During the construction of any building, various types of work are performed, while the correct implementation of each stage is the key to obtaining a quality result. So, during the construction of the roof, the installation of truss systems occupies an important place. In this case, many points must be taken into account, such as calculating the pitch of the rafters, the angle of inclination, and so on.
Hipped roof truss system
Hipped-type roofing is performed with a four-pitched truss system, while all sides (hips) of the roof are isosceles triangles. The design consists of four hips, slightly different in geometric shapes (the ends of the roof are triangles, and the transverse sides are in the form of trapezoids).
Installation of truss systems of this type is carried out using the following elements:
- Slanted (diagonal) rafters - these elements are sent to the corners of the building.
- Narozhniki - shortened carriersdetails. They are attached at one end to the Mauerlat, and at the other - to the braided elements.
- Struts and racks.
- Crossbar (to strengthen the structure in case of spacer pressure).
- Reclining - support for racks and struts.
- Sprengel - additional support for long spans.
- Run - a beam that is installed parallel to the Mauerlat (extreme support for rafters).
It should also be noted that there are two types of hip roof rafter systems, which differ in the type of execution:
- Hanging design. Installation of rafter systems of this type is carried out in the absence of walls inside the structure.
- Layer system. This design is used in the presence of an average load-bearing partition, or columnar supports are provided in the gaps when laying the foundation of a reinforced concrete building.
System calculation
Installation of truss systems must be carried out with a preliminary calculation of structural elements. At the same time, the main points are highlighted:
- The pitch of the lathing bars depends on what material the roof is made of: for metal tiles it is 35-40 cm, for steel sheets - 25 cm, cement-sand tiles - 37.5 cm.
- The calculation of the length of the rafter legs and other fixing supports is carried out depending on the angle of the roof. This value is taken according to established standards (SNiP). It depends on the amount of precipitation, wind loads and roofing materials used.
- The location and type of supports for diagonal rafters is provided depending on the span. So, with a length of up to 7.5 m, struts or racks are made, which are attached to the upper part of the sloping elements. And with a span of more than 9 m, sprengels and racks can also be used.
Installation work order
Installation instructions for a truss system of four slopes, if you select only the main points, will look like this:
- Installing the Mauerlat on the walls, when laying, a special recess can be provided or special fasteners are installed to prevent horizontal shift. Before that, you need to check the geometry of the walls.
- Installation of rafters. They begin this work with opposite elements, they are attached to the Mauerlat by means of sprengels. At the same time, for a quality connection, trimming is performed on the rafters on both sides.
- Narozhniki are attached to the rafters through tiled beams. Corner parts are performed parallel to the central elements.
- To increase strength, trusses with uprights are provided at the corners or a transverse beam is installed that connects the central rafters. It is attached with several racks.
Such work as the installation of a truss system (the price will be significantly reduced) can be done independently. Of course, this requires construction skills and some engineering knowledge.
