Which type of loads is live load reduction NOT applied to?

Live load reduction is a design practice used in structural engineering to account for the fact that not all live loads (temporary loads such as occupancy, furniture, or vehicles) are likely to be applied to a structure at the same time or at their maximum potential. This reduction is typically applied to floor live loads due to expected usage patterns, where only a portion of the load is considered to be acting simultaneously.

However, for roof live loads, live load reduction is generally not applied. This is because roof areas are subject to specific and relatively predictable loads, such as snow, rain, and maintenance activities, which are more uniformly distributed across the entire surface. As a result, the design does not allow for significant reduction, since it assumes that the full live load could realistically be applied at once to a roof structure. This ensures safety and structural integrity, particularly since roof loads can also be heavily impacted by environmental factors that require full consideration during design.

In summary, live load reduction is not applied to roof live loads because these loads are more consistent and predictable in their application compared to floor live loads, where the distribution and timing of occupancy can allow for a reduction factor.