Perhaps a thunderstorm in any person causes excitement. And this is right, since lightning is fraught with great danger, it can affect not only tall trees, but also buildings, as well as people. It is because of the lightning strike that a large number of fires occur even today, and because of discharges in the building, electrical networks can be closed. Surprisingly, today many means against lightning have been invented.
Even our distant ancestors learned to defend themselves from lightning strikes using lightning rods. Modern architecture does not neglect this element of protection. It is required for all varieties of roofs, but some believe that metal roofs do not need this. Before installing such a device, you need to understand the principle of lightning protection, and also decide whether you need this design.
The need to protect the roof from lightning
Installation of lightning protection, as a rule, is carried out on roofing material or a wooden crate, but this approach cannot be called safe. It also happened that lightning fell on individual elements of the roof, causing melting and fire, which led to ignition of the lining material. Among other things, if lightning hits metal floors and heats them to high temperatures, then the wooden rafters may catch fire.
Installation of lightning protection is also necessary for a metal roof, since it can only be protected from fire by non-combustible materials, this also applies when all metal elements are connected to each other as reliably as possible, and there is no electrical connection between them. An excellent addition to this will be the grounding of the steel coating.
Lightning protection device
Lightning protection will protect the building from fire and preserve electrical equipment. Such protection can be divided into external and internal, the first eliminates direct lightning strikes, and the internal guarantees the safety of the electrical network during surges of electric current.
If we are talking about an internal system, then bit devices are used that limit the voltage. The simplest and most affordable means of internal protection is the shutdown of all electrical appliances. This is especially the case when lightning entails thunder in less than 8 seconds.
Installation of lightning protection for external purposes involves the installation of grounding, down conductor and air terminal . The function of such a system is very simple: the air terminal will take on the effect at the roof itself, and after that it will go into the down conductor, while the grounding will neutralize the energy in the soil.
It is noteworthy that such a system can be manufactured by you independently and in the shortest possible time. To do this, use an earthing switch, down conductor and an air terminal. You will need metal staples, a welding machine and clamps, the last of which will connect down conductors.
Installation of an air terminal on a steel roof
If you decide that the installation of lightning protection will be carried out on a metal roof, then install it at the highest possible place. If the building has a rather complicated structure, it is recommended to use the installation method of several lightning rods. By design features, they can be in the form of a grid; a cable installed along the ridge; as well as a metal pin.
Obneny work
Installation of lightning protection of buildings with a metal roof is usually carried out by installing a pin, the length of which can vary from 0.2 to 1.5 m. It should be located vertically and at the highest point of the house. The pin can be made of metal, which is not subjected to oxidation under the influence of negative environmental factors. It can be copper, aluminum, galvanized steel or duralumin. The upper part should have a cross-sectional area that is greater than 100 mm 2 , while the diameter should be 12 mm.
If you decide to use a hollow tube, then its upper end is welded. You can completely independently carry out installation, the roof, the lightning protection of which was carried out without outside help, will effectively remove the danger from the house. However, it is important to remember that it is impossible to isolate and color the lightning rod. If the roof is equipped with a television mast, which can be metal, then the air terminal can be made from it. For this, it is permissible to use a metal weather vane. The main condition for this is grounding. In some cases, the air terminal is located on the chimney, but this cannot be called correct, since a fixed metal pin is able to create wind loads that damage the pipe.
For reference
As an alternative to a lightning rod, you can use a tall tree, whose branches grow above the roof. It should be located next to the house. In this case, the air terminal should be fixed on the top of the tree so that the element rises above the crown by half a meter or more. As practice shows, a lightning rod is able to protect from lightning an area that falls into an imaginary cone. Its vertices are located at the end of the air terminal, and the side parts are at an angle of 45 °.
This circle is a safe area, which allows us to conclude: the higher the lightning protection device is, the wider the safe area. In other words, the height of the lightning receiver should be equal to two dimensions of the safe zone. It is important to remember that under this protective cone should fall not only a residential building, but also all outbuildings.
Different types of lightning rods
Installation of lightning protection on a soft roof can be carried out by various technologies. The first involves the installation of a metal pin, the second - a metal cable, while the third - lightning protection mesh. In the first case, the element can be installed even on the ridge of the roof or mast of the antenna. A metal cable is stretched between two supports, the height of which can vary from 1 to 2 m. These components must be positioned along the roof ridge.
In order to ensure the reliability of the structure, metal supports can be used , however, they are isolated from the cable. This method is effective on slate and wooden roofs. You can independently perform the installation of grounding, lightning protection, for example, it can also be represented by a grid. It is fixed along the ridge of the roof, and grounded down conductors should extend from it across the entire surface of the roof, this option is ideal for roofing. It is important to remember that lightning rods must be paired with existing metal objects on the roof, including stairs, gutters, and fans.
System mounting methods
The installation of lightning protection on the roof with a soft roof can be installed in one of two ways: the first involves the use of a tension system, and the second - remote clamps. The tensioning system is carried out using rigid anchors at the base, a cable is stretched between them. Such a system is equipped with tension clamps, and the distance between the anchors should be from 20 to 30 m. If we are talking about a flat roof, the air terminal can be supplemented with distance elements, for example, plastic brackets. If you have to work with flat roofs and walls, then you can use self-locking and corner clamps, which are strengthened with dowels. On steep roofs that are covered with ceramic tiles, it will be more difficult to fix the clamps. In this case, a ridge variety of them is used, which is suitable in size and shape to such a covering material.
Cost
You can not independently install lightning protection, the price of such work with specialists reaches 6,000 rubles. But in this case there is a guarantee of quality.