What Causes Attic Insulation to Deteriorate?

Published on October 14, 2025

In most cases, attic insulation in homes across the Greater Toronto Area can last up to 20 years, offering some level of appropriate energy efficiency. However, many homeowners find themselves calling insulation companies in Toronto for attic insulation removal before those 20 years are over. This is often because the insulation has deteriorated due to a number of factors and needs to be replaced. At EcoComfort, a leading attic insulation company in Toronto, we help homeowners remove and replace contaminated insulation and help you maintain a healthy attic environment.

Here are some of the most common causes of attic insulation deterioration in Toronto. 

Water Damage

Moisture is one of the biggest threats to the longevity of attic insulation. Even small leaks in the roof or poorly sealed vents can let water seep into the insulation material. Over time, this moisture can cause insulation to clump, compress, and lose its effectiveness. In severe cases, soaked insulation can encourage the growth of mold and mildew, which not only damages the material but also affects indoor air quality.

The heavy snowfalls and seasonal rain in Southern Ontario make water damage a frequent occurrence that causes deteriorating insulation. When moisture gets trapped in the attic, it reduces the ability of insulation to retain heat, forcing your HVAC system to work harder and increasing energy bills.

If your attic has experienced leaks, it’s important to schedule an attic inspection with EcoComfort to determine whether you need insulation removal services. 

Attic Mold Infestations

Mold spores thrive in dark, damp environments, and once they begin to grow, they can spread quickly through insulation materials. Mold not only compromises the effectiveness of insulation but also creates significant health risks, especially for individuals with allergies or respiratory issues.

Once attic insulation becomes contaminated with mold, it’s virtually impossible to clean the mold away. The safest and most effective option is to hire a trusted insulation company in Toronto to assess the damage and carry out attic insulation removal. Afterward, new, blown-in cellulose insulation can be installed to restore comfort and safety in your home.

Rodents and Pests

Mice, squirrels, and other small animals often make their way into attics during colder months, using insulation for nesting material. Unfortunately, as they burrow and move around, they tear apart insulation and leave behind droppings and urine, which contaminate the area.

The result is insulation that no longer provides proper coverage or thermal resistance. Contaminated insulation can also lead to unpleasant odours and potential health hazards due to bacteria and allergens. As a result, insulation removal will be required to restore the cleanliness of your attic, improve your energy efficiency, and maintain healthy indoor air quality.

The Effects of Time

Even under ideal conditions, attic insulation naturally deteriorates with age. Over the years, insulation can settle, compress, or lose its structural integrity, reducing its ability to regulate indoor temperatures effectively. 

As the efficiency of attic insulation declines, homeowners often notice uneven temperatures throughout the house or higher energy bills. If your insulation is over 15 years old, it’s worth scheduling an attic inspection with our experts at EcoComfort to determine whether replacement is necessary. Regular maintenance and timely upgrades can prevent energy loss and improve overall comfort.

Restore Your Attic Insulation with the Experts at EcoComfort

Working with an experienced insulation company in Toronto, like EcoComfort, ensures that any old or damaged insulation is properly handled and replaced with high-performance blown-in cellulose insulation that meets your energy efficiency needs. We provide comprehensive inspections and a full suite of attic insulation services from attic mold remediation to ventilation and attic roof leak repair. 

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