Expansion joints in plastered walls are installed to?

• A. Accommodate movement and prevent uncontrolled cracking
• B. Provide a decorative feature
• C. Improve sound insulation
• D. Prevent paint from adhering

Answer: (B)

Expansion joints are installed to accommodate movement in plastered walls, allowing the plaster and underlying substrate to expand and contract with temperature changes, humidity, and structural shifts without developing uncontrolled cracks. By providing a deliberate place for movement, stresses are relieved and cracks form along the joint rather than across the surface, keeping the wall durable and visually intact. They aren’t meant to be decorative features, nor are they primarily for sound insulation or paint adhesion purposes. The goal is to manage movement in a controlled way.