Metal Myth #: Metal Roofs Attract Lightning
When you start talking to your friends and family about your new metal roof, inevitably someone will gasp and say, Dont you know that your metal roof attracts lightning! They might try to convince you to avoid metal roofs in order to avoid attracting lightning strikes.
Did the clock tower in Back to the Future have a metal roof? Probably not! Source giphy.com
Heres How A Lightning Rod Is Installed On A Metal Roof
To ensure the highest standard in safety, the rod is designed to draw all the negative charge of electricity from the building. The rod ingenuously draws all electricity to itself and transfers it to a system of cables, made up of copper or aluminum wire, so that the building is protected from the intense surge of electricity.
Do You Need A Lightning Rod On A Metal Roof
Lightning is among the leading cause of deaths related to weather. Additionally, it causes an average of 22,600 fires per year in the US alone.
Apart from deaths from the resulting fire, it also damages property with an estimated worth of 451 million per year. Therefore, it is important to take preventive measures.
There are a lot of myths about installing a lightning rod on a metal roof. Some people believe that they are safe without it, while others are unsure. In this article, I will debunk all the myths and explain everything you need to know.
Contents
Do you need a lightning rod on a metal roof?
Yes, you need to install a lightning rod on a metal roof. Although metal roofs do not attract lightning, they dont prevent it from striking the building.
There is a misconception that associates lightning strikes with roofing materials. The fact is all of them have equal chances. You still need a lightning protection system to mitigate the dangers of a strike.
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Lightning And Metal Roofs
Lets get something out of the way right off the bat: The chances that your home will be struck by a bolt of lightning is small but not that small. Some sources report the likelihood at around 1 in 200.
Second, metal roofs do not attract lightning. The only real protection from lightning comes via the installation of a lightning protection system with rooftop air terminals aka lightning rods.
Lightning takes the path of least resistance to the ground. Building materials a metal building or a metal roof play a role in determining how much damage is likely to occur if lightning uses a certain building as an electrical conductor.
But as far as the likelihood of lightning strikes goes, The Spruce sums up the relative danger this way.
When lightning strikes, they write, it is seeking a path to ground and almost always will strike whatever object is highest in the area that also has a direct path to ground. Your metal roof is not grounded, and thus lighting has no reason to strike it.
Not that lightning has any reason at all. Were talking about electrical conductivity here. And chances are there are high points and higher objects in the vicinity of your home that will attract a lightning strike much more readily than your aluminum roofing system.
Thats if you live in an area of the world that has a lot of lightning storms. Here in the Pacific Northwest and the West Coast in general lightning is much less frequent than it is in the South, for example.
Installing A Lightning Protection System
- Opposite charges of electricity attract one another every structure on the ground has a negative charge of electricity on it.
- When a lightning storm hovers over those structures, the clouds are charged with positive charges which attract anything nearby with negative charges
- By installing a lightning rod over a structure, such as a house, for instance, the negative charge can be drawn, which is safely diverted into the ground through a series of cables.
- The cable should be a 17-gauge red copper wire, which goes 10 feet into the earth for proper grounding. An electric ground rod hammer can be used to drive the copper wire into the ground.
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Does A Metal Roof Lower Your Insurance
Thats why having a newly installed roof can save you on insurance premiums. Insurance companies also look favorably on metal roofing because research has shown that homes with metal roofs receive less damage from storms and house fires, which means the company is much less likely to have to pay an insurance claim.
Should I Install Lightning Rods On My Metal Roof
In most situations, it is not necessary to install lightning rods on your metal roof. Lightning strikes to homes are rare. If your roof is the highest point of a surrounding area, you may consider having a lightning safety system installed on your home.
You can install lighting rods yourself, however we recommend you hire a professional. There are several things to consider when installing lightning rods on your home. In the event of a strike, a lightning safety system is designed to filter the flow of electrical current safely away from the home. So, ensuring it is installed correctly is key. Perhaps most important is having your lightning protection system grounded properly.
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Lightning Strikes Metal Roofs
Lightning strikes metal roofs more often than any other type of roofing material. This is because metal conducts electricity and is therefore more likely to be struck by lightning. Metal roofs are also more likely to cause fires when they are struck by lightning.
