Lightning grid on a flat roof: in detail about the rules and principles of lightning protection

It is imperative to safeguard buildings from lightning strikes, as flat roofs are particularly susceptible. Lightning protection systems must be effective because it can cause extensive damage, including structural problems and fire hazards. Installing a lightning grid—which is intended to safely dissipate the electrical charge from lightning strikes—is one of the primary techniques employed.

A lightning grid is made up of conductive materials that are positioned thoughtfully throughout the surface of the roof. These materials are usually cables or strips made of copper or aluminum that are joined to create a grid pattern. The grid acts as a conduit for lightning, allowing it to pass harmlessly into the earth and away from any potential structural damage or occupant danger.

To guarantee a lightning grid’s efficacy, certain guidelines and precepts must be followed during installation. First and foremost, the grid needs to completely encircle the roof, leaving no spot exposed to lightning strikes. In order to prevent localized damage and distribute the electrical charge uniformly, this comprehensive coverage is essential.

An additional crucial component of lightning protection systems is proper grounding. The conductors of the grid are linked to deeply buried grounding rods or plates. This grounding lowers the possibility of electrical surges that could harm the building’s electrical systems by allowing the energy from the lightning to safely dissipate into the earth.

The design and installation of lightning protection systems, including those for flat roofs, are governed by rules and standards. Adherence to these guidelines guarantees the efficiency and security of the system. It is advised that the system be installed professionally by trained specialists to ensure compliance with these rules and to maximize system performance.

All things considered, installing a lightning grid on a flat roof is a dependable way to shield structures and people inside from the damaging effects of lightning strikes. Building owners can reduce risks and protect their investments from nature’s capricious forces by comprehending the fundamentals and adhering to installation regulations.

Prerequisites for the construction of lightning protection

We learn about the actual events where lightning causes home and residential buildings to collapse. It’s true that this does not give you license to let up on safeguards against unfavorable natural forces.

Even in situations where specific influences were initially absent, every blow poses a serious risk to the private estate’s owners and their animals.

When struck by lightning, they may experience:

• People and animals. The discharge that penetrates the construction in the wires of air communications can hit a living organism. It causes sparking at the points of connection and connection of devices feeding on electricity. If the house does not have a grounding system or grounded metal pipelines, currents can go through the body. The consequences are extremely dangerous.
• Residential and household buildings. Especially the buildings whose walls are made of fire – wood – wood. For concrete and brick houses, lightning currents are also very undesirable. From the point of the blow to the grounded object or land, high pressure occurs along with the temperature. This site is subject to internal destruction. There are cases when brick and wooden walls, which had previously survived several thunderstorms, split when lightning got.
• Private garages and small fuel warehouses. The category of lightning is accompanied by a sharp increase in the temperature of a kind of branched or linear channel through which currents occur. Channel contact with flammable products will uniquely entail fire and fire.

A 35 mm2 cross section metal guide is not threatened by lightning currents. Because the lower elements are grounded and the details are dependable connected by a metal connection, they do not pose a great threat to metal structures.

As an illustration, a metal crate is joined by welding to reinforced concrete walls, which are then connected to the foundation’s reinforcement. Roof elements collect the discharge, disperse it, and allow it to pass through the wall’s reinforcing bars. Next, currents travel through the foundation’s fittings before being relieved and sent to the ground.

Apart from fortifying the foundation, lightning strikes can also damage metal cables and pipelines buried in metal sleeves due to Earth-based lightning discharges.

We explore the fundamental guidelines and precepts of lightning protection systems made especially for flat roofs in this article. By examining how a lightning grid works and demystifying the technical aspects of its setup and upkeep, we hope to make sure that both professionals and homeowners recognize the significance of properly protecting structures from lightning strikes."

