A.Paul Fisette responds: When it comes to using unusual materials, most building inspectors will require a qualified engineer to review the plans, calculate the loads, size the rafters, and stamp the plans. However, as long as you’re aware of these requirements, the process of calculating dead loads is not that difficult.
Dead loads are simply the sum of the weights of all the building materials used to build a particular part of a structure. For example, the dead load of the roof might include the weight of the rafters, sheathing, roof covering, and anything else that is permanently attached to the roof structure, such as drywall on a cathedral ceiling. You need...
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