Both spray foam and blown-in insulation offer powerful energy-saving benefits—but they work in very different ways. In this article, the Airlock Insulation team helps Northeast Ohio homeowners understand the real-world pros, cons, and costs of each option so they can make the right choice for their home and budget.
Why the Choice Between Spray Foam and Blown-In Matters
Choosing insulation isn’t just about R-values—it’s about safety, performance, installation methods, and long-term comfort. We’ve removed and replaced both types in over 500 homes across Northeast Ohio. The truth? Each has strengths… and trade-offs.
What Is Spray Foam Insulation?
Spray foam is a chemical mixture that expands and hardens into a rigid barrier. It’s available in two forms:
- Closed-cell (higher R-value, moisture resistant, more expensive)
- Open-cell (more affordable, softer texture, lower R-value)
Pros:
- Very high R-value per inch (up to R-7)
- Effective air and moisture barrier
- Can be used in hard-to-reach spaces
Cons:
- Contains petrochemicals and toxic off-gassing during application
- High material and labor cost
- Requires complete vacating of space during install
- Can trap moisture if not installed properly
- Hard to remove or modify later
We’ve seen homes where improper foam application led to rot, odor, or major tear-outs.
What Is Blown-In Insulation?
Blown-in insulation (especially cellulose) involves dense-packed recycled materials like paper, treated with borates for fire and mold resistance. At Airlock, we use Nu-Wool cellulose, known for its stability and air-sealing power.
Pros:
- Excellent R-value (~R-3.8 per inch)
- Fills gaps around wiring and joists
- Safer, non-toxic, no off-gassing
- Sustainable and eco-friendly
- Maintains performance even in cold Ohio winters
- Easy to remove or upgrade later
Cons:
- Lower R-value per inch than closed-cell foam
- Requires professional equipment and expertise
Side-by-Side Comparison
| Feature | Spray Foam (Closed Cell) | Blown-In Cellulose |
| R-Value per Inch | 6.5–7.0 | 3.2–3.8 |
| Air Sealing | Excellent | Excellent (when dense-packed) |
| Moisture Barrier | Strong | Moderate (depends on install) |
| Eco-Friendliness | Low | Very High (86% recycled) |
| Off-Gassing/Toxicity | High during install | None |
| Removal/Changes Later | Very Difficult | Easy |
| Installation Cost | High | Moderate |
What We Recommend (and Why)
At Airlock, we don’t use spray foam as a whole-home solution—we reserve it for small, targeted areas like rim joists and crawl-space walls. For attics and wall cavities, we’ve simply seen too many risks in older homes: chemical exposure, moisture trapping, and difficult future retrofits.
We recommend blown-in cellulose for 90%+ of homes in Northeast Ohio. Why? It’s safer, greener, easier to install and modify, and performs better with our AIRLOCK Air Seal system.
Real Homeowner Example
A homeowner in Painesville had open-cell spray foam installed in their attic in 2018. By 2023, they noticed musty odors and moisture issues. We removed the foam (a messy process), sealed air gaps properly, and re-insulated with Nu-Wool. The result? Better airflow, lower humidity, and stabilized temperatures.
Still Not Sure What’s Best for Your Home?
Let’s walk through your attic or crawl space together. We’ll show you what’s really going on—and explain your options clearly.
Book a free insulation inspection or a professional energy audit today with the trusted team at Airlock Insulation.
Built on decades of experience. Rooted in safety. Focused on your comfort.
