What to Compare
Compare Spray Foam Insulation and Blown-In Fiberglass/Cellulose using cost per sq ft, r-value per inch, air sealing. Check the exact product or local service proposal, then request matching written terms before choosing for your Florida home. Use the differences below to identify the questions that matter for your project.
Head-to-Head Breakdown
Spray Foam Insulation
Features and considerations
- Air barrier AND insulation in one product — eliminates infiltration
- Rigid — adds structural strength to walls and roof deck
Limits and questions
- Requires professional installation
- Cannot be re-used or recycled
Blown-In Fiberglass/Cellulose
Features and considerations
- Easy to add depth for increased R-value
- Good for retrofitting existing Florida attics
Limits and questions
- Air permeable — doesn't seal air leaks like spray foam
- Can absorb moisture if there's a roof leak — monitor in Florida
Side-by-Side Comparison
| Spray Foam Insulation | Blown-In Fiberglass/Cellulose | |
|---|---|---|
| Cost Per Sq Ft (attic) | Request an itemized quote for Spray Foam Insulation; compare the same scope and payment period. | Request an itemized quote for Blown-In Fiberglass/Cellulose; compare the same scope and payment period. |
| R-Value Per Inch | Closed-cell: R-6.5 | Open-cell: R-3.5 | Fiberglass: R-2.5 | Cellulose: R-3.2 |
| Air Sealing | Ask the Spray Foam Insulation provider to document air sealing for the exact offer. | None — must seal separately |
| Moisture Resistance | Ask for evidence for the exact Spray Foam Insulation product or local service; match it to your project conditions. | Good when dry — vulnerable to leaks |
| Florida Code Requirement (attic) | Verify the current requirements and applicable documents for your address and Spray Foam Insulation proposal. | Verify the current requirements and applicable documents for your address and Blown-In Fiberglass/Cellulose proposal. |
| Best Application | Ask the Spray Foam Insulation provider to document current quote and terms for the exact offer. | Ask the Blown-In Fiberglass/Cellulose provider to document current quote and terms for the exact offer. |
| Federal Tax Credit | Ask the Spray Foam Insulation provider to document current quote and terms for the exact offer. | Ask the Blown-In Fiberglass/Cellulose provider to document current quote and terms for the exact offer. |
| Fit for your project | Ask the Spray Foam Insulation provider to document current quote and terms for the exact offer. | Ask the Blown-In Fiberglass/Cellulose provider to document current quote and terms for the exact offer. |
Frequently Asked Questions
What R-value does Florida code require for insulation?
Walls: R-13 cavity + R-5 continuous or R-20 cavity. Floors over unconditioned space: R-19. Most Florida homes built before 2005 are significantly under-insulated by current standards.
Is spray foam worth it in Florida vs. blown-in?
Closed-cell spray foam on the underside of roof rafters (converting to unvented attic) is the premium Florida solution — it dramatically reduces attic temperatures and keeps HVAC ductwork in conditioned space. For attic floor applications, blown-in cellulose or fiberglass is the cost-effective standard.
Consumer resources
Use these official resources when evaluating an offer. They provide general guidance and do not establish a winner between these options.
- FTC: checking home-repair offers and written agreements — General consumer guidance; not evidence of either brand's price or performance.