Many people believe that metal roofing is a lightning attractor. Its not concerned with your metal roof because lightning only wants to make contact with positively charged electrons as quickly as possible. Topography is a better indicator of lightning strike risk than building materials. The structural strength of a metal roof protects your home from both lightning strikes and electrical currents due to its non-combustible nature. If you want to improve the appearance of your roof, consider metal as one of the best materials to use. You can learn more about the types of metal roofing materials available by visiting our blog on 5 different materials.
What Happens When Lightning Strikes A Building
Lightning is nothing to take lightly. It is a serious threat to people and property and should be taken seriously. A few things can reduce the potential of lightning damage including:
- Construction materials – if the framing and roofing of a structure are electrically conductive the charge from a lightning strike will pass through these materials and not build up heat through resistance reducing the possibility of fire.
- Building materials – if the building is constructed with non-combustible materials they will not be a fuel source for a possible fire resulting from a lightning strike.
- What’s in the building – sensitive flammable materials in the building are susceptible to ignition.
In fact, a properly grounded metal roof, in accordance with the requirements of NFPA 780, will actually conduct the energy from a lightning strike over the broader area of the roof reducing the amount of heat transferred to the building and reducing the potential of damage due to fire. As an electrical conductor and a noncombustible material, the risks associated with use of a metal roof may even be a more desirable construction option.”
Please read the MCA Lightning Best Practices Guide and the MCA technical bulletin Lightning Strikes and Metal Roofing to get the latest up to date technical information so that your next roofing project is as lightning safe as possible.
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Do Metal Roofs Need To Be Grounded
A metal roof, in a nutshell, does not require to be grounded. It is usually not a risk to ground it without incurring additional liability. Electricity can be produced from the metal. When it comes to a full roof, lightning strikes would not harm the structure as much as non-metal roofs would.
The National Fire Protection Associations building codes do not specify whether a metal roof should be ground up. If you dont ground the metal roof, you wont be exposed to additional safety risks. Metals are inflammable in nature, making them less likely to catch fire if lightning strikes on rare occasions. The truth is that there are no lightning bolts on metal roofs. A metal roof has the same path as a standard roof on the same structure. PVC piping is only permitted to be installed up through the roof of a house, as it is only permitted within the interior. Using a metal pipe in a home will result in a lack of grounding and will allow the pipe to travel down the inside of the home undetected.
The External Lightning Protection System And Its Purpose
The external lightning protection system consists of an arrester, a conductor and an earthing device.
The rolling sphere method is the most common method used to determine the preferred impact points during lightning protection planning. Arresters are installed at these locations to protect that part of the building these catch the lightning and ultimately discharge it to the earth via a conductor. If metal components or claddings are present on a building , these can function as a natural part of the external lightning protection system subject to normative provisions. This can in turn yield substantial savings potential when installing the lightning protection system.
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Fire Ratings For Roofing Materials
Founded in 1903, Underwriters Laboratories is a not-for-profit organization that independently tests and certifies products, including roofing materials. Considered the national standard for a roofs ability to withstand fire, the UL 790 test rates roofing material performance when exposed to fire sources originating from outside the building.
To meet UL standards, roofing materials must provide a degree of protection against flame penetration to the underlying deck and the attic space without producing flying embers, or slipping from their installed position. Based on their performance in the UL790 test, roofing products are classified as either Class A, Class B or Class Cwith a Class A rating being the highest.
Class A materials have proven themselves effective against the most severe fire testing. They provide the best protection against flame penetration as stand-alone roofing products with excellent resistance to surface flame spread without the need for chemical treatments or extra underlying roofing materials.
Class B materials are effective against moderate fire exposure. Some roofing materials, such as wood shingles or shake, must utilize fire-retardant chemicals to achieve a Class B rating.
Unrated materials are unable to meet any of the above classifications.
Metal Roofs And Lightning
Having a metal roof does not increase the likelihood of your home being struck by lightning. Generally, lightning discharges depend on the geography, topography and movement of the storm. And, when lightning is ready to discharge, it will do so regardless of whether there is a metal roof nearby or not.
