When it comes to insulating your home in Iowa, the two most common options are spray foam insulation and fiberglass batts. Both can help regulate indoor temperatures, but they perform very differently — especially in Iowa’s extreme seasonal weather. So which one should you choose?
Let’s break down the pros, cons, and hidden differences that homeowners often miss when comparing these two
Iowa Weather Demands More Than Just R-Value
In a place like Iowa, where winters are frigid and summers are muggy, you need more than just “good enough” insulation. While both fiberglass and spray foam can technically achieve similar R-values, the way they insulate is where things really start to differ.
Fiberglass acts like a blanket — it slows heat transfer.
Spray foam acts like a seal — it blocks both heat and air leaks.
If your home has drafts, inconsistent temperatures, or high energy bills, that seal matters more than you might think.
What is R-Value?
Cost: Upfront vs Long term
- Fiberglass insulation is cheaper upfront. You can install it yourself, and the materials are widely available.
- Spray foam insulation costs more to install professionally — but you often make that money back within a few years in energy savings.
A well-sealed home reduces HVAC workload, cuts monthly bills, and can even extend the life of your furnace or AC. In the long run, spray foam often pays for itself.
Which one Protects Your Home Better?
| Feature | Fiberglass | Spray Foam |
|---|---|---|
| Air sealing | ❌ Not effective | ✅ Excellent |
| Mold & moisture control | 🚫 Absorbs moisture | ✅ Repels moisture |
| Pest resistance | ❌ Can attract pests | ✅ Closed cell is pest-resistant |
| Longevity | ⚠️ Can degrade | ✅ 20+ years stable |
Fiberglass can sag or shift over time, especially in attics or wall cavities. Spray foam hardens in place and doesn’t move.
Installation Differences
- Fiberglass is a DIY option, but poor installation can cause gaps or compression.
- Spray foam must be applied by a trained pro — but when installed correctly, it fills every crack and cavity perfectly.
And unlike fiberglass, spray foam doesn’t require a vapor barrier in most cases, simplifying your project.
So… Which Should You Choose?
If you’re on a tight budget and need a quick upgrade, fiberglass might be the right short-term choice.
But if you’re looking for comfort, efficiency, and long-term performance — especially in Iowa’s unpredictable weather — spray foam is the better investment for most homes.
📞 Need Help Deciding?
We work with experienced local spray foam contractors right here in Iowa City.
Get a free quote today — just fill out the form on our homepage, and we’ll connect you with a trusted professional!