What is a requirement for copings on parapet walls?

For copings on parapet walls, the requirement for them to be non-combustible and weatherproof is crucial. This ensures that the coping material will effectively protect the parapet wall's top from water infiltration, which could cause structural degradation over time. Non-combustible materials are essential in preventing fire hazards, particularly in buildings where the risk of fire might be a concern.

Weatherproofing is equally significant, as it helps to prevent moisture and environmental damage, extending the lifespan of the parapet walls. Properly functioning copings will also help in directing water away from the building, thus preventing leakage and potential damage to the interior spaces.

The other choices do not universally apply to the requirements for copings on parapet walls. For instance, while some might choose metal for its durability, it is not a specification across all building codes or designs. The thickness of the coping is also not universally mandated to be greater than the wall itself, and there are no restrictions that limit the installation of copings to flat roofs only; they can be beneficial on various roof types.