Batt / Roll
Fiberglass Batts (Unfaced) Insulation
Complete guide to fiberglass batts (unfaced) insulation: R-value, installed cost, pros, cons, and best applications.
Key Specifications
2.9–3.8
R-Value per Inch
$0.30–$0.50
Material Cost/sqft
$0.80–$1.20
Installed Cost/sqft
18"
Depth for R-60
Cost Analysis (1,200 sq ft Attic)
| Option | Low Estimate | High Estimate |
|---|---|---|
| Material only (DIY) | $360 | $600 |
| Professionally installed | $960 | $1,440 |
*Estimates for a full install to Climate Zone 5 R-60 depth. Use the calculator for your specific situation.
+ Pros
- ✓Lowest material cost of any insulation type
- ✓Easy to cut and fit between standard joist bays
- ✓No vapor retarder — good for layering
- ✓Widely available everywhere
− Cons
- ✗Leaves gaps at edges and obstructions — air leaks
- ✗Less effective without air sealing
- ✗Must be installed carefully to avoid voids
- ✗Lower R-value per inch than mineral wool or foam
Best Applications
- →Accessible open attics with clear joist bays
- →Budget renovation projects
- →Adding a second layer over existing insulation
- →DIY installations by careful homeowners
Comparing Insulation Types
Fiberglass Batts (Unfaced) is a batt / roll insulation. With R-2.9–3.8 per inch, it is suited to applications where depth is not a constraint.
View full insulation type comparison →Explore Other Insulation Types
Is Fiberglass Batts (Unfaced) Right for Your Attic?
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