NRC 1.10 / SAA 1.08 at 3 in. per ROCKWOOL USA AFB TDS
Key features
16 in. × 48 in. steel-stud format for dense interior layouts
Noncombustible stone wool with strong fire-reaction documentation
Technical specifications
| Thickness | 3.0 in |
|---|---|
| Width | 16.0 in |
| Length | 48.0 in |
| Coverage | 85.33 sq ft/pack |
| Material | Stone wool (mineral wool), ROCKWOOL AFB® |
| Fire rating | Noncombustible per ASTM E136; 0/0 ASTM E84 indices on ROCKWOOL USA AFB TDS; cite listed assemblies for fire ratings. |
| Sound rating | NRC 1.10 and SAA 1.08 at 3 in. nominal thickness per ROCKWOOL USA AFB TDS (11-2025). |
| Density | Nominal density >2.5 lb/ft³ per ASTM C167 on ROCKWOOL USA AFB TDS. |
| Framing width | 16 in. batt width for 16 in. steel-stud bays |
| Construction type | Interior steel-stud module (16 in. × 48 in. per ROCKWOOL USA AFB dimensional tables) |
| Application area | Interior partition walls and interior floor/ceiling cavities in commercial construction per ROCKWOOL AFB application statements. |
Product details
Three inches of stone wool in a 16 in. × 48 in. module is a common answer when interior partitions need more absorption than a 2 in. batt but must still fit commercial metal-stud depths without stepping to 6 in. specialty walls.
ROCKWOOL’s USA data sheet ties the 3 in. thickness row to NRC 1.10 and SAA 1.08 with a full third-octave table—use those numbers in acoustic narratives and insist on assembly testing when STC is contractual.
Fire claims remain consistent across AFB: noncombustible per ASTM E136 / CAN/ULC S114 language on the sheet and the lowest class of flame spread and smoke developed per ASTM E84. Designers still need the UL/Intertek design listing for hourly ratings.
Coverage can differ slightly between distributors; IDI quotes about 86.7 square feet per package for supplier part 329599 while the YEARS SKU name references 85.33 sq ft. Treat the master-pack label as the authority and adjust takeoffs if marketing pages disagree by a few tenths.
Installation discipline is unchanged: full contact, minimal voids at joints, coordinated electrical boxes, and air sealing aligned with the partition’s smoke migration story.
Download https://p-cdn.rockwool.com/syssiteassets/o2-rockwool/documentation/technical-data-sheets/commercial/afb-acoustical-fire-batts-techdata.pdf for the exact tables and footnotes before submitting to an AHJ or acoustician.
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
ASTM C665 Type I, ASTM C553 Type VII, CAN/ULC S702 Type I, ASTM E136 noncombustible, ASTM E84 flame spread 0 / smoke developed 0 (Class A per IBC Note 1 on TDS), UL GREENGUARD Gold and USDA BioPreferred 25% biobased per ROCKWOOL AFB product page
Frequently asked questions
Why does IDI show 86.7 sq ft but the SKU says 85.33?
Why does IDI show 86.7 sq ft but the SKU says 85.33?
Distributor marketing databases sometimes round coverage or revise packs. YEARS retains 85.33 sq ft to match the historical SKU naming; IDI currently lists about 86.7 sq ft for supplier part 329599. Verify the master-pack label and update your model if the factory changes the bundle.
What NRC should specifiers use?
What NRC should specifiers use?
Use the ROCKWOOL USA AFB data sheet: NRC 1.10 and SAA 1.08 for the 3 in. thickness row as of the 11-2025 issuance date.
Can AFB replace safing or curtain-wall firestops?
Can AFB replace safing or curtain-wall firestops?
No. AFB is a batt insulation for framed cavities. Joint safing, perimeter fire containment, and curtain-wall details require engineered firestopping systems tested for those joints.
How do I detail outlets for high STC?
How do I detail outlets for high STC?
Follow the tested partition or acoustician’s details—back-to-back boxes, putty pads, acoustical sealant, and limited penetrations often matter more than swapping insulation alone.