Mould Dogs Inc. - professionally trained dogs to detect mould in commercial, residential and institutional buildings Mould Dogs Inc. - professionally trained dogs to detect mould in commercial, residential and institutional buildings

Frequently Asked Questions

Q. Do I have a mould problem?

A. If you answer yes to any of the following, then you may have a mould problem. Do you have chronic flu-like symptoms? Sore throat, cough, headaches, runny nose, watery eyes, always tired and lethargic? Or do you notice a stuffy or urine-like odour when you first enter your home from outside? If so, mould may be the cause. Some of the most common building moulds thrive on cellulose. Cellulose is found in the paper backing on wallboard, in carpeting, underlay and particle board. When mould digests these materials, various chemicals in these materials are released into the air, as a byproduct of the ‘mould process’. In the case of OSB (oriented strand board), (commonly used in place of plywood in modern homes), the glues used in the manufacture of the OSB almost always contain a chemical called urea. As the mould digests the cellulose, it emits the urea as a gas, resulting in a stale urine-like odour. Therefore, this type of odour may be a symptom of actively growing mould.


Q. What is toxic mould? (Sometimes called black mould)

  • (There are thousands of varieties of mould. Some are toxic; some are black. Not all toxic moulds are black; not all black moulds are toxic. There is absolutely no relationship between the colour of mould and its toxicity.)

A. Under certain conditions, some species of moulds (generally referred to as toxic moulds) may generate molecular compounds called mycotoxins. In large quantities or with chronic exposure, mycotoxins can be toxic (poisonous) to humans and animals. Mycotoxins can have both chronic and acute effects on human and animal health.


Q. Where did the mould in my home (or workplace) come from?

A. Mould spores are always present in both outdoor and indoor air. Unless certain conditions exist, mould cannot grow and the naturally-occurring, low levels of mould normally found in indoor air will not be a problem. However, under certain conditions, these floating spores take root and begin to form colonies. This process of mould growth requires 3 things to occur -

  • 1: the right temperature (indoor room temperature is generally ideal)
  • 2: nutrients (wallboard, carpet, even dirt and dust!) and
  • 3: moisture. The source of moisture could have been a leaking pipe, roof, window or siding, a crack in the foundation, overuse of a humidifier, broken bathroom exhaust fan, flood, etc.

(Note: The first step in fixing any mould problem is to identify and eliminate the moisture source. Until this is done, it will be impossible to get rid of mould permanently.)


Q. If I can't see any mould, how can it affect me?

A. Most mould spores are a fraction of the size of a human hair. Mould is only slightly larger than viruses and bacteria. It floats everywhere, passes through walls, most materials such as paints and even most plastics! The 3 most common health problems caused by mould are:

  • 1. Aggravating existing allergies - may affect different people in different ways or sometimes not at all.
  • 2. Infections – such as Farmer’s Lung. (In general, persons with immature or weakened immune systems, such as children, seniors, persons on chemotherapy or similar treatments, etc are more susceptible to illness caused by mould. Even taking antibiotics can worsen the effects of mould!)
  • 3. Toxicity (poisoning) – while mould is digesting the cellulose found in building materials, it can emit toxic vapours (Volatile Toxic Organic Compounds) as a biproduct of this process. Inhalation of these vapours can cause extremely serious health problems.


Q. What is the difference between viable mould and non-viable mould?

A. Viable mould is mould that is actively growing and is capable of reproducing. This form of mould generally causes more significant health problems than non-viable mould. Non-viable mould is simply mould which has become dormant; due to a lack of one or more of the prerequisite requirements: temperature, nutrient and/or moisture. However, non-viable mould is NOT dead. It can still cause significant health problems and will begin growing again, even after many years of dormancy, when conditions are again favourable. In some respects, mould is more dangerous in its non-viable form, because it has dried into a fine dust and can easily migrate to another location if there is the slightest air current.


