Protecting a wooden house from lightning. Do-it-yourself installation of lightning protection in a private house - requirements and recommendations

Technical measures defined as lightning protection of a country house in accordance with the requirements of the PUE should be considered taking into account the specifics of their implementation in each specific case. And, indeed, only rare private buildings are located near high-rise buildings with a lightning protection device placed on them. Many of these buildings are isolated and require special protection against lightning, which most often discharges into single objects.

Regulations

According to the current regulations (SNiP, in particular), all suburban residential buildings belong to the 3rd class of fire safety and are subject to mandatory equipment with lightning protection equipment.

At the same time, the arrangement of effective lightning protection for a cottage, for example, should be provided at the stage of preparing a construction project. This approach to solving the issue allows you to get a reliable fire prevention system, naturally integrated into the architecture of the house being built.

However, many owners of ready-made private buildings would like to protect their home on their own, which requires certain knowledge and skills. About how to competently and without unnecessary problems to mount effective lightning protection with your own hands and will be discussed further.

What to consider when installing

The type and effectiveness of lightning protection, selected individually for each rural building, depends on a number of factors. Here are the most important of them:

technical condition of a private house;
its location in relation to other objects;
the quality of the soil at the location of the protected private building, which ensures good grounding of the entire structure as a whole.

In the case of a building that is dilapidated and poorly protected from the effects of natural factors, the probability of its damage by a lightning discharge increases dramatically, which will require additional lightning protection devices from the owner.

Close location of high-rise objects

On the other hand, even brand new private homes can be affected by lightning if they are located in close proximity to antenna towers, large and tall trees or poles.

All of the listed high-rise objects are a good target for a lightning discharge and have the so-called "screen effect", which also includes a nearby residential building. When calculating the dimensions of the lightning rod mast, the presence of such objects nearby must be taken into account.

Soil condition

The quality of the soil at the location of the house is very important from the point of view of the effectiveness of the ground electrode used as part of lightning protection, the protective effect of which is based on the discharge current flowing into the soil.

In cases where the soil has low electrical conductivity in the country house or at the location of a country private house, it is necessary to worry in advance about artificial measures to increase it. This can be done by adding an aqueous solution of table salt or other chemicals to the soil.

It is also possible to compensate for the insufficient electrical conductivity of the soil by reducing the resistance of the down conductor and the ground electrode, to which the lightning rod is connected in a private house.

However, this option of increasing the efficiency of lightning protection, as a rule, leads to an increase in the cost of consumables and an increase in the cost of the entire system as a whole.

Particular attention should be paid to the choice of reliable lightning protection in a situation where there is a natural reservoir or a key source in the immediate vicinity of a private house. In areas with an indicator of thunderstorm activity of more than 40 hours per year, the risk of damage in this case will be maximum.

Lightning rod design

In order for a private country house on your own, you need to familiarize yourself with the principle of lightning protection.

At the moment of a lightning discharge, lightning enters a receiving device (a metal pin, cable or mesh), after which it is diverted along a special steel tape directly to the ground electrode.

In this part of the protective chain, current drains into the ground, accompanied by a sharp drop in the power of the electric charge.

Thus, self-arrangement of a lightning rod for a private house involves the manufacture of the following mandatory elements of protection against thunderstorms:

pin or mesh type lightning rod;
reliable down conductor (descent);
grounding device (lightning protection ground loop).

A typical pin lightning rod is made in the form of a thick steel bar with a cross section of about 10-20 millimeters and a length of about 2.5 meters. During installation, the pin is securely attached to any high point on the roof in such a way that its pointed end rises above this place by at least 2 meters.

Please note that either the ridge of the roof of a private house or a pipe that removes smoke can be chosen as the attachment point.

Let's make a reservation right away that the specified version of the lightning rod is ideal for. In the event that the roof of a private house is covered with slate, it is recommended to use a metal cable stretched along the ridge and securely fastened to insulating supports as a receiver.

For tiled roofs, the most optimal solution is to lay a special lightning protection mesh over their entire area with a system of wires extending from it.

Such down conductors (or descents) are made of a wire with a diameter of at least 0.6 centimeters or a strip of the same metal with a size of 2x30 millimeters.

During installation, they are laid along the walls of the building, and then welded on one side to the lightning rod, and on the other - to the ground loop, made according to the standard scheme (see PUE).

The procedure for arranging a lightning rod

It is best to start a lightning protection device for a suburban private building with the manufacture of a lightning rod. At the same time, the lightning protection pin itself is securely fixed at the highest point of the structure (on a pipe or on a wooden antenna mast). If a grid is used, it is laid over the entire area of the roof with the formation of cells no larger than 12x12 meters in size (this value is selected based on the dimensions of the roof and the required quality of lightning protection).

