Blown-In Insulation: How It Works and Why It Matters

In a place like Renfrew County—where winters are long and cold, and summers can bring their own heat challenges—insulation is one of the most important parts of your home’s construction. One of the most effective and cost-efficient ways to improve your home’s comfort and energy performance is by upgrading or installing blown-in insulation in the attic.

How it Works

Blown-in insulation is a loose-fill material, usually made of either cellulose or fiberglass, that’s applied using a blowing machine. The machine feeds the insulation through a long hose, allowing it to be directed evenly across your attic floor. This method covers not just open areas, but also wraps around wiring, ductwork, and other obstacles that batt insulation often misses. The result is a seamless, continuous layer of insulation that fills in all the gaps.

What makes blown-in insulation so effective is the way it traps air. It’s not the insulation itself that stops the heat—it's the still air held between the fibers. Air is a poor conductor of heat, so the more of it you can hold in place within a thick insulation layer, the slower heat will move through your attic. In winter, this means warm indoor air stays inside where it belongs. In summer, it helps prevent heat from the roof from radiating down into your living space.

Attics are particularly important when it comes to insulation. Since heat rises, your attic is the number one place it tries to escape. If the attic is under-insulated, your heating system has to work harder to replace the lost warmth, which leads to higher energy bills and more wear on your furnace. The same idea applies in summer, when an uninsulated attic becomes a heat trap that makes air conditioning less effective and more expensive.

Installation Details

Before insulation is applied, it’s essential to ensure the roof is vented properly from the eaves to the ridge. Ventilation, along with the correct amount of insulation plays a big role in preventing ice dams. Ice dams can form when heat from the attic melts snow on the roof, causing it to refreeze at the eaves and create a barrier of ice. This ice can back up under shingles and cause roof leaks. By keeping attic temperatures consistent with the outdoors, blown-in insulation and correct venting helps reduce the chance of snow melt and refreezing, protecting your roof from damage.

The amount of insulation your attic needs depends on your location. In Renfrew County, we recommend insulation levels between R-50 and R-60, which typically means 12 to 15 inches of material, depending on the type used. Whether you’re starting with a bare attic or simply topping up what’s already there, blown-in insulation is one of the simplest and most effective ways to improve energy efficiency. An attic hatch upgrade is also a quick and simple way to prevent heat loss through the attic, and should be included with the insulation.

The installation process is straightforward and quick. Most homes can be vented and insulated in a few days, with minimal disruption. Once in place, the insulation requires virtually no maintenance and can last for decades if left undisturbed.

At Quality Homes & Renovations, we’ve helped many homeowners around Golden Lake, Barry’s Bay, and Round Lake make their homes more comfortable and efficient with properly installed attic insulation. If you’re not sure how well your attic is performing, it might be time to take a look. A warmer, more efficient home could be just a few inches of insulation away.