To limit the probability that the rain load used for the design of structural elements supporting roofs on which rain can accumulate will not take into account the maximum expected accumulation of rainwater on a catchment area of roof, which could lead to the excessive deformation of, or excessive stress in, structural elements, which could lead to damage to the building.
To limit the probability that the one-day rainfall value used will not be compatible with the geographic characteristics by directing Code users to Sentence 1.1.3.1.(1) [Appendix C], which could lead to the excessive deformation of, or excessive stress in, structural elements, which could lead to damage to the building.