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Written by Kayla Jane Barrie Updated on Nov 21, 2025 7 mins read

Blog Does Insurance Cover Mould Damage?

A guide to dealing with mould damage in your home

Mould is a common enemy of homeowners in Ontario. It’s not something you want to see. It’s a common result of water damage from flooding, leaks, and other issues. Growth can also happen over time in areas where water and moisture are present.

In your home, it poses a serious health risk and it can do significant damage which can be extremely expensive to repair and impact your home insurance in Ontario. As a homeowner, it’s vital to understand how to improve indoor air quality to keep your family and visitors healthy.

For these reasons, you need to care about mould, know how to deal with it and make sure you understand how your coverage relates to mould damage.

What you need to know about mould and your home insurance policy:

  • Policy coverage limits for water and mould damage may necessitate out-of-pocket expenses beyond the deductible if repair costs exceed the coverage amount.
  • Filing mould damage claims may lead to increased premiums, depending on the claim's cause and your insurer; frequent claims, regardless of type, will raise rates, so carefully weigh the costs and benefits before filing.
  • Renters should have tenant insurance and promptly report mould issues to their landlord; while most policies cover mould resulting from covered perils, damage due to neglect or poor maintenance is typically excluded.

What is mould?

Mould is a common term for any fungus that grows on damp materials. It is related to yeast, mushrooms, and other fungi. Even though it is a natural part of the earth, it often grows inside buildings and can be a health hazard when growing inside.

It can produce a potentially harmful substance called mycotoxins, which creates a variety of allergic responses or hypersensitivity diseases in people.

It can also cause physical damage to structures because mould can lead to rotting wood components of buildings, tiles, drywall, and carpets. Mould can also contribute to sick building syndrome, an illness where occupants experience symptoms of illness while inside, but the direct cause is not specified.

What you need to know about mould damage and home insurance

Where there are leaks, pooling water, and dampness, mould is never too far behind.

While mould from severe water accidents such as sewer backup or a burst pipe is commonly covered, it’s not uncommon for mould-related insurance claims to be rejected if growth has been present for some time. Insurers view this as neglecting home maintenance and it will not be insured.

Depending on your policy, you may have coverage limits related to water and mould protection. If the repairs go beyond your policy, you will have to pay out of pocket, after the insurance deductible is paid.

Since mould remediation can be expensive, it’s important to address leaks and mould damage as soon as an issue is identified. As soon as you experience damage, call your insurer and have it cleaned up by a professional. The longer you leave the issue, the more it will spread and the more difficult it will be to clean up.

Make sure you are aware of what is not covered in your policy and consider purchasing additional coverage to top up protection against water issues. In some cases, you may be able to purchase a mould rider to supplement your current coverage. Talk with a ThinkInsure expert about your options.

Understand mold coverage for your home: Get a free quote today!

Contact us today for a free quote and learn which types of mold damage are covered under our comprehensive insurance policies.

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Does renters insurance cover mould damage?

If you rent, not only is it crucial to have tenant insurance, but it’s important to speak with your landlord about any mould problems. Most policies will cover it, but only if it results from an accident caused by a covered peril. Similar to being a homeowner, mould from poor maintenance or negligence will not be covered by insurers.

Does insurance cover mould removal?

Insurance will not cover mould caused by negligence – but if you have a named peril in your policy that is covered, your insurer will help with the removal of it in your home.

For example, it will not cover mould that grows in your basement over a number of years because of a foundation crack that was not repaired. On the other side, if there was a storm that caused water to enter your home, and caused mould on the wall and under the carpet, you may be covered.

Will a mould claim increase insurance?

Depending on the type of claim, the cause of mould damage, and your insurer, you may see an increase in your premium. The more claims you submit, the more your rate is going to increase, no matter what the claim is for. Always evaluate the situation and associated costs to decide if it is worth making a home insurance claim.

Health risks of mould

Mould can be extremely hazardous to your health. Elevated levels of mould in your home can affect anyone who is exposed to it. If ingested, it can make you seriously ill, and in extreme cases, could cause death if you have an allergy or pre-existing medical condition.

Signs that mould or mildew may be present in your home include:

  • Runny nose and sinus congestion
  • Cough and throat irritation
  • Sneezing, chest tightness, wheezing, difficulty breathing
  • Headaches
  • Skin and eye irritation
  • Respiratory issues such as asthma

Some people are at a greater risk of the health effects of mould. Infants, the elderly, and people with respiratory issues are more sensitive to it. Some airborne moulds can cause lung infections and infect people with weakened immune systems.

See your doctor if you are experiencing these symptoms, and have your home inspected by a professional for the presence of it.

Where does mould grow?

Mould grows just about anywhere. It can grow on almost any surface indoors and outdoors. However, there are common areas that you should check:

  • Damp areas (laundry sinks, sump pump, bathrooms – especially shower tiles and the tub).
  • The kitchen.
  • In the basement and garage.
  • On walls and ceilings that have experienced water related accidents.
  • Rotting shingles and wood.
  • Underneath siding.
  • Outdoor stairwells where water is prone to pooling.
  • Anywhere else where water and moisture are present.

