grey, or orange.
  • Alternaria: Look out for dark green or brown spots that appear to have a soft, velvety texture.
  • Aspergillus: This kind of mold can grow into thick layers and is often white, yellow, or green.
  • Chaetomium: This mold grows around water damage, and it is usually brown, grey, or black. It appears like a stain on the walls and creates a distinct musty smell.
  • Cladosporium: This type of mold is commonly found in carpets and upholstery. It blends into the fabric well since it has a suede-like texture and can be olive-green or brown.
  • Mucor: If you spot any thick patches of white or grey hair-like forms, watch out. This mold often grows underneath damp carpeting.
  • Penicillium: This mold creates a rather pretty blue or green colored patch with a soft, velvet texture.
  • Stachybotrys: Commonly known as black mold, this extremely toxic mold grows in patches that can be black or very dark green.
  • Trichoderma: This kind of mold forms wooly clusters that can be green, white, or yellow.
  • Ulocladium: You will often find this mold growing around cracks in the tile or floorboards. It is black or dark brown.

All of these common household molds have been linked to significant health issues. Long-term exposure can cause respiratory troubles, including asthma complications, coughing, congestion, and sore throats. People with pre-existing conditions or immune system suppression are far more susceptible to these types of issues.

Some of the more dangerous and toxic types of mold can even cause severe and chronic health conditions. This is known as mycotoxigenic exposure, and it can cause:

  • Pulmonary fibrosis (scarring in the lung tissue)
  • Liver and kidney damage
  • Toxic nervous system
  • Pregnancy complications
  • Digestive and heart conditions
  • Cancer

Unfortunately, mold often grows in spots that you cannot see with a simple visual inspection, such as behind paint, wallpaper, and drywall. If you do suspect that the house has mold or you just want to be extra sure, consider booking a mold inspection before deciding if you’re ready to buy.

2. What Happens During a Mold Inspection?

what happens during mold inspection

It is highly recommended that you have a professional mold inspection before purchasing a home for numerous reasons. If you wind up buying a home with high levels of toxic mold, you may not even be able to move inside. Sellers may not be honest about their knowledge of mold presence – or they may have no idea there is any.

As a buyer, it is up to you to ensure that you identify any potential issues and discuss them with the seller before signing on the dotted line.

Thankfully, mold inspections are easy and quick to schedule and they generally take just a few hours to complete. A specially trained mold inspector will arrive on-site to check out signs of mold. They may ask you (or the current homeowner) some questions about any signs of water damage or spots to check out.

Next, they will walk through the home and check out the spot where mold is most likely to grow. This includes checking around HVAC systems, basements, and attics, as well as areas around pipes where there may be leaks.

To inspect hard-to-reach spots, such as underneath carpeting or drywall, they will use infrared cameras. This technology can detect trace amounts of moisture and mold with thermal imaging technology.

The technician may also use humidity readers to check the air’s moisture levels in various spots in the home. If any mold or suspected mold spots are found, they will take videos or pictures for recorded evidence. Some air or fiber samples may be collected for further testing back at the lab to determine which types of mold are growing.

You may also want to have an air quality inspection before buying a home in addition to a mold inspection. If mold is growing in the home, there is a high chance that other toxins could be present as well. Air quality inspections test for levels of asbestos, dust, pests, and chemical compounds which could be harmful to your health.

3. What Do You Do if the House has Mold?

cleaning moldy wall

Now, you may be wondering what to do if the home does have mold. 

It is not fair to say that you should avoid buying a house with mold under all circumstances. In some cases, the presence of mold can be mild and easily fixable. 

Non-toxic molds can be removed with a deep cleaning, especially on surfaces like tiles, sinks, or tubs. Bleach and heavy-duty cleaners can be used to scrub away mold – but you must wear gloves, face coverings, and protective clothing while doing so. You may want to hire a professional cleaning service to take care of this issue. 

If mold is growing in the carpets of the home, it is best to have it carefully removed and replaced. The floor beneath should be sprayed and cleaned out before a new carpet is installed to prevent this from growing again. Pieces of moldy drywall, insulation, or wallpaper can also be removed and replaced. 

You may also want to consider renovating areas of the home where mold has grown to add in better ventilation. Fresh, dry air can help to suppress mold growth. You can also purchase dehumidifiers for damp areas, such as basements.

In some cases, you can negotiate the removal of the mold before purchasing the home – especially if you have positive results from a mold inspection.


Household mold is a serious issue that you need to know about before moving into a new home. Thankfully, you don’t have to guess whether or not your new house has mold before buying it. Pre-purchase mold inspections are a wise precautionary step to take to ensure that you don’t wind up buying a house with mold in it.

If you have any questions about the mold inspection process or would like to schedule a walk-through, please contact Air-Labs. We provide home environment inspections, testing, and reporting in the Montreal, Laval, and Southern Quebec areas.

We even offer a free virtual consultation to get started!