R-38 at 12.5 in. labeled thickness for high-R 16 in. o.c. cavities
Key features
16 in. module width aligned with common residential joist spacing
Unfaced PINK Next Gen for designer-led vapor and air-barrier strategies
Technical specifications
| R-Value | 38.0 |
|---|---|
| Thickness | 12.5 in |
| Width | 16.0 in |
| Length | 48.0 in |
| Coverage | 42.67 sq ft/pack |
| Material | Fiberglass (PINK Next Gen), unfaced |
| Fire rating | ASTM C665; unfaced glass fibers classified noncombustible per ASTM E136 in manufacturer documentation. Unfaced PINK Next Gen acceptable ICC construction types I through V when installed per Owens Corning literature. |
| Sound rating | Cavity-fill fiberglass improves typical assembly STC versus an empty cavity; final acoustic performance is assembly-dependent. |
| Density | Light-density flexible batt per ASTM C665 manufacturer listings; see TDS for product-specific values. |
| Thermal conductivity | Nominal R-value at labeled thickness; see manufacturer TDS (ASTM C518) for tested conductivity. |
| Framing width | 16 in. width for 16 in. on-center joist or stud spacing |
| Construction type | Wood-frame and light-gauge metal-frame cavity construction |
| Application area | Attics, floors, and roof/ceilings; wood- and metal-framed cavities per code and Owens Corning literature. |
Product details
About 42.67 square feet per package (IDI-listed coverage). Primary use: 16 in. on-center floor, ceiling, and compatible roof assemblies where a 16 in. wide unfaced R-38 batt fits the structural depth and energy target.
W64 lists 12.5 in. labeled thickness with 16 in. width and 48 in. length on IDI Insulation, which matches common 14-1/2 in. clear bays on 16 in. modules for attic floor joists and flat ceiling framing. Unfaced construction keeps the insulation as thermal and acoustic cavity fill while the project team places vapor control where the climate package requires it—important when attic floors sit above conditioned space or when exterior foam changes winter drying potential.
PINK Next Gen marketing emphasizes low dust, soft handling, and stiff batts that recover quickly from packaging; those traits matter when inspectors are watching for full contact with the drywall lid or roof sheathing plane without chronic voids at joist heels.
Estimating should use this SKU’s distributor-listed coverage, not a generic R-38 constant from another width or length. Download the current PINK Next Gen Fiberglas insulation product data sheet linked by IDI for authoritative statements on fire performance, recycled content, and installation constraints.
Documents & certifications
Technical data sheet
Manufacturer-tested R-value, coverage, fire notes, and handling—use for submittals, RFIs, and field QA.
Download PDF (opens in new tab)Certifications & compliance
GREENGUARD (formaldehyde-free validated) per PINK Next Gen line documentation; UL Environment EPD; California Title 24 Article 3 insulating materials where applicable.
Frequently asked questions
W64 versus W65 at the same R-38—what changes?
W64 versus W65 at the same R-38—what changes?
Width and coverage per bag. W64 is 16 in. wide with about 42.67 square feet per package; W65 is 24 in. wide with about 64 square feet per package per IDI. Match the SKU to your framing module.
Do I need a separate vapor retarder with W64?
Do I need a separate vapor retarder with W64?
Often yes, depending on climate and assembly. Unfaced batts do not include kraft; follow IECC and local amendments for vapor retarder placement.
Is this batt noncombustible?
Is this batt noncombustible?
Manufacturer literature classifies unfaced glass fiber insulation as noncombustible per ASTM E136; still install with required thermal barriers and occupancy separation per code.
Can I compress W64 under a raised storage floor?
Can I compress W64 under a raised storage floor?
Compression reduces effective R-value. Either preserve full thickness or choose a different insulation approach for that zone.