Pejtsik cello sheet
Exterior wall construction can be classified by its fire-resistance. A fire-resistive rating is the time that exterior wall construction can withstand fire exposure as determined by a standard fire test. Wall construction can be classified as 4-hour, 3-hour, 2-hour, 1-hour and non-rated construction. USG Sheetrock Brand Mold Tough Fire Code X USG Sheetrock Brand Mold Tough Fire Code X Gypsum Panels have a noncombustible fire- and moisture-resistant gypsum core encased in moisture and mold-resistant 100-percent recycled green face and brown back paper. They score and snap easily installing and finishing as easily as standard drywall.