At the intersection of the wires, the grids are fastened for welding, and then fixed on the roof of the house with the help of special holders, well isolated from the coating material.

Several contact pads are arranged along the lower edge of the grid, designed to connect the down conductor system (a typical lightning protection project usually includes two descents for each wall of the house).

The part of the grid structure of lightning protection adjacent to the chimney can be made in the form of a loop of the appropriate size, which is thrown over it from above, and then attached to the base.

A lightning diversion device prepared in this way will provide high-quality lightning protection to any non-metallic roof of a private house.

We also note that for the manufacture of a lightning rod, a non-oxidizing material (galvanized steel or copper) should be used, since it is not allowed to be painted by the requirements of the standards. In the case when such lightning rods are made of a steel hollow pipe, one of its ends is tightly welded.

The procedure for manufacturing a ground electrode

The main purpose of grounding lightning protection is to provide ideal conditions for the spreading of the discharge current into the ground.

Fulfillment of this requirement is possible only with a minimum electrical resistance of the entire structure of the ground electrode, made from a set of metal blanks. As a rule, it is constructed from 3 thick steel bars or profiles at least 2.5 meters long, driven into the ground near the house (no closer than 5 meters).

These blanks are fixed in the ground in such a way that their tops form a regular triangle with sides about 1.2 meters long.

After that, they are connected to each other for welding using jumpers of the appropriate length, forming a solid and reliable grounding structure.

The structure obtained in this way can be used as a protective grounding of a private house. In the case when the grounding of the house is already available, it can be combined with a lightning protection grounding conductor into one system.

People living in private homes are afraid of lightning entering their homes. Some of them, in order to protect themselves from this, think about protecting the building. Their concern is understandable, since there are regions where lightning intensity can reach up to 80 hours a year. In such an area, it is necessary to install lightning rods. The device of such a structure, of course, requires certain costs. However, in some cases, they can be minimized if all the work on creating a lightning rod is done by hand.

Protection zone

It should be understood that any structures designed to protect against lightning have a limited range. They only protect the space around them. Therefore, when creating a lightning rod design, work must be carried out so that all objects located on the site fall into the protection zone. Only in this case they will be protected from lightning strikes.

At the moment, according to the degree of reliability, structures that protect against lightning are distinguished. There are two types of them:

type A;
type B.

Lightning rods of the first type provide 99% protection, which allows us to call them the most reliable designs against lightning. Structures of the second type provide 95% protection.

Device

If you are seriously afraid of lightning entering your house and, in order to protect yourself from this, you decide to arrange a lightning rod, then in this case, during work you will need to create the following items this building:

lightning rod;
down conductor;
ground electrode.

Lightning rod

This is a device that looks like a metal rod. After installation, it will rise above the roof of the building. It is on him that lightning strikes will fall. Thus, reliable protection of the building is ensured. In addition, such a device is able to withstand severe voltage loads that occur when lightning strikes. When creating this element, you can use various materials.

The best choice - flat or round steel, whose cross-sectional area is at least 60 square meters. m. This element has certain requirements in terms of length. This parameter must be at least 20 cm. The device must be placed strictly in a vertical position. The tallest building on the site is the perfect place to anchor it.

Down conductor

The down conductor has the form of a thick wire with a diameter of 6 millimeters. To create it, the best choice is galvanized steel. With regards to its location, it is better to choose areas where lightning strikes are most likely. For example, the edge of the gable can be a good place to place it. It can also be placed on a skate. The fastening of this element of the lightning rod is carried out close to the private house, but with a small indentation of 20 cm.

If the house is roofed with materials that are easily flammable, then in this case the gap is all the more necessary. To fix the down conductor you need to use a special fastener: nails and staples. For greater reliability of fastening of this element, clamps can be used.

grounding conductor

It is necessary to divert the current from lightning to the ground. When choosing a material to create this element of a lightning rod, it is necessary to use one that conducts an electric charge well. It is also necessary that the material has a minimum resistance. If we talk about its location, then this element of the lightning rod is placed near the porch of a private house, at least 5 m. It is not recommended to install a ground electrode in the immediate vicinity of the tracks, as well as in places where people can be. After placing it, to make sure it does no harm, you can create a fence around it.

