Mold, Fungus, and Mildew

mold window solid state home inspections

Author Update: In late 2016, Consumer Protection BC (the BC Government body overseeing home inspectors) added regulation that required inspectors clearly identify in their client contracts if they are inspecting for mold or asbestos. As standard contracts are provided or approved by home inspector insurance companies, the result has been that the standard client contract for professional home inspectors in BC now clearly state they DO NOT inspect for mold or asbestos. This was effectively the practice by most home inspectors but it is now much more clear for clients.

It only takes a short walk in a forest to notice that a part of natures cycle of life includes a cycle of death and decay. Large trees that fall in a forest will decompose back into the earth in only a few years with one of the leading contributors to this process being Fungi. There are hundreds of different types of Fungi but some of these fungi we call 'mold' when they have a particularly 'mouldy' appearance.

When you see mold in your home, nature is trying to return your home back to the earth which is not good for home owners, and is a trouble area for home inspectors.

What Conditions are Needed for Mold Growth?

Molds, like Mildews and other varieties of fungi, needs three key things to grow:

  • Food - Any organic product is food to mold. In our homes, wood studs, paper lined drywall, and plywood roof sheeting are all potential sources of food for mold.
  • Warmth - Most molds are dormant below 4C but starting at 5C and higher, there are many molds that can grow in our homes. The warmer the temperature, the more different molds types that will grow.
  • Water - Molds need about a 15% moisture level in organic material in order to grow. Wood used inside our homes should stabilize at about 8-14% moisture content.

As our western homes are typically warmer than 5C and are full of organic building materials, our homes are only one condition away from mold concerns and that missing ingredient is water. Keeping our homes dry is critical to keep mold from growing.

Common Areas for Mold Growth

Bathroom Mold Solid State Home Inspections

Mold growing on shower tiles in bathroom

Mold growing on basement walls after flood

Mildew on underside of roof common with roof venting issues and condensation.

Mold only needs warmth, organic material, and water in order to grow. Anywhere all three of these conditions occur, we can have mold issues:

  • Bathrooms - Bathrooms are very common place for mold growth as water in both liquid and vapour forms can soak into building materials if there are deficiencies in construction or maintenance. Home inspectors are very concerned about signs of moisture in bathrooms particularly around showers and baths. Often, mold is visible at the base of showers or tubs or as mildew on wall surfaces.
  • Kitchens - Kitchens use a lot of water for sinks and dishwashers. Back-splashes not sealed to countertops will allow water from counter cleaning to soak into wood cabinets below or faucets with leaks onto cabinets are common places for mold to grow in kitchens.
  • Windows - Condensation on the window surface as well as wind driven rains or poor window installation or maintenance can allow water into the home around windows. It is not uncommon to see mould growing on window surfaces and around the opening.
  • Basements - Water can seep into basements from cracks in the foundation or in some cases basements may be flooded due to rising water around the home or plumbing backups. Even small amounts of water can cause wide spread mold growth as it will often go unnoticed until the surface materials become damaged.
  • Attics - Attics and roof spaces that are not correctly ventilated can have condensation or leaks from ice dams and water vapour. It is common in poorly ventilated attics to see black mold/mildew growth on the bottom of the roof covering.
  • Structure - Water can seep into wood structure from unknown roof leaks, wood contact with the outside soil, or poorly built exterior walls and flashings. Wet wood can wick water long distances into the home causing extensive hidden damages.

Health Issues with Mold

Mold, like all funguses, use spores in order to reproduce. Spores from fungi exist in the billions in nature and humans are always in contact with them. There has been a lot of debate about the health impacts of mold in our homes with even the US government making accusations to the mold detection and abatement industry that they may be falsely representing the dangerous of mold in order to increase their business.

While there is some debate about the impact of spores on normal healthy humans, there is no doubt that people with compromised or reduced immune systems can have very serious complications including allergic reactions, toxic mycotoxin poisoning, and fungal infections. While there are extreme cases of health issues with mold, there are good cases for mold as the discovery of penicillin which is used to treat infections.

There are scientists working very hard on understanding the health impacts of household mold on healthy humans. This article only recognizes there are two sides to this argument but that people with any concerns should exercise caution with household mold.

What Do Home Inspectors Look for with Mold?

Home inspectors are at a disadvantage when it comes to mold for a few good reasons:

  • Non-Visible - Mold often grows in hidden places that are not visible to inspectors. As the professional home inspection practice is a visual inspection, home inspectors may not be able to see mold in a home inspection
  • Harm Level - Different types of mold have different levels of health risk and some, like penicillin, are even helpful to humans. Visual home inspectors cannot determine if visible mold is harmful or not, or how harmful it can be
  • Concentration Levels - It is the mold spores which risk being the most harmful to human health and home inspectors are not able to confirm the concentrations of mold levels visually.
  • Professional Industry - Like electricians and plumbers, there is a separate professional industry outside home inspectors with skills and tools for detecting, analyzing, interpreting, and remediating mold and other household air contaminants. Home Inspectors are generalists.
  • Insurance Coverage - Professional home inspectors carry professional liability insurance but insurance companies know that potential health risks of mold are major liabilities and they won’t provide home inspectors coverage to discuss mold issues as we are not mold industry professionals
  • Government Regulations - As of 2016 in the Province of BC, Consumer Protection BC (the Government body overseeing home inspectors) added regulation that required inspectors identify if they are inspecting for asbestos or mold in client contracts. As a result, the standard contracts used by professional home inspectors now clearly say professional home inspectors are NOT inspecting for mold or asbestos.

Due to the reasons above, professional home inspectors DO NOT look for mold or other indoor air quality issues. Even if there are visual signs of mold, home inspectors are not required by professional standards to make any report on it. If an inspector does report on it, it should only be to suggest evaluation by an expert and the inspector should not begin to diagnose the cause of the mold or any implications on the home or occupant health. Home inspection clients that want confidence their home air quality is clean need to hire separate investigators for this service.

Final Thoughts

While home inspectors cannot confirm the presence or absence of mold itself, damage done by mold and the circumstances that could lead to water ingress needed for mold growth, are areas home inspectors should be reporting on. For home inspectors, protecting clients from mold means trying to identify risks of unwanted water ingress. After all, a dry home will be free of mold, making it safe and solid for the client and their family.

By James Bell - Owner/Operator of Solid State Inspections Inc.