Lightning protection device

Found that a system needs to be built in order to shield buildings from lightning strikes. It is referred to as a "lightning rod" and consists of three parts that are equivalent in value:

• Lightning receiver – a device that perceives the category of lightning directly.
• Tokoowood – a system of metal linear parts taking currents from a lightning reception and transmitting them to ground. The already mentioned rods of reinforcement, metal pipes of drain, etc. can serve as elements.P.
• Group – linear or closed metal circuit. It consists of a vertical pin clogged into the soil connected by a rod or strip. The grounding ground is buried at least 0.5m. The length of the pin and the distance between them are determined by the calculated methods.

All three of the listed components must be included in the lightning line of any architectural construction; otherwise, the system’s meaning will be completely lost. Depending on how the building and roof are configured, there are variations in the kinds of components.

Rod receivers are installed on pitched roofs, for instance, to provide lightning protection. Over elongated houses, lightning rods equipped with cable receivers are installed. Although using these types somewhat degrades the architectural ensemble, it ultimately proves to be the most cost-effective option.

Features of lightning rods of flat roofs

Protection against flat-roofed residential buildings and lightning houses is implemented in accordance with a standard plan that has been tried and tested:

• The lightning receiver is performed in the form of a grid of horizontally laid round steel Ø 6-8mm. Instead of rolos, a steel strip with a section of 4 × 20mm can be used. As branches lightning
• The currently connected by the grounded metallic conductors made of round steel Ø at least 6 mm. The underground part is made from the rental Ø 10mm. Pipes and reinforcement can serve as elements of currents on flat roofs, if its use as a current -release was taken into account when designing the structure. Recommended distance between current -cutters 25m.
• The grounding system is a closed circuit covering the protected object around the perimeter. The distance between the ground circuit and the wall of the house with a flat roof is not more than 1m.

A metal roof lightning is a metal roof that is directly connected to current tributaries with a metal connection or to a metal crate. Only metal roofs joined by folds are appropriate for such circuits. There is no need for a protective grid in these situations, but that is a whole other "cover" story.

Metal tiles and profiled sheets with a protective coating are not included in the list of possibilities because they do not have enough connections to allow currents to flow through them and because a polymer membrane alters the material’s characteristics.

Details about the mesh receivers of discharges

Mesh lightning receivers can be installed during construction or after coating has been laid to mount the protective system.

If non-combustible insulation, waterproofing, and coating are applied, Option No. 1 may be feasible. Underneath the waterproof layer is the net. This kind of lightning rod’s implementation plan is created during the design phase.

Option No. 2 can be utilized without limitations. Its gadget essentially has no effect on how the house looks. The net is positioned over the coating and secured in holders that have been especially made for it. When building a soft roof with lightning protection, the holders allow a gap of 10–12 cm between the material that ignites and the lightning reception conductor.

Prior to installing the roof, the first plan establishes the protective grid device on the floor slabs. Connecting devices are installed, to which a grid is welded, and on the other hand, the reinforcement, in order to combine the branches of the grid with the reinforcement of walls or columns in the seams between the roof slabs. This kind of lightning system is constructed entirely of welding.

The receiver’s components are to be installed atop the roof in the second plan. In order to allow for the possibility of cleaning winter precipitation and unimpeded rainwater drainage, she also needs a simple project. The system’s metal components must be kept safe from corrosion.

It is advised to install lightning rods with mesh receivers on roofs that slope 4 degrees toward either the internal or external drainage. Rod brothers, which are installed at the intersection of conductors and in the corners of the construction, are frequently used in conjunction with mesh systems.

Rules for the construction of a lightning net

We acknowledge that most home masters will most likely run into issues if the first option is implemented. Ultimately, the imperfect connection between the reinforcement of the walls and the foundation and the grid depends on sturdy weld joints.

Their timeliness and quality must meet fairly strict guidelines. We will examine the regulations governing the construction of the second iteration of lightning protection on a flat roof, which we can manage ourselves.

