The 30-Second Verdict
Blown-in insulation is the cost-effective choice for standard Florida attic insulation upgrades — delivering excellent R-values at reasonable cost. Spray foam (especially open-cell applied to the roof deck) creates a conditioned attic that eliminates Florida's brutal attic heat problem and better protects HVAC equipment, but costs 3–4x more. For homes with ductwork in the attic, spray foam pays back faster.
Head-to-Head Breakdown
Spray Foam Insulation
Pros
- Creates conditioned attic — no hot attic problem
- Excellent air sealing (no separate step needed)
- Protects HVAC ducts from extreme heat
- Can eliminate need for attic ventilation
Cons
- 3–4x more expensive than blown-in
- Requires professional installation
- Open-cell can absorb moisture if roof leaks
- Hard to remove or modify later
Blown-In Insulation
Pros
- Much lower cost per R-value
- Easy to add over existing insulation
- DIY possible (blown-in kits available)
- Rebates available from FL utilities
Cons
- Leaves attic unconditioned (still very hot in FL summer)
- HVAC ducts still in hot attic space
- Requires separate air sealing step for best results
- Settles over time — check coverage periodically
Side-by-Side Comparison
| Spray Foam Insulation | Blown-In Insulation | |
|---|---|---|
| R-Value per inch | R-3.7 (open cell) / R-6.5 (closed cell) | R-2.2–2.7 (fiberglass/cellulose) |
| Cost (1,500 sq ft attic) | $4,500–$8,000 | $1,200–$2,500 |
| Air Sealing | Excellent (inherent) | Requires separate air sealing |
| Attic Temp (summer) | Conditioned (same as living space) | Still 140–160°F (unconditioned attic) |
| HVAC Duct Protection | Yes — ducts in conditioned space | No — ducts still in hot attic |
| FL Utility Rebate | Limited | Yes — FPL, Duke Energy, TECO programs |
| Best For | Homes with ducts in attic, new construction | Most existing FL homes, cost-conscious upgrades |
Frequently Asked Questions
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Top-Rated Local Florida Insulation Alternatives
You don't have to pick a national brand. These Florida-based insulation companies have the highest real Google ratings in our directory — often at a fraction of the franchise price.
Typical insulation services: Attic insulation, Spray foam, Blown-in insulation, +2 more
Insulation Plus of Tampa
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I-Foam & Insulation Inc
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