3 in. thickness with NRC 1.10 / SAA 1.08 per ROCKWOOL USA AFB TDS
Key features
15.25 in. width class for 16 in. o.c. wood framing per manufacturer tables
Noncombustible stone wool for interior acoustical/fire-batt specifications
Technical specifications
| Thickness | 3.0 in |
|---|---|
| Width | 15.25 in |
| Length | 48.0 in |
| Coverage | 80.0 sq ft/pack |
| Material | Stone wool (mineral wool), ROCKWOOL AFB® |
| Fire rating | Noncombustible per ASTM E136 on ROCKWOOL USA AFB TDS; 0/0 ASTM E84 indices; rated walls require listed assembly documentation. |
| Sound rating | NRC 1.10 and SAA 1.08 at 3 in. nominal thickness per ROCKWOOL USA AFB TDS (11-2025); distributor pages may differ—use the PDF for code submittals. |
| Density | Nominal density >2.5 lb/ft³ per ASTM C167 on ROCKWOOL USA AFB TDS. |
| Framing width | 15.25 in. batt width aligned with 16 in. o.c. wood stud bays |
| Construction type | Interior wood-stud module (15.25 in. width class per ROCKWOOL USA AFB dimensional tables; verify 48 in. length on bag) |
| Application area | Interior wood-framed partitions and compatible interior wall/floor cavities where 3 in. AFB thickness and wood-stud width module match the specifier’s details. |
Product details
Wood-framed interior corridors, suite dividers, and podium-level partitions often specify mineral wool when the architect wants noncombustible cavity media inside a 16 in. o.c. wood module. The 15.25 in. batt width class exists because the clear distance between 2× studs at 16 in. on center is about 14-1/2 in.—and ROCKWOOL documents corresponding wood-stud batt widths on the USA AFB data sheet.
This SKU ships 3 in. thick for deeper acoustic and fire-cavity performance than 2 in. batts while still fitting many nominal 2×6 or furred assemblies depending on the gypsum board schedule. Always verify actual stud depth, service zone, and deflection details before assuming a three-inch batt belongs in every wood wall.
Acoustically, rely on the manufacturer’s published curve for 3 in. thickness: the 11-2025 USA AFB TDS assigns NRC 1.10 and SAA 1.08 to that row. Some distributor pages round or abbreviate; the PDF is the tie-breaker for submittals.
Fire language matches the rest of the AFB family: noncombustibility per ASTM E136 / CAN/ULC S114 statements on the sheet and 0/0 flame spread and smoke developed per ASTM E84. Pair those material facts with UL or Intertek listed assemblies when the drawing calls out a one- or two-hour partition.
IDI’s catalog page for the 3 × 15 × 48 configuration (supplier part 329432, SKU 1002756) documents 80 square feet per package; YEARS aligns coverage with that module.
Anchor your compliance package to https://p-cdn.rockwool.com/syssiteassets/o2-rockwool/documentation/technical-data-sheets/commercial/afb-acoustical-fire-batts-techdata.pdf and refresh downloads whenever ROCKWOOL re-issues the sheet.
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
Is the width 15 in. or 15-1/4 in.?
Is the width 15 in. or 15-1/4 in.?
ROCKWOOL’s USA AFB data sheet lists wood-stud batts as 15.25 in. wide (387 mm). IDI marketing copy sometimes rounds to 15 in.; use the manufacturer’s dimensional table and the master-pack label for field verification.
What NRC applies to 3 in. AFB?
What NRC applies to 3 in. AFB?
The ROCKWOOL USA AFB technical data sheet dated 11-2025 lists NRC 1.10 and SAA 1.08 on the 3 in. nominal thickness row.
Can I install this SKU in metal studs?
Can I install this SKU in metal studs?
This SKU’s width is in the wood-stud class. For 16 in. and 24 in. steel-stud modules, use the 16 in. × 48 in. or 24 in. × 48 in. AFB formats ROCKWOOL publishes instead of forcing an ill-fitting width.
Does AFB provide a thermal R-value for code compliance?
Does AFB provide a thermal R-value for code compliance?
AFB is marketed primarily for acoustics and noncombustible reaction to fire in interior partitions. The USA AFB data sheet emphasizes blanket insulation standards (ASTM C665/C553, CAN/ULC S702) rather than publishing an R-value table like thermal batts. Use Comfortbatt or project-specific calculations when thermal resistance drives design.