General guidelines for lightning net installation:

• The branches of the lightning receiver are laid perpendicularly, forming cells with equal sides.
• In accordance with the Rules of the IEC (International Electrotechnical Commission), the step between the branches of the grid over residential buildings should not exceed 12m, above the garages with fuel storage up to 5m. Domestic requirements are slightly softer: 15m and 7m. However, it is advisable to adhere to international standards.
• All rising above the level of the device should be equipped with additional core receivers. These are pipes and masts of antennas, which should be attached to the common network.
• Welded joints are priority, but bolted analogues are also allowed. Especially if they use universal plasty clamps, significantly facilitating installation procedures.
• The branches of the mesh receiver are recommended to be attached to current wolf on each side.

More stringent IEC regulations require rod receivers to be installed in every cross connection of the grid. The rod needs to be 25 cm tall. For verification purposes, Tokoowalls recommends installing detachable plastic contacts on grounding rods and grounding them. Without a doubt, it’s time to adjust to international standards, but they frequently conflict with our ability to pay.

Such dragon claims are absent from domestic standards at RD34 number.21.122-87, and systems constructed in compliance with them have not yet failed. It’s possible that our moderate thunderstorm load is preventing our lightning rifle from functioning optimally. It is still preferable for citizens of the Fatherland’s southern regions to concentrate on international norms.

Remember that ignited and non-conjugate materials are present in a number of coatings for flat roofs. We categorize them based on a characteristic that can catch fire and examine the most popular designs.

Lightning grid on a fireproof base

Concrete screed, roof galvanized corrugated board, sandwich panels, and gravel backfill—which is utilized as a ballast in inversion roofing systems—all fall under the category of non-combustible bases.

The lightning net installation plan is chosen based on the kind of non-combustible base:

• On profiled sheets, not having a polymer coating, laying is carried out across the direction of the corrugation. A metal bar is laid with a planned step and is welded to the surface of the wave of corrugated board through each meter. An excellent alternative welding are metal bolted holders that allow the installation of a mesh receiver of any degree of complexity.
• By concrete roofs According to design data, plastic holders with concrete filling are installed – weighting. The mass of filling from 12 to 17 kg depending on the brand of products. The impressive weight of the products guarantees the stability of the system and resistance to impulsive winds. There are holders on sale without weighting filling, for the installation of which a load of frost -resistant concrete is poured independently at the facility. For low -rise buildings in regions with low wind activity, holders with fastening self -tapping screws or gluing on bitumen mastic are produced.
• By gravel backup ballast roofs are installed by holders with concrete ballast and without it. If desired, the holders on the basis of them are mounted before filling the ballast. In such cases, it is recommended to use distance models with gluing to the base on mastic.

For each of these schemes, the maximum step for installing holders shouldn’t be more than one meter.

It is not advisable to install lightning rods with mesh conductors on metal roofs composed of less than 4 mm of material. It is easy to burn the coating with a straight blow.

As a result, it’s common practice to equip thin profiled sheet roofs with a net on remote holders, whose protection zone is still larger than the contacts that are in direct contact with the roof.

Mesh receiver on a combustible base

Since roofing coatings are not used in construction, we will classify them as weak-willed materials and materials that facilitate combustion. The list of coatings for flat roofs that are dangerous based on the criteria for coating combustion includes polymer membranes, bitumen, and bitumen-polymer waterproofing materials, also known as soft roofs.

The so-called remote holders are used to prevent the lightning discharge receiver from coming into direct contact with bitumen and polymer coating. The fundamental idea behind the design of simple devices is to create enough of an air gap to allow a potential spark to attach between the mesh branch and the roof surface.

The distance must be at least 10 cm in accordance with 153 3.2.2.4’s requirements. IEC regulations state that the insulating coefficients of the materials denoted by the letters KM must be used in the computations.

The vertical rods that come with the set of distance holders are used to create insulation intervals. The concrete weighting is raised onto a plastic stand that has them fixed in place. The sleeve, the last fastener, completes the task of fastening the wire.

