Mould – what is it?

Mould is a fungus that is related to yeast, mushrooms and other fungi. It can grow in a wide variety of environments including inside buildings. Although it is a natural part of the environment, Health Canada considers indoor exposure to mould a significant health hazard.

Moulds are very common in buildings and homes. Mould will grow in places with a lot of moisture, such as around leaks in roofs, windows, pipes, or where there has been flooding. When mould spores drop in places where there is excessive moisture, they will grow. Mould grows well on paper products, cardboard, ceiling tiles, and wood products. Mould can also grow in dust, paints, wallpaper, insulation, drywall, carpet, fabric, and upholstery.

Moulds can trigger a variety of symptoms, primarily as a result of allergic responses, although mould can cause certain diseases directly. Potential symptoms include itchy eyes, throat irritation, stuffy nose, coughing, wheezing, headaches, fever and shortness of breath. Infants, children, the elderly, and those with existing health conditions are at greater risk—including those experiencing severe cases of COVID-19. Prolonged exposure may be particularly harmful.

Mould can also cause physical damage to building materials including rotting of wood components of the building such as wall studs, floor joists and floorboards as well as damage to other building components such as ceiling tiles, drywall, and carpet. In extreme cases, mould can also cause structural issues if the decay is pronounced.

Mould has been identified as a cause of "sick building syndrome": a condition affecting a building wherein building occupant(s) may feel sick while they are in the building, but it is difficult to identify a specific cause.

Testing

Testing can determine the type of mould involved, although this is not usually useful information, as all moulds should generally be removed.

Testing surfaces

Staining may indicate that a surface has been water damaged while discolouration to surfaces may indicate mould growth.

Testing for mould can be done by either testing surfaces upon which mould is found. Hidden mould growth may be present behind materials if these materials were subjected to water damage in the past and have since dried out. They can be at increased risk of future mould growth if exposed to damp conditions in the future.

A lab will examine the samples under a microscope and assess the extent of the mould growth. The extent will be classified as sparse, moderate or abundant. The presence of mould spores without other fungal structures associated is assessed as follows:

  • a few spores (< 10 spores average per microscopic field at 400X),
  • some spores (10 – 100 spores average per microscopic field at 400X),
  • many spores (> 100 spores average per microscopic field at 400X).

The presence of a few spores generally represents settled spores on the surface of the sample rather than indicating mould growth.

Testing air quality

Testing can also be done by testing air quality.

Currently, there is inadequate scientific evidence to establish a clear relationship between airborne spore concentration and adverse health symptoms. As a result, there are no exposure limits or numerical guidelines for airborne spore concentrations exceeding which would indicate a health risk to building occupants. Health Canada does not recommend air sampling, presumably for this reason – it provides information that is not useful in dealing with a mould problem.

Remedial work

The first step in dealing with mould is to eliminate the damp conditions that gave rise to the growth of the mould. Then the mould itself should be removed. There is little point in removing mould if the damp conditions that gave rise to the mould have not been adequately remediated, as the mould will just regrow.

In some cases, mould can be dealt with by cleaning and disinfecting. In extreme cases, extensive remediation work can be required to remove contaminated drywall, framing and other affected building components.

Here is a basic checklist to remediate the situation yourself:

  • Remove or replace carpets and upholstery that have been soaked and cannot be dried promptly.
  • Clean up and dry out your home thoroughly and quickly (within 24-48 hours) after any flooding. Dig out mud and dirt.
  • Scrub cleanable surfaces (such as wood, tile, and stone) with soapy water and a bristle brush. Thoroughly clean all hard surfaces (such as flooring, trim, wood and metal furniture, countertops, and sinks) with water and dish detergent.
  • Dry surfaces quickly and thoroughly after cleaning.
  • Use a fan, air conditioner or dehumidifier to help the surfaces dry after you finish cleaning.

Consider professional assistance. You may be able to clean a small area of mould on your own, but a larger presence should be handled by a professional restoration contractor.

Prevention

You can control mould growth by:

  • Controlling humidity and moisture levels;
  • Promptly fixing leaky roofs, windows, and pipes;
  • Thoroughly cleaning and drying after flooding;
  • Ventilating showers, laundry, and cooking.

HEPA air filters can be useful in filtering out airborne mould spores that might otherwise trigger allergic or other reactions.

Your home should be checked routinely for signs of mould. It could appear as a fuzzy discolouration on surfaces, often accompanied by moisture. It may also be accompanied by a damp or musty odour. Watch for obvious signs of leaks, condensation, or flooding. The source of moisture may also be hidden, so it is important to check behind walls or above ceiling tiles—especially if water damage has occurred. Mould can grow quickly, so it is important to deal with latent dampness immediately.

Moisture problems are usually preventable. The longer damp conditions are allowed to remain, the more mould is likely to grow and spread and the more difficult and expensive it will be to clean up.

The Role of Homeowners Insurance

You may be covered for damage caused by mould in your homeowner's policy, although not all policies provide this coverage as standard coverage.

The first step is to review carefully your homeowner's policy to see what is covered and what is not. There may be specific exclusions for mould damage in your policy.

Your insurer or lawyer can help you understand your policy and make recommendations. If mould is not explicitly covered, you may be able to purchase "riders" or other additional insurance to get the most comprehensive protection.

Typically, if sudden water damage occurs, your policy will provide coverage. This would generally extend to consequential damage such as mould. In that cases, your policy would cover the cost of repairs. However, if the problem goes unnoticed or is allowed to persist for an unduly lengthy period of time, you may jeopardize your coverage.

Making a Claim

Contact your insurer if you have damage from mould or if you need to pay for mould clean-up. Once your coverage is confirmed, your insurer can assist with the cleanup and repair process. A representative of your insurer will likely inspect the damage as part of the claims process. Document the situation yourself with notes and photographs.

After your claims and clean-up are complete, check the area regularly to ensure all underlying issues have been resolved.

Conclusion

Mould in your home is a significant health hazard and it may in extreme circumstances threaten the structural safety of your home. Each season, take the time to inspect everything in your home to detect moisture and mould problems. If the pandemic has caused you to allow routine home maintenance to lapse, now is a good time to get back on track.

*This Blog Was Co-written by Student-at-Law David Heppenstall*

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.