The rafter is a part of the supporting system of the pitched roof, which is not used in a single copy, but is used as a rafter structure. This part consists of vertical racks, inclined rafter legs and inclined struts. If necessary, the rafters are strengthened along the bottom to the rafters.
What is a rafter
The rafter is an element that underlies the whole system, it consists of inclined struts, inclined rafter legs and vertical racks. Reliance is carried out in wooden chopped buildings on the crowns. But if we are talking about frame buildings, then leaning is done on a strapping from above, while in stone houses they are installed on a Mauerlat, which is a bar with a maximum thickness of 160 mm. Mauerlat can be located along the length of the building, or just under the rafter's foot. In the case when the rafter leg has a section of small width, the elements sag over time. In order to exclude this phenomenon, it is necessary to use a lattice, which includes struts, racks and crossbars.
For struts and crossbars, boards are used, the width of which can be 150 mm, while the thickness is 25 mm. To fix the rafter legs, a puff is used that ties the lower parts of the rafter legs. When sliding on a tightening, the end of the element may break the integrity. In order to exclude sliding, the rafter foot must be strengthened with a puff by the cutting method. Rafters should be 400 mm from the edge.
Need to use
All this is used to give the roof a quality of stability under the influence of high loads. As a result, the roof acquires the properties of reliability, and the rafters transfer the load from the weight of the entire system and snow to the internal supports of the building. If the building has small spans, then you must use layered rafters. If there are no intermediate supports, then the design of hanging rafters should be involved.
Where rafters are used
The rafter is an element that is part of one large system for hardening the roof. Depending on what design features the roof will have, different rafter systems are used. In modern construction, rafters and roofing systems as a whole have certain requirements, among them:
- practicality;
- low installation and manufacturing costs;
- durability;
- strength;
- ease of installation;
- functionality; aesthetics.
The rafter is an element that can be used in the construction of single-pitched, double-pitched and broken roofs. These elements are also present in the roof of Sudeikin. In the first case, rafters in the form of beams are used, their support is carried out on the walls, quite often this allows the roof to be operated. The roof structure in this case should be pre-designed, the only way to distribute the load on the roof used. The rafter, the meaning of which is mentioned in the article, can also be used in a gable roof, in this case the system has triangular trusses that are located at a certain angle. The legs should be on the Mauerlat, while they are additionally equipped with crossbars and stretch marks.
If there is a desire to leave space for the attic, then a sloping roof should be made, the rafter system of which will be more complex. In this case, several types of rafters are used at once. It is worth noting that the construction of the Sudeikin roof is very original and attractive. In this case, the rafters are interconnected, forming four triangular slopes. Such a system is suitable for square tasks.
What is a rafter in terms of design features
You can independently carry out the construction of the roof. Rafters in its composition can be inclined. In this case, the upper node is fixed using a hinge, and the lower one through a floating connection. Such constructions of rafters in the form of profile systems are usually called indispensable. This system does not transfer the load to the Mauerlat. The ridge connection is carried out as rigidly as possible, the support on the Mauerlat is using a hinge. In this case, parting forces are transmitted to the walls. This system, which combines hanging and layered rafters, is also called a hybrid. Redistribution of load is the main principle of this system. The weight of the roof is taken by the rafters with legs that are butt-joined and work on a bend. At the same time, the ridge beam is not such a mandatory element, since it is almost inactive.
For reference
Spacer rafters, the photos of which are presented in the article, should be equipped taking into account the quality of bolted joints. First, holes should be drilled in the products, the diameter of which should be one millimeter smaller than the diameter of the bolt or stud. If they are excessively large, damage to the Mauerlat may occur during the process.
Material selection
The word rafters is known today to every builder, but not every home master is familiar with what is the best material to use for the manufacture of these elements in the roof structure. It may be based on wood, monolithic reinforced concrete structures or metal. The latter are galvanized steel or, in the first case, it is possible to obtain lightweight structures. When choosing a material, experts advise paying attention to the purpose of the building. In this case, the estimated load on the roof should be taken into account. Wooden rafters are used most often, for this a high-quality glued beam or solid wood is selected. For work, you will need not only lumber, but also carpentry tools, as well as fasteners. If you decide to use glued beam, then it should have a width ranging from 12 to 18 m, but solid logs and boards can have any design.