What is the minimum length of drywall screw for attaching 1/2-inch gypsum board to wood studs?

What is the minimum length of drywall screw for attaching 1/2-inch gypsum board to wood studs?

• A. 1 1/4 inches
• B. 1 1/8 inches
• C. 2 inches
• D. 3/4 inch

Answer: (B)

The essential idea is that drywall screws must go through the drywall and into the stud by a solid amount to hold properly. For 1/2-inch gypsum board, you should penetrate the stud by about 5/8 inch. That means the screw needs to be long enough to pass through the 1/2" board plus at least 5/8" into the wood, totaling 1 1/8 inches. So 1 1/8 inches is the minimum length that ensures adequate embedment; shorter screws won’t reach far enough into the stud, while longer ones are not required for the minimum but would still work.

The essential idea is that drywall screws must go through the drywall and into the stud by a solid amount to hold properly. For 1/2-inch gypsum board, you should penetrate the stud by about 5/8 inch. That means the screw needs to be long enough to pass through the 1/2" board plus at least 5/8" into the wood, totaling 1 1/8 inches. So 1 1/8 inches is the minimum length that ensures adequate embedment; shorter screws won’t reach far enough into the stud, while longer ones are not required for the minimum but would still work.