Seal Air Leaks with Spray Foam Insulation

If your home feels drafty, has rooms with temperatures that never seem to match the thermostat or struggles with condensation in winter, insulation may not be the real issue. In many Saskatchewan homes, the bigger problem is uncontrolled air movement. Air sealing is about stopping that unwanted airflow so your home can actually hold the heat you’re paying for. 

How Much Heat Is Lost Through Air Leaks? 

Here’s a number that surprises most homeowners: Air leakage can account for 25–40 percent of total heat loss in a typical house. Our spray foam company sees issues with the building envelopes of many properties that can’t be solved with the simple addition of insulation batts.  

This means that even if your walls and attic have decent insulation, warm air can still escape through cracks and gaps. Every time heated air leaks out, cold outdoor air replaces it. Your furnace then has to heat that new air all over again. 

In Saskatchewan winters, where temperature differences between inside and outside can easily exceed 40 degrees, that constant air exchange adds up fast. 

What Air Leaks Actually Look Like 

Most air leaks aren’t obvious, since they’re not giant holes you can see. They’re small gaps spread all over the house: 

• Around plumbing pipes 

• Where wires pass through walls and ceilings 

• At rim joists where the house meets the foundation 

• At attic hatches and recessed lights 

• Along top plates inside walls 

Individually, these gaps don’t seem like much. Together, they can equal the size of an open window left cracked all winter. 

What Spray Foam Really Is 

Spray foam, often shortened to SPF, starts as a liquid. When it’s applied, it expands quickly and fills the space around it before hardening. Once cured, it becomes a solid barrier that blocks air movement. 

This is what makes it different from traditional insulation. Fibreglass and cellulose slow heat transfer, but they don’t stop air from moving through or around them. Spray foam does both jobs at once. 

Because it sticks to wood, concrete and metal, it’s especially useful in places where surfaces are uneven or hard to reach. 

Why Spray Foam Is So Effective for Air Sealing 

Air sealing is less about insulation thickness and more about continuity. Spray foam expands into cracks and seals them completely, even when the opening isn’t perfectly shaped. 

This makes it one of the most reliable ways to seal: 

• Rim joists 

• Attic penetrations 

• Crawlspaces 

• Basement headers 

• Framing joints 

Once those leaks are sealed, your existing insulation can finally perform closer to its rated R-value. Without air washing through it, insulation actually gets a chance to do its job. 

How Proper Air Sealing Changes Your Building 

Homeowners usually notice changes in three main areas. First, temperature consistency improves. Rooms stop feeling drafty, floors feel warmer and the house holds heat longer after the furnace cycles off. 

Second, heating systems don’t have to work as hard. When warm air stays inside, furnaces cycle less frequently. That can reduce wear on equipment and help control energy bills over time. 

Third, moisture problems often improve. Warm air carries moisture, and when that air leaks into cold spaces like attics or walls, condensation can form. By reducing air leakage, air sealing helps lower the risk of frost, damp insulation and mould growth. 

Is Spray Foam the Only Air Sealing Option? 

No — caulking, weatherstripping and gaskets still play important roles around windows, doors and trim. But they’re not practical for sealing complex framing areas, hidden cavities or large numbers of small gaps. 

Spray foam is often used where other materials simply can’t reach or won’t last. Once installed, it doesn’t sag, shrink or pull away from surfaces, which makes it a long-term solution rather than a temporary fix. 

Where Air Sealing Has the Biggest Impact 

In most homes, the biggest air leakage problems are found in attics, crawlspaces and rim joists. These areas connect directly to the outdoors and often have multiple penetrations. That’s why spray foam is commonly used alongside other insulation upgrades. Seal the leaks first, then let the insulation do its job properly. 

When you need to seal a building the right way, call South Forty Spray Foam. We serve the rural and urban communities in and around Yorkton with spray foam insulation, insulation removal, air sealing and commercial coatings.