Red Seal Lather (Interior Systems Mechanic) Practice Exam

What is the purpose of a corner bead?

1. To add decorative elements to corners

2. To provide a clean and durable edge at outside corners

3. To strengthen the structural integrity of walls

4. To help with electrical wiring installation

The correct answer is: To provide a clean and durable edge at outside corners

The purpose of a corner bead is primarily to provide a clean and durable edge at outside corners. When drywall is installed, the raw edges of the drywall can be prone to chipping and damage over time, especially at exterior corners where they are more exposed to wear and impact. Corner beads are typically made from metal or PVC and are installed over the joint between two pieces of drywall at the corner. This not only reinforces the corner against impacts but also creates a straight, sharp edge that can be effectively finished with joint compound for a smooth appearance. This clean and durable finish helps ensure that corners maintain their integrity throughout the life of the wall. Additionally, by creating a defined edge, corner beads facilitate easier finishing and painting, contributing to the overall aesthetics of the interior space.