mouldMould, asbestos and vermiculite are often misunderstood. When people come across it – either through an inspection of a home that is being contemplated in a purchase or while living in their home – they have certain preconceived ideas that may not result in the optimal, most educated decisions on how to treat it in their specific situation.

Mould: Moulds are microscopic fungi that actually grow in every home. It is only a substantial amount of mould, affecting the structure of the home and/or toxic mould that should be a big concern.

If there is mould but it covers less than a square metre, it is considered “small” (even up to three small patches are not a significant concern).  In these cases, the homeowner can safely, quickly and effectively clean it up without the help of an expert. 

It is important to clean them when they are first noticed because it can become more of a problem if ignored. The homeowner must follow precautions to keep moisture levels in the home at a minimum. This can mean the difference between a few dollars and a couple of thousand if the problem is caught early and treated properly. The Home Inspection Network has a comprehensive document on mould that elaborates and can be found at

If the mould comes back after cleaning or it is located in larger areas, hiring an expert is recommended. This would be an experienced person who has come across mould issues and has practical knowledge of remediating. We do not recommend testing the air, because where it is determined that there is a mould problem, the cost of testing may be better spent hiring a professional investigator or fixing the problem.

Asbestos and vermiculite: Both asbestos and vermiculite are natural occurring minerals that have been used in a variety of commercial products, especially insulation, electrical products and in many products around the house (caulking, shingles) due to their ability to insulate and slow down fires. Both asbestos and vermiculite are now regulated, controlled and contained in products made since the 1990s.

Health Canada and the U.S. Environmental Protection Agency (EPA) state that asbestos and vermiculite, when contained and not exposed to the home or interior environment, pose very little health risk. They pose health risks only when fibres are in the air that people breathe. This can happen when asbestos-containing products break down, either through deterioration as they age or when they are cut. People can put themselves at risk – often without realizing it – if they do not take proper precautions when repairs or renovations disturb materials containing asbestos.

The agencies recommend that if you do not need to disturb the material, seal it up. This includes sealing all cracks and holes in the ceilings of the rooms below the insulation by apply caulking around window and door frames, along baseboards and around electrical outlets. Additional insulation can be put on top of the vermiculite, typically costing about $500 to $1,000, depending on the home and the insulation used.

If the homeowner is in doubt and/or wants to do some renovations or remodelling in the area, a professional who is trained and qualified to handle vermiculite and asbestos removal should be hired before proceeding with any work. These products, when disturbed, can spread throughout the home, causing serious health problems and more expenses down the road.

 This article was provided to REM by The Home Inspection Network, a network of professional, experienced and field-tested home inspectors and energy advisors, built with the real estate agent’s needs in mind. or call toll-free at 1-855-232-9778.


  1. Hi Mr./Miss inspector… “mould” … the range that it presents itself in a house … to what extent it become trouble some? Is there a test to test the air for Mould particles? If so, how much is the cost?


    • There are what are called Air Quality tests and this procedure is determined by a 3rd party to the transaction. A mould specialist comes in, takes some swabs and it is sent to a lab to determine just how many parts per whatever is in the house. This can cost in I would guesstimate the price of a home inspection or more. Hope this helps…..Danny

  2. my feelings is simple if a house has any of the problems re mould etc they should not be allowed to sell or get a mortgagte till it is corrected

    no exception

    and mold can start the day you move into an new house because of moisture leaks

    • ..have to agree. If an inspection and/or someone who actually knows what mould is or where to look for it, or know what it is…then this can be flagged before you drop any monies into it to start with. If the owner is not going to fix it, or allow the money to have it fixed by the new buyer/purchaser, then it can and will become an issue that they have passed on. It can be a very serious and costly adventure. The root problem has to be found first, and then it will have to be addressed before any attempts to fix it take place……Danny

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