Which is better for exterior 2x6 walls?

The Owens Corning kraft-faced roll. Its built-in vapor retarder faces the warm side of an exterior wall, which is what code usually wants. The Knauf roll is unfaced and would need a separate vapor barrier.

Which is better between floors?

The Knauf unfaced roll. Interior floors do not need a vapor retarder, and an unfaced roll avoids trapping moisture. It is also GREENGUARD Gold certified.

Do they cover the same area?

Yes. Both cover 48.96 sq ft per roll at 15 in. wide and about 39 ft long, and both are R-19. Buy the same number of rolls for the same cavity.

Is the faced roll worth the extra cost?

If you are doing exterior walls, yes. It replaces a separate vapor barrier and installs faster. For interior walls, the unfaced Knauf roll is the better value.

Both are fiberglass and last the life of the wall if kept dry. Faced rolls can tear their kraft paper during install; unfaced rolls have no facing to damage.

Can I use the faced roll in an interior wall?

Not recommended. A vapor retarder inside an interior wall can trap moisture. Use the unfaced Knauf roll there instead.

INSULATION R19 KRFT15X93 vs Knauf R-19 Unfaced Fiberglass Insulation Roll

Both are R-19 fiberglass rolls sized 15 in. x 39 ft. covering 48.96 sq ft, so the choice comes down to facing and price. The Owens Corning roll is kraft-faced with a built-in vapor retarder, which suits exterior 2x6 walls. The Knauf roll is unfaced and GREENGUARD Gold certified, which suits interior walls and between floors where no vapor barrier is wanted. Check the latest prices on both before buying; the two are close in cost at most stores.

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