The process of installing the roof truss system begins with the preparatory work. Reliability and appearance of the roof depends on the quality of the installation of rafters.
The device rafters chetyrehskatnoy roof.
The roof trussing system provides for the preparation of the walls and ceilings of the house. This will require measuring the walls and angles. If necessary, level the surface. For a brick house use cement-sand screed, for a wooden building - special gaskets. The installation of the truss system involves the use of the following materials and tools: nails, hammer, screwdriver, leveling mixes, brushes, bars, roofing material, level.
For waterproofing works, special material is required. On it installation of a power plate is made. It allows you to fix indirect angles around the perimeter of the entire house. The Mauerlat, raised to the top of the wall, is not the basis for the expansion structure.
Features of mounting a truss system.
The truss system consists of the following elements:
Arrangement of the overhang is performed using additional rafters. The last elements are presented in the form of bars with a section of 50x20 mm. Parameters vary according to climatic conditions. To calculate the cross-section of the beam, you need to find out:
Builders are advised to select a material for arranging the truss system so that the load indicator does not exceed 50 kg per 1 m². An important factor in the installation of the considered structure is the snow load. This indicator can be calculated using a special formula:
F = P * k, where F is the snow load, P is the weight of snow per 1 m², k is the correction factor.
To calculate the wind load on the cover, the following formula is used:
V = R * k, where V is wind load, R is an indicator of the corresponding region, k is a correction factor.
The truss system of the mansard roof.
The rafter system is mounted subject to the accuracy of the calculations. On the roof raise 2 beams using rafter scaffolding. The ends of the truss legs will need incision. This is necessary to give a stable position to the rafters on the mauerlate. At the same time rafter legs mark that it was possible to be guided easily in their site.
Bottom ends are fixed in a similar way. This will connect the rafters together, forming an overlap. Then the elements are fastened with nails. After installation, the lower ends are fixed. Bars cut out on 1/2 of their thickness.
The remaining pairs of rafters are prepared on the ground. To do this, use the template. The next step involves the installation of bars from 2 sides of the gable part of the wall. Rafters are attached to the mauerlat with nails. Level control and horizontal installation of the installation provide for tensioning the cord between 2 installed pairs of rafters. In some cases, adjust the height of the mounted pairs. To do this, you need to put a small plank of the appropriate height under the bars.
The construction step equals 70 cm. This parameter can be controlled with the help of the board on which the step is applied. She nailed to the top of the left and right rafter legs. If there is a big step, then you will need to further strengthen the structure. To do this, use horizontal bars - tightening. In such a situation, the trusses are connected by a horizontal board in the place of the ridge. A similar method forms the corresponding node.
Tightening for a truss system is performed from boards interconnected. Each board is trimmed to the desired length. For fixing use nails, nuts and studs with rafters.
To prevent pulling down, you will need to connect it to the ridge.
The next step involves the production of curtain rails. Rafters with insufficient length for arranging the overhangs are built up artificially. To do this, use the board-filly. The length of one board should be more than 40 cm. Builders recommend using boards of 60 cm in length for this purpose. Its width may be less than the width of the rafters.
The filler is fastened to the rafters with nails. At the same time, a certain clearance is observed. To fill it, you need a liner. If the eaves overhangs are installed, the rafters are finally attached to the power plate. To do this, use the metal strip, which is wrapped on the right and left truss legs. The strip is attached to the structure with nails or screws whose depth is 30 cm.This technology prevents a possible breakdown of the roof in bad weather. The strip can be replaced with steel wire, the thickness of which exceeds 6 mm.
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