Cornerite for reinforcing internal angles over lath must be:

Cornerite for reinforcing internal angles over lath must be:

• A. 1.75 psi
• B. No. 19 wire fabric with 2 inch legs
• C. Wood angle strip
• D. Plastic corner bead

Answer: (B)

Reinforcing internal corners over lath calls for a dedicated corner reinforcement that integrates with the plaster and provides tensile strength at the bend. Cornerite is a wired fabric that is embedded into the plaster at the corner, then the legs extend onto each wall surface. Using No. 19 wire fabric with 2-inch legs gives enough embedment on both sides to grip the plaster and prevent cracking from movement or shrinkage, making it the standard and most effective option for interior corners over lath. The other choices aren’t suitable here. A psi rating isn’t a reinforcement device. Wood angle strips can warp, shrink, and don’t bond well with plaster over lath, making cracks more likely. Plastic corner beads exist for other systems but don’t provide the same cross-face reinforcement at internal corners over lath that cornerite with wire fabric does.

Reinforcing internal corners over lath calls for a dedicated corner reinforcement that integrates with the plaster and provides tensile strength at the bend. Cornerite is a wired fabric that is embedded into the plaster at the corner, then the legs extend onto each wall surface. Using No. 19 wire fabric with 2-inch legs gives enough embedment on both sides to grip the plaster and prevent cracking from movement or shrinkage, making it the standard and most effective option for interior corners over lath.

The other choices aren’t suitable here. A psi rating isn’t a reinforcement device. Wood angle strips can warp, shrink, and don’t bond well with plaster over lath, making cracks more likely. Plastic corner beads exist for other systems but don’t provide the same cross-face reinforcement at internal corners over lath that cornerite with wire fabric does.