Roof Structural Elements, Device

2023 Author: Philip Bishop | [email protected]. Last modified: 2023-08-25 07:54

The elements of the roof are rafters, lathing and fencing, that is, the roof.

Slopes and edges are sloped surfaces. The horizontal components include the ridge, the valley and the gutter. In order to organize a drain at the lower edge of the slope, in some cases, gutters are used. The lower part of the slope, located between the groove and the edge, is called the descent. You can call it the main element of the roof.

The wooden roof frame is represented by the following structural elements: basic and mandatory - Mauerlats, rafters and battens, as well as auxiliary ones - a tightening, a strut and struts.

Mauerlat, popularly called "uterus", "matitsa", is a bar with a cross section of at least 10 x 10 cm or a log hewn from the bottom side. The Mauerlat should be a support for the rafters, and its function is to evenly distribute the load on the outer walls. On walls made of lightweight masonry, lightweight concrete, frame and panel, a continuous Mauerlat should be laid along their entire length.

If the walls are massive, made of stone or brick, then under each rafter leg it is necessary to put a piece of timber or logs with a length of 0.5 m. In this case, the ends of the clamps are attached to metal hooks, when laying the walls, they are embedded in 2-3 rows of bricks.

Rafters made of wooden beams, boards, bars are essentially the supporting frame of the roof, its foundation.

In addition, rafters are a supporting structure that can withstand the weight of the roof, snow and wind pressure. That is why the wood used for the manufacture of rafters must be devoid of any flaws: wormholes, knots, rot, cracks in the connection zones and outside of them, more than 0.25 of the length of the beam and a depth of more than 0.25 of its thickness.

For the manufacture of rafters, coniferous boards with a thickness of 40-60 mm, or beams, are suitable. The lumber should be free from defects, well dried, with a minimum number of knots. It is allowed to use logs, but it should be borne in mind that they are much heavier.

Plank rafters are characterized by ease of assembly, since all connections are made on nails with or without inserts and linings. The cuts that weaken the timber and log structures, in this case, are used only to connect the racks with the girder and lie in the inclined rafters.

Rafters section

Due to a number of factors such as:

• load caused by the weight of the roof and snow;
• rafter step; span size;
• roof slope.

The size of the section of the rafters must be selected taking into account their length and the distance between them.

You can attach the rafters directly to the Mauerlat. However, in the case when it is necessary to close a large span, only the basic elements of the frame will not be enough.

In such a situation, tightening, stance and braces will help, both all together and separately.

It is important to consider that in any roof structure there are two main components: the enclosing, represented by the roof, and the load-bearing, or rafters, which are divided into hanging and layered.

A characteristic feature of layered rafter systems is their durability, due to operation under through ventilation, which prevents possible rotting of wooden layered rafters and their failure. The relative simplicity of the device and implementation also play an important role.

The layered rafter system consists of the following structural elements:

• rafter leg;
• rafter elements;
• lathing (flooring).

The pitched roof rafter system includes separate rafters, resting their edges on the opposite walls of the structure. In the case of a gable roof, the rafter system consists of a pair of inclined rafter legs, which abut the lower edges against the walls, and the upper edges against the girder, which is supported by uprights.