R-15 Kraft-faced insulation is formaldehyde free fiber glass insulation protected on 1 side with moisture resistant Kraft facing. R-15 Kraft-faced batts come in pre-cut lengths for insulating standard 8 ft. wall cavities. R-15 batts are perfect for insulating exterior 23 in., 2 in. x 4 in. walls where moisture control is required. 1 bag covers 103.97 sq. ft.