R-30 at 7.25 in. for wood 16 OC module (15.25 in. × 47 in.) per USA TDS (05-2025)
Key features
Semi-rigid batts with flexible long edges for cavity contact
Noncombustible stone wool; 0/0 ASTM E84 per manufacturer TDS
Technical specifications
| R-Value | 30.0 |
|---|---|
| Thickness | 7.25 in |
| Width | 15.25 in |
| Length | 47.0 in |
| Coverage | 29.86 sq ft/pack |
| Material | Stone wool (basalt and recycled steel slag) |
| Fire rating | Noncombustible per ASTM E136; Flame Spread 0 / Smoke Developed 0 per ASTM E84 on ROCKWOOL USA Comfortbatt TDS (05-2025). |
| Sound rating | Thick stone wool improves cavity damping versus minimum fills; STC/NIC still require assembly design and perimeter seals. |
| Density | >1.8 lb/ft³ per ASTM C167 on ROCKWOOL USA Comfortbatt TDS (05-2025). |
| Framing width | 16" OC |
| Construction type | Wood stud framing |
| Application area | Attic and cathedral ceilings, high-R exterior wood walls, and exposed floors per ROCKWOOL when 7.25 in. thickness and the 15.25 in. × 47 in. module fit the cavity. |
Product details
Prescriptive tables keep pushing attic and roof targets upward while structural depth does not always grow in lockstep. A 7.25 in. Comfortbatt layer gives teams stone wool in the 15.25 in. × 47 in. wood module ROCKWOOL prints for 16 in. o.c. studs on the USA sheet dated 05-2025, labeled R-30 at that thickness in the wood-stud thermal table.
SKU 291369 is the distributor-facing pack for that geometry; expect about 29.86 sq ft per bag under YEARS data and verify counts on delivery tickets.
Flexible long edges are meant to compress on insertion and recover against stud faces—gains disappear when batts are face-compressed behind utilities, left floating at corners, or sliced without restoring full thickness.
Fire reaction language on the Comfortbatt TDS includes ASTM E136 noncombustible and ASTM E84 0/0 indices; California State Fire Marshal listings and GREENGUARD Gold marketing appear in ROCKWOOL literature—refresh submittals when listings change.
Moisture and fungi statements on the sheet support durability narratives, but they do not replace vented attics, controlled interior humidity, or correct vapor detailing at the ceiling plane.
Anchor compliance to https://www.rockwool.com/siteassets/o2-rockwool/documentation/technical-data-sheets/residential/comfortbatt-exterior-wood-and-steel-stud-thermal-batt-insulation-techdata-us.pdf (05-2025) and cross-check accessory details at https://www.rockwool.com/north-america/products-and-applications/products/comfortbatt.
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 compliant, ASTM E136 noncombustible, ASTM E84 flame spread 0 / smoke developed 0 (Note 1 Class A per IBC on TDS), ASTM C518 thermal resistance per published R-thickness table, GREENGUARD Gold per ROCKWOOL Comfortbatt marketing
Frequently asked questions
Is this batt for 2×4 exterior walls?
Is this batt for 2×4 exterior walls?
No. 7.25 in. Comfortbatt R-30 is for deep cavities where that thickness fits—attics, cathedral ceilings, and compatible wood framing per ROCKWOOL—not 3.5 in. 2×4 stud bays.
What stud spacing does 15.25 in. width match?
What stud spacing does 15.25 in. width match?
The 15.25 in. × 47 in. module aligns with nominal 16 in. on-center wood framing per the USA Comfortbatt wood-stud table; do not substitute into 24 in. o.c. bays without verifying width.
How many square feet per bag?
How many square feet per bag?
YEARS lists about 29.86 sq ft per package; confirm on the product label before reconciling purchase orders.
Where do R-values come from?
Where do R-values come from?
Published R-30 at 7.25 in. for this module is taken from ROCKWOOL’s USA Comfortbatt TDS (05-2025) wood-stud thermal table; cite that sheet on code submittals.