Q. What Can I Do? What is involved in removing mould?

  • 1.Find out how bad the problem is. Traditionally this means penetrating and/or removing interior wall coverings in a hit-and-miss fashion to see if mould is growing inside the walls. Similar destructive testing is used on floors and ceilings.
    (This is one of the key advantages of the mould dog: no destructive testing. The dog will alert to the exact location of the non-visible contamination. Repair costs in a large home or commercial space can be dramatically reduced by pinpointing the affected areas, thereby avoiding unnecessary lab testing and remediation.)
  • 2. As a general rule of thumb, if the mould covers an area less than 10 square feet (1 square metre) AND the moisture source has been eliminated, it may be possible to remove much of – but not eliminate - the mould by cleaning the affected area with bleach. However, once the area has been cleaned, use a hair dryer to thoroughly evaporate the moisture remaining from the bleach Otherwise, the mould will grow right back. And always wear a mask to avoid inhaling both the bleach fumes and the mould spores. Also understand that while you are removing some of the mould, at the same time you are rubbing many of the tiny mould particles deeper into the surface of the substrate! Where it will patiently lie dormant - for years if necessary - until some source of moisture allows it to start growing again.
  • 3. If the affected area is larger than 10 sq. ft (1 sq. metre) it is extremely unwise to attempt to remove it without professional help. In this case, proper containment of the affected area is absolutely crucial to avoiding contamination of the rest of the premises. (Removal of significant contamination should always be done in a similar manner to removal of asbestos).
  • 4. Don't bother with ‘miracle’ products sold on the internet. Don't paint over mould. It doesn't work.
  • 5. At the very least, if you believe you know where the mould is located, try to seal the affected area temporarily with heavy-gauge poly (minimum 6 mil thickness - mould spores are so tiny they will simply leak through anything thinner!) and make certain that any hot air registers and returns in the affected areas are tightly sealed. This may reduce the health risk and spreading of contamination while you are deciding on a plan of action.


Q. Is it OK to have the same company do both inspection/testing and repairs?

A. Most professional associations discourage (or even prohibit) their members from wearing both hats for obvious reasons. It isn't unusual for mould remediation costs in a large home or commercial premise to reach or exceed $50,000 - $100,000! So there could be a temptation to exaggerate the inspection results in order to justify expensive and unnecessary repairs. Similarly, there may be a temptation by the contractor to cut corners on proper (expensive) cleanup procedures - which has been known to result in the entire building being contaminated! Finally, reconstruction should never be authorized until an independent inspection company confirms that the cleanup has in fact been properly completed. Again, this is where the mould dog is the ideal solution to ensure that all sources of contamination – invisible or not - have been identified and removed.


Q. Finally, what can I do to prevent mould?
Since mould spores are like dust and can be found everywhere, the real question is: How can I prevent mould from becoming a problem?

A. The single, most important thing you can do is to ensure that relative humidity is never excessive (never above 60%) and that any leaks are repaired immediately. (Mould will ALWAYS begin growing in ANY temperate location and on ANY substance where moisture has been standing for 24 - 48 hours - as long as there is a food source (cellulose, dust, etc).


In summary, Why a Mould Dog?

  • -A mould dog pinpoints the exact location of hidden mould; therefore remediation (repair) costs can be dramatically reduced.
  • -A mould dog pinpoints source of mould. The cost of expensive air samples is reduced by restricting air sampling to only those locations where contamination is actually present. (eg: Rather than having to take an air sample in each room of a home, secondary sampling might only be required in a single room.)
  • -A mould dog ensures that air samples are as representative of the actual conditions as possible. (eg: If severe contamination exists behind the wall in one corner of a room, but the air sample is taken on the other side of the room, the actual ‘counts’ of mould may be significantly reduced, which would have the effect of understating the seriousness of the situation.)
  • -A mould dog provides immediate results; Traditional methods require laboratory evaluation and take several days to 2 weeks for results. In the meantime, a bad problem could be getting worse.
  • -A mould dog provides the best possible ‘clearance’ testing. Once all contaminated material has been removed, but before reconstruction begins, the mould dog can quickly and precisely locate any remaining contamination that may have been missed during the demolition (again because much mould is not visible to the human eye.) This ‘clearance’ test also ensures that the demolition process has not spread mould into previously unaffected areas - especially the ventilation system.


Q. Is the dog affected by the mould?

A. A trained scent dog ‘sniffs’ the air to detect an odour, whether that odour is fire accelerants, explosives, a cadaver, illicit drugs, cancer, termites or any other odour that the animal has been trained to detect. These dogs do not have to ‘breathe’ the air in order to do their job. They use their olfactory glands to analyze the air, detecting odours in parts per trillion – an absolutely minute quantity, less than even the most sensitive detection devices can measure! Which means that they require only a few moments in a room to alert to an odour.

Nevertheless, the dog is never taken into any area: a) which contains visible mould b) where the handler would need to wear a mask or respirator due to unpleasant odours c) which has been declared unfit for human habitation In all of these cases, the mould contamination is so severe that extensive reconstruction is a certainty and therefore the dog serves no useful purpose.

Mould Dogs Inc: Why Take a Chance When You Can Be Sure.

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