Best stone wool insulation batts and boards
Researched by Deal.ai's shopping agent across stores on November 7, 2026. Prices below are today's.
Top pick: ROCKWOOL ComfortBatt R-15 (3.5 in x 15-1/4 in x 47 in) — the everyday batt for 2x4 stud walls and joist bays. It friction-fits between framing, cuts with a serrated blade, and stone wool adds fire resistance and sound damping that fiberglass doesn't match.
Who the others suit:
- ComfortBatt R-30 (7-1/4 in) — attics and 2x8 ceiling joists where you need the higher R-value.
- Safe'n'Sound (3 in) — interior walls and floors between rooms; it's the sound-control batt, not a thermal one.
- ComfortBoard 80 (rigid) — exterior continuous insulation, basement walls and anywhere you need a board that holds its shape.
- Rockboard / 1–2 in mineral wool boards — acoustic panels, around ducts, and tight spots where batts won't go.
Check the R-value and thickness against your cavity depth before ordering.
