The roof of the building in its design is almost never flat due to its functional features, most often it is either straight and with an inclination, or gable – consists of two planes connected at a certain angle with respect to the joint.
The rafters, in fact, hold the entire roof structure, determining its strength, inclination and other characteristics. The main material for creating rafters is a tree when metal is used for such purposes, then welded frames are already used.
The installation of the rafter system itself depends on the design of the roof, as well as on its size. The rafters can be installed directly on the walls of the house so that the additional support is located in the middle, and they can rest on each other on the skate, as if hanging around the perimeter of the entire rafter system. The latter option is most often used for arranging attic and overall rooms located under the roof, while direct fixation of the rafters to the walls is applicable for structures, in which the distance does not exceed six meters between the supports.
The most difficult part of the work on the creation of the rafter system of the roof, oddly enough, is precisely the measurements, because the effectiveness of the entire installation will depend on the accuracy of this procedure. If only one detail is incorrectly measured, then you can ruin the entire structure.