The main and bearing part of roof design are rafters. Their correct fixing will allow to distribute evenly loading and to hold roof on the place at wind gusts. For connection of different elements of rafter design there are receptions and rules.
- - Wooden bars;
- - antiseptic solution;
- - hacksaw;
- - construction level;
- - tape measure;
- - metal plates;
- - metal corners;
- - bolts;
- - pins with thread;
- - washers.
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1. Choosing the section of rafters, be guided by design of specific roof and bay length. As a rule, thickness of rafter is not less than five, and width – fifteen centimeters. Wood of which they are made should not be absolutely wet and too dry as the tree can be deformed. Surely before mounting process rafters special antiseptic solution.
2. The prepared notched rafters need to be stacked on several points. For creation of the top point at necessary height expose ridge board on level. The lower point – inferior purlin. For midpoint make to the necessary level chair or temporary prop under slope of roof or under several rafters. In difference of chair and inferior purlin which will remain in design the temporary props and ridge board can be withdrawn after fixing of rafters. If the roof design allows, it is possible to join rafters from opposite slopes at once, without construction of ridge board.
3. Extensions, chairs and drag struts can be done as after mounting of all rafters, and at once. In some designs ready farms are established. The farm consists of rafters, drag struts and extensions and gathers on template. All elements are strongly fastened among themselves, and then in assembled form are mounted on roof.
4. Fastenings of rafters have to be carried out reliably and qualitatively. It is impossible to use linings which are deformed over time. It is important that the adherence of zapil was dense and exact. To fix rafters to chairs, chairs, inferior purlin, extensions and among themselves it is necessary by means of special brackets, corners, pins with thread, bolts and metal plates.
5. When fastening slung bolts and nuts use of washers or plates from metal is obligatory. It will prevent their drowning in wood. Nails can be used only for temporary fastening during mounting. Subsequently they need to be replaced with special fastening elements. When building rafters in length carry out connection with an overlap. At the same time impose rafters not less than on meter and twist at least two bolts.
6. For fastening of rafters in the lower point it is necessary to notch "saddles" which have to provide dense adherence of rafters on inferior purlin. If on all slopes roof corner identical, make template and on it carry out has washed down on all rafters. Notch not more deeply, than on quarter of width slung. On the lower and average points carry out fastening of rafters special metal corners. On the fad connect rafters end-to-end and among themselves fix them by metal plates.