When constructing a fence from the ground electrode, it is necessary to make an indent of 4 meters, and arrange the fence itself along the radius. If the weather is good outside, then it will not do any harm. But if it is cloudy, and even more so a thunderstorm has begun, then standing in close proximity to it can be dangerous to health. The ground electrode is installed in the ground. The decision regarding the depth of this element is made by the owner of the house. In doing so, the following points must be taken into account:

soil type;
availability of groundwater.

For example, if dry soil prevails on the site, and the groundwater level is low, a ground electrode system consisting of two rods is arranged. The length of each of them should not exceed 3 meters. The components of this element must be fixed to the jumper, whose cross-sectional area should be 100 square meters. m.

When this is done, the ground electrode is fixed to the down conductor by welding. After that, it plunges into the ground to a depth of 0.5 meters. In the event that the soil on the site is peat and has high humidity, and groundwater is located close to the surface, then there is no possibility of grounding half a meter. Therefore, in such a case metal corners must be used, which will act as a ground electrode. They are immersed to a depth of 80 cm.

If a multi-storey building is being built, then in this case, work on the installation of a lightning rod is carried out by specialists. These structures have their own radius of protection zone, which makes it possible to place them on each building. Before installing this structure, they check whether the already installed lightning rods are able to provide lightning protection for the erected building or whether it is necessary to erect a new one.

In the case of individual houses, the issue of a lightning rod is decided by the owner himself. There are a number of building placement factors that minimize the risk of lightning entering a home:

if a house is located in the lowest place on the site, the probability of being hit by lightning during a thunderstorm is small;
if a high-rise building is located next to the dwelling, then when a lightning strikes, it is more likely to be struck by lightning. Thus, your home will be safe;
if a lightning rod is installed on a neighboring house, then its protective zone of action may extend to your house. And in this case, there is no great need for a lightning rod device.

Thus, it cannot be said that a house that does not have a lightning rod is at high risk of being struck by lightning.

Options for creating a lightning rod

If you have inspected your own and neighboring houses and as a result found that there is no such protection as a lightning rod on nearby buildings, then in this case the most reasonable thing is to do the work on creating it yourself. Of particular danger are buildings whose roofs are covered with metal tiles or steel sheets. Although such a roof looks attractive, the lack of grounding increases the risk of lightning hitting such a house.

In most cases, the installation of this roofing is carried out on a crate, which is made of wood. This provides charge storage. The discharge of such a device can only occur after a thunderstorm. A person, touching it, can receive a current discharge of several thousand volts. In addition, do not forget that after a lightning strike, a spark can occur, from which a wooden house can easily ignite.

If you want to avoid such unpleasant situations, then need to think about grounding, which should be located every 20 cm. If your home has a metal roof, then in this case you can refuse to create a lightning rod. The roof material itself will become an excellent lightning rod.

To save your home from lightning strikes, you can install a lightning rod on its roof. However, other options are also possible. If there is a tall tree near your dwelling, then you can install a lightning rod on it with your own hands, but on condition that it is located at a distance of three meters from the building, and its height is 2.5 times greater than that of your house.

If this option of a lightning rod seemed attractive to you and you decided to arrange it, then you will need a 5 mm wire. First you need to prepare it, then one end must be buried in the ground, having previously welded it to the ground electrode. The other end will act as a lightning rod. It must be placed at the very top of the tree.

In the event that there is no tall tree in your area, you can use a lightning rod mast with two metal rods instead. Their installation is carried out at opposite ends of the roof. The drain in this case will act as a down conductor. Of great importance is the material of its manufacture. It must be metal. In this case, you should also not forget about the grounding device.

Conclusion

Regardless of which method you choose to install a lightning rod, you must remember that, having completed the installation of this structure with high quality, you will ensure a comfortable stay in your wooden house. But it is necessary to periodically check the condition of the lightning rod handmade. Particular attention must be paid to its connections. There should be no violations in them. Only in this case you can not be afraid of lightning strikes into the house.

How to protect your home from lightning strikes? Lightning is a natural discharge of electricity. If it were possible to accumulate a powerful lightning charge, this would provide an entire area of the city with absolutely free electricity. Sometimes, in our house, it can “fly in” through external wires, not tamed by anyone, and not so desirable, but so destructive for our home electrical engineering, a “blue dragon” named lightning and destroy all possible acquired property - electrical engineering. That is why, it is necessary to take the protection of the house from lightning seriously and responsibly and do not skimp on material costs for installing a lightning rod, as well as automatic protection.

There are two types of lightning protection: internal and external protection. Together, two lightning protection circuits will provide one hundred percent lightning protection for your home, which will protect both electrical equipment and human life.

