A lot of people ask mold removal specialists in Calgary what does mold need to grow? Well, there are three things. Read below for what they are.


Mold spores need moisture or damp areas to grow and reproduce and cause damage to your home and are a real health concern. Water from flooding is the main event that allows a lot of water to intrude all at once. Heavy rains can cause water to seep from under the house and dampen carpets or cement floors perfect conditions for mold growth. Perimeter tiles in good condition along with gutters and downpipes kept clear of debris are meant to  direct water away from your home even in rainstorms.  Less obvious are leaky roofs, pipes or windows, all of which are sneaky ways for moisture to accumulate unnoticed. Certain rooms in the home have excess moisture such as bathrooms, kitchen and laundry rooms, rooms with  the potential for mold to grow unchecked. Checking to be sure your home is watertight, windows, the roof and the whole structure have a good vapour barrier in place will prevent problems in the future.


Everything requires a food source and mold is no exception, think cotton, leather, wood, paper products or others. Mostly they grow well on porous materials (beds, couches) and often it is impossible to remove mold from these items.

Optimal Temperature

The best conditions for mold spores is between 32 degrees F (10 C) and 120 degrees F (48.8 C). Temperatures in the range of 70 degrees F (0 C) and 90 degrees F (32 C) are the most conducive for mold to grow. While these are optimum growing conditions you might be tempted to think freezing conditions might kill them. The reality is they merely become dormant until it warms up enough.

Aside from the three things mentioned above relative humidity levels of roughly 50% or higher will encourage the growth of mold. Consider investing in a hygrometer to measure the humidity levels throughout your home. Damp or dusty conditions can also  be a factor, so avoid accumulating piles of rags, clothes or other mold food sources. The other factor is stagnant air so good circulation throughout the home is essential to eliminate dampness and potential moisture, especially in attics, basements and crawl spaces.  This can explain why the move to make homes “airtight” can cause mold issues. Good ventilation is important because vents throughout the home are what remove water vapour from the home. Make sure all vents lead to an outside source otherwise water vapor is just being moved to another place in the home. Remember to utilize the fans to those vents in kitchens, bathrooms and laundry rooms so they can do what they’re designed to do and remove the water vapor.

Thanks to Calgary Mold Removal for their answer to the question what does mold need to grow.