The following is the algorithm for the lightning mesh device on a soft roof with remote holders:

• We mark the work site according to the developed project. Holders are installed after 1m along the lines corresponding to the mesh cells. The maximum distance between devices is 1.2m, the possibility of increasing is stipulated in the instructions by the manufacturer. The design development should take into account that the sections of the connection of branches to current cargoes and tokoosovs to ground should be minimal. Do not forget that the function of the branch can perform a metal panel of the parapet and similar long metal parts.
• We cut the rods made of fiberglass or chop off on a pre -calculated value required to form an air insulating clearance.
• According to the marking, we install plastic stands, the center of which is obliged to coincide with the marked point. In the case of arranging a roof from a polymer membrane under each stand, lay a rubber gasket so that heavy parts do not damage the coating.
• We put concrete weighting stages on the stands.
• In the channels located in the center of the stands, we freely place the cut rods.
• The tops of the rods are equipped with fasteners with bushings designed to fix the wire Ø up to 8mm.
• We lay the branches of the lightning net, elementaryly snapping them in the bushings of holders.

The lightning rod should be electrically connected to the pipe and antenna masts that extend above the surface. They have plastic clamps to secure them to current carriers and are fitted with rod receivers or metal aprons. Similarly, rather than welding, current wraps are used to secure the branch edges. This method is far more practical. Furthermore, an inexperienced performer can quickly and efficiently produce high-quality nodes with their assistance.

Connection of current -deeds with mesh branches

The first step toward a complete grounding system and lightning protection device is merely the assembly of a mesh receiver of categories. For the approved currents to flow into the ground without any obstructions, it must be correctly connected to the grounding contour.

Guidelines for connecting and laying current carriers:

• The routes of the passage of Tokoowalls must be designed taking into account the shortest distance between the points of connection to the lightning receiver and grounding.
• Tokoodes are attached to the ignited walls with the help of distance brackets. The distance between the wall and the conductor is at least 10cm. Contact of the metal bracket and wall material is allowed.
• Tokoowalls can be fixed on drain pipes with metal clamps.
• It is allowed to lay current -deeds made of galvanized round steel, directly along a brick or concrete wall.
• The distance between the mounting points of horizontal sections 1m, vertical sections 2m.
• The laying of the loops is not allowed.
• When choosing a place for laying current wore, it is recommended to choose plots of the building with the lowest probability of the presence of people.

The equipped houses’ corners are used for okoowood routes. There is a maximum of 25 meters separating them. Each current release’s lower edge is lowered into the earth, where a bolt device connects it to the grounding system. It is advised to use anti-corrosion tape to wrap the splash in the soil input.

To protect a flat roof and its occupants from the destructive power of lightning strikes, a lightning protection system must be installed. Because of its large surface area and frequently elevated position, a flat roof is especially susceptible to lightning strikes. The danger of fire, structural damage, and even personal injury increases dramatically in the absence of adequate protection.

A few fundamental guidelines need to be followed when putting a lightning protection system into place. Typically, the system consists of conductive materials that are placed strategically all over the surface of the roof. These substances function to deflect lightning strikes and safely carry electrical current to the earth, where it will naturally disperse. In order to guarantee efficient electrical charge dissipation and avoid hazardous build-ups that might otherwise be dangerous, proper grounding is crucial.

Lightning protection system installation and maintenance are governed by regulatory standards and guidelines. Adherence to these guidelines guarantees not only legal compliance but also the efficacy of the system. It takes routine testing and inspections to make sure the system is still completely functional and able to shield the building from lightning strikes.

A lightning protection system’s design should also take the flat roof’s unique features into account. Where and how the conductors are installed depends on various factors, including the size, shape, and material composition of the roof. Engineers can maximize the system’s dependability and performance by designing it to take these factors into account.

In summary, even though installing a lightning protection system on a flat roof necessitates following particular guidelines, its significance cannot be emphasized. Property owners can reduce the risks associated with lightning strikes and preserve the safety and longevity of their buildings by investing in a well-designed and installed system.

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