Lightning protection - external protection

External protection includes a lightning rod, which, as a rule, is installed at the highest point of the house, the lightning rod is connected to a conductor that discharges the discharge to the ground. There was a time when a lightning rod was connected to the grounding of the house circuit. As it turned out, it is better to use independent grounding to divert a lightning discharge. The characteristics of the grounding conductor of the lightning rod must be the same as those of the ground loop of the house. It also needs to be deepened into the ground with the help of pins by at least 3 meters.

For private houses, the lightning rod is often installed on the roof of the house. Lightning rods are:

a) a wire lightning rod, fixed on the posts of the end parts of the house and stretched along the ridge, or a high metal rod of the lightning rod is used, which is vertically installed and fastened with braces or a special fastening designed to withstand wind loads.

protection of the house from lightning - lightning rods

b) another option, when a metal mesh of rods is laid on the roof, welded with a mesh spacing of 2–5 m, with a cross section of rods of 8–10 mm².

Lightning Protection - Mesh

c) the third version of the lightning rod is used if the roof is metal, then there is no need to use the two previous designs. It is only required to ground the roof with the help of a conductor and take it to the ground.

It is better to use a steel wire with a cross section of at least 16 mm², or a copper wire with a cross section of at least 10 mm², through which the lightning energy of lightning will go to the ground electrode system.

This is just the case when oil cannot spoil the porridge: the thicker the wire, the safer. The metal conductor is usually connected to the air terminal by welding or by bolting in the case of a copper conductor. The conductor descends along the outer wall of the house, to which it is attached using special clamps on non-combustible materials. It is advisable to lay the lightning rod conductor on a blank wall, away from the front door and windows. The conductor of the lightning rod should not pass through metal elements (stair metal railings, water and drain pipes) and at a distance of these structures no closer than 30 cm.

Lightning protection - internal protection

OPN - protection of the house from lightning

Internal lightning protection is provided by special modular devices that are installed in switchboard circuits. Even if lightning does not directly hit our house, it can “jump” in the form of a pulsed overcurrent along external street wires. A conductor that has taken an impulse can be disastrous for home appliances connected to the mains. You will have to pay for the fatal outcome of expensive equipment yourself, there will be no one to blame for this. Just to protect against such situations, there are special modular devices - surge arresters. Inside the shield (ASU), you can install surge arresters (OPN) that differ in classification. These devices are similar in appearance to conventional modular circuit breakers (VA), only without the trip lever.

Modular Voltage Surge Protectors - Lightning Protection

All you need to know about surge suppressors is that they are installed between phase and ground or neutral wire and ground.

The principle of operation of surge arresters

What surge arresters should be installed for lightning protection?

As can be seen from the class assignments of surge arresters, the repayment of impulse overvoltage occurs in stages. It is not enough to install a surge arrester only class D and calm down. The last stage is able to extinguish the residues that have slipped through B and C. So, alone, he is unable to divert hundreds, or even thousands of amperes. What conclusion suggests itself from all that has been said - it is necessary to install all three classes of surge arresters - B, C, and D.

Active lightning protection for a private house

Active lightning protection differs from passive - its predecessor, in that it has an integrated electronic device that generates high-voltage pulses at the end of the lightning rod. An artificial leader at a great distance, with the help of high-voltage impulses, will attract a lightning discharge to itself, and take it to the ground.

Active lightning protection is widely used in the field of civil engineering, in particular the construction of cottages. In our century, much attention is paid to the aesthetic appearance of the building, therefore, in order not to spoil the view with traditional lightning rods, some homeowners use active lightning rods. The advantage is explained simply: fewer lightning rods and down conductors - less violation of the aesthetics of the object

A private house and country cottages are often located in open space, where the buildings themselves are the only elevation. Because of what, during the thunderstorm period, there is a significant threat of lightning hitting buildings. Such a situation threatens not only electric shock to all people in it, but also the possibility of fire, which will lead to a fire and significant damage to property. Since no one can foresee the place where the discharge will strike, the most effective way to prevent its negative consequences is a lightning rod.

That is why it is important for most owners of private houses and summer cottages to install a lightning rod with their own hands. An exception may be buildings located in a lowland, the roof of which is below the top of the ground or falling into the protection zone of a neighboring building and its lightning rod.

The device and principle of operation of a typical lightning rod

Figure 1: lightning rod device

The whole design of the lightning rod is represented by three elements: a lightning rod, a down conductor and a ground electrode. Depending on local conditions and your preferences, each of them may have a different design. Now we will analyze why each of them is needed, and which option to choose in a given situation.