We at Mrroofrepair.ca get calls from worried home owners that think they may have a problem with Mould. In this blog I have gathered some information together to help you understand what mould is and what you should do about it.

• Mould can be harmful or helpful — depending on where it grows.
• Mould needs moisture to grow.
• Mould does not grow on dry materials.
• Mould growing inside a home can affect the occupants.
• Moulds are undesirable when they grow where we don’t want them, such as in homes.
• Over 270 species of mould have been identified as living in Canadian homes.
• Any excessive mould growth can lead to increased allergies, toxicity, and house/building structural problems.

Paraphrased from

http://www.cmhc-schl.gc.ca/en/co/maho/yohoyohe/momo/momo_005.cfm

 Causes of a mould infested Home

• Most new homes are built on concrete slabs, which emit moisture for several years as they cure, and because they are porous, moisture from the soil beneath the slab also vaporizes into the living space.
• Leaky roofs, windows, and plumbing, whether caused by poor construction or lack of timely repairs, often result in colonization of mould and mildew spores.
• Poor Ventilation – If the air pressure in your home is “negative”, meaning the air pressure outside is greater than it is inside, then it will force moisture and contaminates back into the home.

Health Problems 

• Moulds growing inside the home may cause health concerns because moulds release chemicals and spores.
• The presence of mould is a sign that there is too much moisture in your home — a situation which must be corrected.
• Health experts indicate that, depending on the type of mould present in a home, the health effects of mould can range from being insignificant to causing allergic reactions and illness.
• Signs of Toxic Poisoning – Toxic black mould and other fungi produce Volatile Organic Compounds (VOCs). Exposure to high levels of VOCs may irritate the mucous membranes and the central nervous system leading to symptoms of headaches, decreased attention span, difficulty in concentration and dizziness.

Discoloration–Discoloration is a sign of mould. Mould may be any colour: black, white, red, orange, yellow, blue or violet. Dab a drop of household bleach onto a suspected spot. If the stain loses its colour or disappears, it may be mould. If there is no change, it probably isn’t mould.

Smell/Odour–Sometimes moulds are hidden and cannot be seen. A musty or earthy smell often indicates the presence of moulds. But a smell may not be present for all moulds. Even when you don’t notice a smell, wet spots, dampness or evidence of a water leak are indications of moisture problems and mould may follow.

 Get a professional

Consider seeking professional help from trained IAQ investigators to identify appropriate remediation steps inside the home. Removing large amounts of mould will require the services of mould clean-up contractors. You will need professional help when: 

• There is a lot of mould.
• The home is very damp and moist.
• Mould comes back after repeated cleaning.
• A family member suffers from asthma or respiratory problems or other health problems that appear to be aggravated inside the home.

Mould Prevention

• Regularly check the condition of the roof and exterior finish for any places where water might enter.
• Make sure that eaves troughs and downspouts are connected and working properly and that they are free of debris.
• Install downspout extensions to lead water away from the building.
• Deal promptly with any problems that you find.
• The air pressure in your home should be balanced.

 Misconceptions about how to treat Mould

Using Chlorine Bleach To Kill Mould – Do not use ineffective chlorine bleach to try to kill mould growth and mould spores. Bleach is too weak even when freshly manufactured to kill mould. Bleach that sits on store shelves and in your home continually gets ever weaker over the passage of time. Bleach is NOT an EPA-registered fungicide. If you want effective mould kill, use EPA-registered mould fungicide.

Using Other Ineffective Products To Kill Mould – Regular paint, paint containing a mildicide element, any paint, Lysol, ammonia, and other household cleaners and disinfectants. Painting over a mould problem does not solve it – it only hides the problem temporarily and gives the mould something delicious to eat: the paint itself.