Understanding R-Value: Why Spray Foam Leads the Pack
R-Value is the measure of an insulation material's ability to resist heat flow. The higher the R-Value, the better the insulation performs. Spray foam insulation consistently delivers the highest R-Value per inch of any commercially available insulation material.
R-Value Comparison
| Insulation Type | R-Value per Inch |
|---|---|
| Closed-Cell Spray Foam | R-6.0 to R-7.0 |
| Open-Cell Spray Foam | R-3.5 to R-4.0 |
| Fiberglass Batts | R-2.9 to R-3.8 |
| Cellulose (Blown) | R-3.1 to R-3.8 |
| Mineral Wool | R-3.0 to R-3.3 |
Why R-Value Per Inch Matters
In many applications, space is limited. Attic rafters, wall cavities, and crawl spaces have fixed dimensions. With spray foam's superior R-Value per inch, you can achieve better insulation performance in less space.
Example: To achieve R-30 insulation:
- Fiberglass batts: ~10 inches thick
- Closed-cell spray foam: ~5 inches thick
That's half the thickness for the same (or better) thermal performance.
Beyond R-Value
While R-Value is important, spray foam offers additional benefits that other insulation types can't match:
- Air sealing — Eliminates drafts and air leakage
- Moisture resistance — Won't absorb water or promote mold
- Structural strength — Closed-cell foam adds rigidity to walls
- Longevity — Maintains R-Value for 80+ years
The Bottom Line
When you factor in R-Value, air sealing, moisture resistance, and longevity, spray foam insulation delivers the best return on investment of any insulation material. Contact AT Foam at 425-999-8493 for a FREE estimate and R-Value assessment of your property.