Is stone wool better than fiberglass for soundproofing?

Yes, in most interior walls. Its higher density blocks more airborne noise than fiberglass batts of the same thickness, which is why owners report quieter rooms.

Does Comfortbatt need a vapor barrier?

Follow local code and your wall assembly. Stone wool tolerates moisture, but most cold-climate walls still call for a vapor retarder on the warm side.

Can I cut it with a utility knife?

A serrated blade or insulation saw works best. Compress the batt and cut against a straight edge for clean edges that fit the stud bay.

Is it fire resistant?

Stone wool is noncombustible and withstands temperatures above 1,000°F, so it does not add fuel to a wall assembly. Check the assembly's fire rating with your builder.

Why is only one store listing it?

Comfortbatt is often sold through lumber yards and building suppliers rather than big-box listings. Ring's End had it at $89.99 as of November 7, 2026.

When is the price lowest?

Insulation prices tend to dip in fall and winter, outside the spring building season. With one store listing it, watch for yard sales and contractor pricing.

Where can I buy the ROCKWOOL Comfortbatt Stone Wool Insulation?

4 stores we checked sell it, including Ring's End, Arnold Lumber, Home Depot, Kamco Supply Corp. of Boston.

ROCKWOOL Comfortbatt Stone Wool Insulation

Q: Where is the ROCKWOOL Comfortbatt Stone Wool Insulation cheapest?

At Ring's End, for $89.99, as of our latest check.

Best price now

$89.99at Ring's EndObserved at 12:27 PM

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Our take on the ROCKWOOL Comfortbatt Stone Wool Insulation

ROCKWOOL Comfortbatt is stone wool batt insulation for walls, floors and ceilings, sold in blanket form. It resists fire, dampens sound and holds its shape in cavities better than loose fiberglass. It is GREENGUARD certified for low emissions. The best new price is $89.99 at Ring's End as of November 7, 2026, with only one store listing it new, so there is no recent price range to compare against.