Rafters, it is

First of all, think about how much the material for the roof will weigh. As for the weight of natural tiles, it will be ten to fifteen times larger than the weight of the metal tile and five times soft tiles. If we talk about the foundation, then he must have a margin of strength. As for the rafters, it is recommended to be built only on the recommendation of the coating manufacturer for the roof. If you choose new roofing materials, you should know that their weight will greatly affect how much the cost of work will cost you. More heavier materials for the roof and will cost more too.