How to determine if you have mould

There is a very good chance you will have mould if you don’t properly clean up damage from water. Here are the ways you can identify its presence of it in your home:

  • Look: Look for visible signs in the common areas where it grows. Common areas include floors, windows, walls, and carpets. You’ll want to pay extra caution in bathrooms and kitchens.
  • Smell: A damp, mouldy, earthy smell is a common clue that it is present. You can contact an expert to help you if you have any concerns or need clarification.
  • Condensation: If you notice a lot of condensation on glass or metal, it can build up and turn into an issue.
  • Past Leaks: If you’ve had leaks and damage from water in the past it could create a breeding ground for it to grow.

Not all mould is simple to find, but if you pay attention to any visible signs or odours, you can catch the problem early.

How to prevent mould growth

While you won’t be able to completely mould proof your home, there are some proactive steps you can take to help prevent it from growing:

  • Professional Help: Use a professional for mould removal and to assist with cleanup.
  • Problem Areas: Know the common problem areas in your home and address them. Don’t allow areas to remain wet – clean up the moisture right away. Check basements, closets, window sills, sinks, tubes and pipes around the home.
  • Ventilation: Make sure your home is properly ventilated. Use kitchen and bathroom fans when cooking or bathing. Open windows and use indoor fans when necessary.
  • Humidity: Keep your home at the right humidity level and improve overall airflow. It is recommended to have low humidity levels – 50% in the summer and 30% in colder months. You can invest in a dehumidifier to help remove excess moisture in the air. Here are some tips on measuring humidity in your home.
  • Roof And Gutters: Make sure gutters and downspouts are in working order and make sure groundwater properly flows away from your home through proper land grading. Check if your roof needs replacement or repairs.
  • Cleaning tips: If you use a dehumidifier, humidifier, or air conditioner, ensure you spend time regularly cleaning and disinfecting them. Check to ensure tubs and sinks are properly sealed to prevent water from leaking into walls.

Mould damage cleanup – should you use a pro or DIY?

Mould cleanup is something that you need to take seriously. Whether mould is a result of flood or a sewer backup insurance claim, how you approach cleanup will depend on several factors.

The first thing you need to do if you find mould is to determine the size of the issue. You can clean up small areas of mould; however, a larger presence should be handled by a professional mould remediation company.

The US Environmental Protection Agency explains:

The US Environmental Protection Agency explains:

Who should do the cleanup depends on a number of factors. One consideration is the size of the problem. If the mouldy area is less than approximately 10 square feet (roughly a 3 ft. by 3 ft. patch), in most cases, you can handle the job yourself.

Other things to consider when determining whether or not to use a professional are:

  • Where is it located?: If it’s near an HVAC unit and could have gotten into the system, call a professional.
  • What is the source?: If the mould is a result of sewer backup or potentially contaminated water, a professional is your best option.

Types of mould found in homes

There are thousands of different types of mould. Some thrive inside the home more than others. To help you understand the various kinds, here are the three broad categories they can fall under:

  • Allergenic: This type is not toxic in and of itself, but can trigger allergic reactions such as asthma.
  • Pathogenic: This mould can trigger illnesses in people already weakened by other causes.
  • Toxigenic: The most dangerous because they create their own toxins that can lead to health problems that are sometimes lethal.

Common moulds found inside homes include:

  • Stachybotrys (black mould): Often found in damp areas and ventilation systems. They stem from too much moisture and poor indoor air quality.
  • Alternaria: This occurs in damp places indoors, such as showers, under leaky sinks, and the bottom of windows where condensation develops. It’s one of the most common types of allergenic mould.
  • Aspergillus: This often grows indoors, on dust, powdery food items, and building materials that have water related damage, such as drywall.
  • Penicillium: Don’t get this confused with the source of antibiotics – this blueish-green mould can cause allergies, trigger asthma, and travel easily.
  • Cladosporium: This can grow in either cool or warm areas on fabrics and wood surfaces.

Mould damage and insurance FAQs

Any black mould that was formed after a sudden accident may be covered under home insurance. For example, if a fire occurred and the water used to put it out caused mould, your policy would likely cover it. If you notice black mould around a leaky pipe, you will likely not be covered since it was caused by negligence and could have been prevented.

Your Toronto home insurance will cover attics that are affected with mould, if it was caused by accidental water related damage. If you need to submit a claim in Toronto for mould, be sure to review your policy and hire a professional to help determine the cause of the issue.

Dealing with mould can also be an issue for condominium owners. Many building owners say they are responsible for preventing it in common areas, but residents are responsible for their units. Be sure you have mould coverage in your condo insurance so if you need to make a claim, you will have some support.

Mould is a growing concern for homeowners - ensure you are properly covered with insurance

If you have mould from water-related accidents, it’s best to contact your insurer about your Ontario home insurance. They’ll be able to verify if you are covered and can help you start the process of cleaning up.

If you are not sure about the extent of your water damage insurance, contact our team today. We’d be happy to help ensure you have ample coverage to protect your home.

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Kayla Jane Barrie

Digital Content Writer

Kayla-Jane has been a content writer with ThinkInsure since 2020. She creates insurance content for auto, home, and commercial. Kayla-Jane has a diploma in Journalism.


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