Which practice helps prevent chipping during finishing around openings?

• A. To increase roughness around openings.
• B. To accelerate curing.
• C. To establish a clean edge and reduce chipping during subsequent finishing steps.
• D. To hide imperfections by applying a sealant.

Answer: (C)

Establishing a clean, defined edge around openings creates a protected boundary that resists damage as you continue finishing work. When the edge is crisp and well-defined, the finishing tools don’t catch and pull away brittle concrete at the opening, which is the main cause of chipping. This upfront control of the edge helps the subsequent finishing steps go smoothly and maintains a smooth, intact transition around the opening.

Increasing roughness around openings would make the edge more susceptible to chipping. Accelerating curing doesn’t address edge quality and can affect strengths and surface texture. Hiding imperfections with a sealant doesn’t prevent the actual edge from chipping and can interfere with bonding of finishes.