What is the purpose of roof joists?

The purpose of roof joists is to support roofing sheets and loads, making them crucial structural components in building construction. Roof joists are horizontal members that span the space between supporting walls or beams, thereby distributing the weight of the roofing material and any additional loads, such as snow, rain, or equipment, to the underlying structure. They help prevent sagging and maintain the integrity of the roof, ensuring that it can withstand various environmental stresses over time.

The other options present concepts that do not align with the primary function of joists. Decorative features, insulation, and aesthetic considerations, while they may be components of roofing design, are not the fundamental roles of roof joists. Their main purpose remains firmly rooted in structural support, which is critical for the overall safety and durability of the roof system.