What Type of Insulation is Best for an Attic in Winnipeg?

May 25

When it comes to places where heat escapes your home the most, it’s the attic. In Winnipeg, that matters. When temperatures drop to -40°C, poor attic insulation can cause your heating bills to skyrocket. Yet, rooms will never feel warm enough.

What type of insulation is best for an attic in Winnipeg? In most homes, blowing-in insulation makes the most sense. Why? It easily fills in gaps and thrives in attics, but you shouldn’t count out spray foam either as it dominates when it comes to air sealing and moisture control.

At Great Canadian Insulation, we help homeowners choose the right attic insulation for their home and budget. Let’s explore your options.

Why Attic Insulation Matters in Winnipeg

Heat rises, that’s basic science. During the winter your furnace has to work overtime to keep your home from feeling like an ice box. Without proper attic insulation, it’s easy for heat to escape through the roof.

Poor attic insulation results in:

Higher heating bills
Ice dams on your roof
Cold spots and drafts throughout your home
Moisture buildup and potential mold growth

Winnipeg experiences bitter cold winters. That’s why attic insulation matters, it keeps the heat where it belongs in your home.

Attic Insulation Options for Winnipeg Homes

When insulating your attic, you have two main options to choose from. Each has strengths and weaknesses depending on your goals and conditions of your attic. Let’s explore:

Blown-In Insulation

Blown-in insulation in Winnipeg is common in attics. Here’s what makes a difference:

Fills irregular spaces and gaps easily
Achieves high R-values with proper depth
Installs quickly (usually only a few hours)
Works well over existing insulation (given it’s in good condition)
Eco-friendly cellulose option available

Blown-in insulation is ideal for open space attics where coverage comes first. It covers every nook and cranny so you get consistent thermal protection across your attic floor.

That said, this option isn’t perfect. It doesn’t seal air leaks. If your attic has gaps around fixtures, vents or access hatches, air may escape. It can also settle and lose its effectiveness over time.

Even with its flaws, blown-in insulation is sufficient for most attics.

Spray Foam Insulation

Spray foam insulation in Winnipeg costs a little more, but it’s worth it. That’s because it outperforms blown-in insulation in several key areas.

Closed cell spray foam offers:

Highest R-Value per inch (R6 to R7)
Complete air sealing without the gaps or leaks
Moisture resistance
Added structural rigidity
Doesn’t settle or degrade over time

Open-cell spray foam has a lower R-value (R-3.5 to R-4 per inch), but expands to completely fill in irregular spaces. It thrives in attics where air sealing is important and moisture isn't a factor.

When spray foam is applied to the underside of the roof deck (creating a conditioned attic), it thrives. It works well in attics with complex layouts, plenty of penetrations or existing moisture problems.

The higher upfront investment offers lower energy bills and insulation that lasts. At Great Canadian Insulation, spray foam insulation is one of our specialities.

Blown-In vs. Spray Foam: Which is Better for Your Attic?

Both options can work in attics. However, it ultimately comes down to your situation.

Choose blown-in insulation if:

Your attic is open and accessible
You’re adding insulation over existing material
Air sealing isn’t a major concern
You want a cost-effective solution

Choose spray foam if:

Air leakage is a problem
Your attic has moisture issues
You want maximum energy efficiency
You’re converting your attic to a conditioned space
Long-term performance matters most

Trying to make the right decision for you? A professional inspection can identify air leaks, moisture problems and other factors that affect performance.

R-Value Recommendations for Winnipeg Attics

R-Value determines thermal resistance. Higher R-values mean your insulation will perform better. In Winnipeg’s climate, you need higher R-values than you would in places with milder weather.

Here are the recommended R-values for Winnipeg attics:

Minimum: R-50
Ideal: R-60

Manitoba building codes set minimum requirements, but it’s important to be higher than that to last through our dreaded winters. The extra insulation pays for itself by lowering your energy bills over time.

Here’s what you need to achieve these R-values:

Blown-In Cellulose: 16-20 inches of depth
Spray Foam: 8-10 inches (closed-cell or combined with blown-in

At Great Canadian Insulation, we measure your existing insulation depth. From there, we can help you choose the right option to hit the R-values you need.