Metal crate - roof elements and installation
The question of proper design and installation of the roof is a matter of principle for developers, because it is the first barrier separating a person’s dwelling from the environment and its adverse phenomena. The pledge of strength and high bearing capacity of the structure is considered to be a well-calculated roof system consisting of a set of interrelated supporting elements. Functions on the distribution of the weight of the roofing pie to a greater extent fall on the crate to which the waterproofing coating is attached. This essential element of the frame allows the ramps to keep their shape and carry intense snow loads. In this article we will tell you how the metal batten is different from the wooden one, and in what cases it is used.
Device and functions
The crate of the metal profile is a special flooring installed on the rafter legs of the roof frame. It represents steel corners, pipes of round or square section, fixed perpendicular to rafters with a certain interval. The installation of such a flooring is necessary, as it performs the following functions:
- Evenly distributes the weight of the roofing pie between the rafters. The weight of the roofing alone can be about 50 kg / m2, so it needs additional support especially in the winter, when snow is added to the permanent loads on the roof.
- Will come tough form stingrays. Some modern roofing materials (ondulin, shingles, roofing membranes) are resilient to varying degrees and are not capable of keeping their own shape, therefore it is necessary to make a wooden or metal crate for their flooring.
- Serves as a basis for fixing roofing material. The batten, the slats of which are installed with the same pitch, allows you to securely and accurately fix the roofing, and also significantly speeds up this process.
- Strengthens a rafter framework in especially vulnerable places. In places where there is a lot of weight (valleys, attachment points for snow holders and gutters), additional battens of the batten increase rigidity and bearing capacity of the structure.
Note! The design and material from which you want to make a crate for the roof depends on the slope of the structure, the weight of the performance characteristics of the roofing, as well as the climatic conditions of the region where construction takes place.
Kinds
Depending on the weight of the roofing, the slope of the roof, and the weather conditions, the design of the rafter frame may vary. In particular, the metal crate is constructed in accordance with the calculation of the maximum loads that fall on it during operation. There are several types of crates:
- Grid. Plain or latticed lathing for the roof is a flooring of the corners or hollow metal profile, laid perpendicular to the rafters, with a step of 25-45 cm. This design is suitable for mounting most sheet roofing materials, as it has high strength and load-bearing capacity.
- Solid. A continuous crate is called flooring of battens, laid at a distance of no more than 1 cm between each other. Such a construction is mounted if the roofing material used to overlap the roof does not have its own rigidity or has an impressive weight, that is, for the installation of ceramic tiles, shingles and other roll coverings.
- Sparse. Sparse crate is a design with an increased distance between the elements. Its pitch can be more than 50 cm. This variant of the roofing lathing is used to install rigid waterproofing materials, for example, slate in order to reduce the weight of the roofing pie and the load on the supporting walls of the structure.
Please note! The smaller the slope of the slopes, the flatter the roof, the more the load falls on it, because snow, melt and rain moisture accumulate on it. Therefore, such roofing structures need a more reliable crate with a reduced distance between the elements.
Virtues
Previously, in private house construction, the most common material from which the crate was most often made was wood. This lightweight, inexpensive and ubiquitous material did an excellent job with the functions assigned to it. However, recently it began to be replaced by more expensive metal profiles. Metal crate, unlike wood, has the following advantages:
- Large carrying capacity with relatively light weight. This design feature ensures that flooring made from a lightweight metal profile does not increase the weight of the roofing pie and the load on the supporting walls or foundation.
- The possibility of overlapping roofs of large size. Due to the fact that the metal profile has a large length, as well as easily connected by welding, it is suitable for the installation of roofs of industrial buildings.
- High corrosion resistance. The steel from which the metal profiles are made for the assembly of the truss frame is not subject to corrosion when in contact with water, therefore, the sheathing of this material is much longer than wooden.
- Incombustible. The metal sheathing withstands high temperatures without deformation, does not burn, and also does not sustain combustion, therefore, it is considered a safer material for making sheathing compared to natural wood.
Important! Modern construction standards and norms recommend using a metal crate when overlapping structures with a high risk of fire (industrial buildings, baths, buildings with sophisticated technological equipment), as well as roofs with slopes longer than 6 meters.
Installation
Installation металлической обрешетки выполняется в процессе возведения кровли после окончания процесса сборки стропильного каркаса. If the crate is made of metal profiles, then the other elements of the truss system would be advisable to be made of the same material, comparable in weight and size of the section. Соединять между собой элементы можно с помощью крепёжных элементов из нержавеющей стали или посредством сварки. Installation обрешетки происходит следующим образом:
- First, install the trusses of the frame and strengthen them with braces or temporary expansions. It is important that the rafters form a flat plane on the upper ribs, on which it will be convenient to fix the roof covering.
- On top of the rafters spread waterproofing coating, which should protect the insulating material and the frame from the penetration of condensate and atmospheric moisture.
- If the lathing is of double type, then along the rafter legs, the slats of the contra-grille are fixed in order to create a ventilation gap between them and the roofing material.
- Then fixation of battens of the batten takes place with a pre-selected step. The elements can be fixed to each other with the help of welding or stainless steel self-tapping screws with a rubber seal.
Experienced craftsmen believe that a monolithic welded obreshetka of metal corners or profile has a maximum bearing capacity, and therefore withstands the intense snow and wind loads, which are famous for the Russian winter. To increase the resistance of the structure to corrosion, it is coated with paint.
