Which Type Should You Choose for Your Peoria Home?
I've been installing spray foam insulation in Peoria and Central Illinois for twelve years, and this is the question I hear more than any other: "Should I use open cell or closed cell spray foam?" The answer isn't one-size-fits-all—it depends on your specific situation. Let me break down what I've learned from thousands of installations, so you can make the right choice for your property.
Here's the simplest way to think about it: Both types of spray foam start as a liquid that expands and hardens. The difference is in how their cells are structured.
Open cell foam has cells that aren't completely sealed—they're open to each other, like a sponge. This makes it lighter, softer, and less dense. It expands more aggressively during application, which is why it fills gaps so effectively. The downside is that it's more permeable to moisture and offers a lower R-value per inch.
Closed cell foam has cells that are completely sealed off from each other. This creates a rigid, dense, moisture-resistant barrier. It's heavier, more expensive, but delivers superior insulation performance and acts as a vapor barrier all by itself.
| Property | Open Cell | Closed Cell |
|---|---|---|
| R-Value per Inch | 3.5-3.8 | 6.0-7.0 |
| Density | 0.5 lbs/cubic ft | 1.5-2.0 lbs/cubic ft |
| Moisture Barrier | Limited | Excellent (vapor barrier) |
| Structural Support | None | Yes—adds rigidity |
| Sound Dampening | Excellent | Good |
| Cost per Sq Ft | $0.44-$0.65 | $1.00-$1.50 |
I recommend open cell spray foam for:
Real Example: A Peoria homeowner wanted to insulate their second-floor attic with a $2,000 budget. I used open cell to cover 1,200 sq ft with 5.5 inches (delivering R-19). Closed cell would have only covered 700 sq ft. The open cell choice was perfect for their budget and their attic's low-moisture environment.
I always recommend closed cell spray foam for:
Real Example: I worked with a homeowner in East Peoria who had mold growth in their crawl space. The previous contractor used fiberglass—moisture just soaked through. I removed it all and installed closed cell spray foam. Five years later, zero moisture issues. The vapor barrier built into the foam changed everything.
For a typical 1,500 sq ft attic or crawl space application:
Yes, closed cell costs more upfront. But here's what I tell my customers: Peoria winters are cold. A properly insulated home with closed cell foam can save $1,000+ annually on heating compared to old fiberglass. The extra upfront cost often pays for itself in 18-24 months through energy savings.
If you're insulating a crawl space, rim joist, or any area with moisture risk—invest in closed cell. The vapor barrier it provides is worth every penny in our climate. If you're doing a dry attic on a tight budget, open cell gets the job done and saves you money without sacrificing performance.
The worst choice? Doing nothing. Peoria winters demand proper insulation. Whether you choose open or closed cell, upgrading from old fiberglass or missing insulation will pay for itself through lower energy bills and a more comfortable home.
Get a free assessment from a local spray foam contractor. We'll inspect your current setup, explain your options, and give you a real estimate.
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