According to NRCA guidance, what gauge or heavier should steel panel roof decks be?

• A. 18 gauge or heavier
• B. 22 gauge or heavier
• C. 24 gauge or heavier
• D. 20 gauge or heavier

Answer: (B)

Steel deck thickness matters because it governs structural stiffness, fastener performance, and long-term durability of the roof system. In metal roofing terms, gauge numbers work opposite to thickness: the smaller the number, the thicker the metal. NRCA specifies that steel panel roof decks should be at least 22 gauge, or heavier. This minimum ensures the deck is stiff enough to resist deflection under loads, provides solid footing for fasteners, and supports the roofing assembly without excessive flex or pullout. Options thinner than that, like 24 gauge, don’t meet the standard. While thicker decks such as 20 or 18 gauge are acceptable, the stated minimum remains 22 gauge or heavier.