Strip reinforcement for continuous joints of gypsum lath and joints of dissimilar materials must be at least ___ wide.

Strip reinforcement for continuous joints of gypsum lath and joints of dissimilar materials must be at least ___ wide.

• A. 2 inches
• B. 3 inches
• C. 4 inches
• D. 6 inches

Answer: (B)

Reinforcing joints across gypsum lath and where different materials meet is about controlling cracks by giving the plaster a continuous, strong path to grip. A strip of reinforcement laid over the joint acts as a bridge, tying the adjacent surfaces together so the plaster can anchor into solid material and distribute stresses rather than cracking right at the joint. The minimum width for this strip is 3 inches, which provides enough surface area to grab the plaster and ensure proper anchorage on both sides of the joint. A narrower strip wouldn’t offer sufficient coverage or grip, while a wider strip isn’t required for typical installations and adds unnecessary cost.

Reinforcing joints across gypsum lath and where different materials meet is about controlling cracks by giving the plaster a continuous, strong path to grip. A strip of reinforcement laid over the joint acts as a bridge, tying the adjacent surfaces together so the plaster can anchor into solid material and distribute stresses rather than cracking right at the joint. The minimum width for this strip is 3 inches, which provides enough surface area to grab the plaster and ensure proper anchorage on both sides of the joint. A narrower strip wouldn’t offer sufficient coverage or grip, while a wider strip isn’t required for typical installations and adds unnecessary cost.