Another misconception that needs to be cleared is that lightning rods and metal roofs work in a similar way they attract lightning. But the fact is that lightning rods are actually designed to protect a structure during lightning strikes. These rods ensure that lightning is channeled safely to the ground so that it wont cause damage to your roof or home.
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Lightning Protection Systems: Why You Need One
Conductive materials such as metal roofing should be used for lightning protection. Despite the urban myth that conductivity metals attract lightning, they actually give electricity a path to follow rather than attract lightning. There are three main types of lightning protection systems: wiring, rods, and cable. The average cost of wiring one is $432, while the cost of rod systems can range from $3,000 to With over 50,000 installations, thousands of buildings, plants, and factories, the best Lightning Eliminators and Consultants system is regarded as the industry standard and is installed on thousands of towers, buildings, plants, and factories. LEC lightning protection continues to be effective due to the superior quality of their design.
The Basics In Lightning Protection Systems
- Lightning is a flow of electrical current between the earth and the sky. The result of this dangerous electrical flow results in billions of dollars of lightning-related damage, annually.
- It is a false belief that metal roofs can increase the risk of a lightning strike. Metal roofs are no more attractive to lightning than any other type of roofing material.
- While a buildings structural steel will conduct lightning, it is the bonding, interconnection and grounding provided by a lightning protection system that will dissipate lightnings harmful electricity safely to the ground.
- When lightning strikes, an LPS offers assurance. An effective LPS not only protects roofs, walls and other structural components from direct lightning strikes, but it also shields electrical circuits, communications, process control systems and other elements that are vulnerable to indirect strikes.
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Pros And Cons Of Lightning Rods
If you live in Florida, Georgia, or Texas, its reasonable to install lightning rods for homes. With Georgia topping the charts accounting for over 3800 insurance claims, residents have a hard time coping with millions of dollars lost every year. Lightning rods are a possible solution to this problem. But before going through the Pros and Cons of Lightning Rods, its imperative to understand them.
Lightning rods are devices made of metal mounted on the rooftop of a building to protect it from lightning strikes. Lightning is an electrical discharge that forms in the atmosphere when there is an imbalance in thunderstorm electric currents.
These imbalances cause positive and negative charges to build up in the storm clouds, with either side reaching a certain threshold enough to send sparks into the lower atmosphere. Today, most people rely on lightning rods simply long metal poles mounted on buildings or other structures during high risk for thunderstorms.
The origin of installing lightning rods was credited to Benjamin Franklin, who proposed them in 1752 during his lectures on electricity. His ideas were not accepted, but many roofs were equipped with lightning rods after his death.Moreover, the losses due to thunderstorms cost in terms of money and lives.
Lightning Rod Installation On Metal Roof
When installing a lightning rod on a metal roof, be sure to use a non-conductive material such as plastic or rubber to avoid damaging the roof. It is also important to install the rod in a location that is not exposed to direct sunlight, as this can cause the rod to overheat and potentially catch fire.
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How A Lightning Rod Works
Also known as finials, lightning rods were invented and developed by Benjamin Franklin in the 18th century. They began as a simple device attached to the highest point of a building, house or piece of terrain. Although many people believe that lightning rods attract lightning, they actually provide an alternative pathway for lightning. The pointed metal rod on top of a building is connected to a copper or aluminum wire, which is in turn attached to a conductive grid buried in the ground. This system diverts the harmful current away from the building, helping prevent fires and other electrical damage.
Why A Lightning Rod Is A Worthwhile Home Improvement
Some homeowners wrongly think that a lightning rod installation is only a necessary home improvement if the house has a metal roof. However, metal does not attract lightning any more than other kinds of roofing material. Furthermore, materials used in metal roofing are non-combustible, making fire less likely to occur if ever lightning strikes. Regardless of the materials used for a roof, a finial is a worthy investment, especially if you live in an area prone to lightning strikes. Compared to the cost of other common home improvements, installing a lightning rod is inexpensive. For a nominal fee, youâll get a device that prevents fires that can destroy your home and jeopardize your familyâs safety. As a plus, some homeownerâs insurance plans offer incentives for lightning protection. Contact your insurer to see if your current plan offers this feature.
Keep your home safe from lightning strikes with help from the professionals at Bel-Aire Home Improvement. Theyâll do a thorough assessment of your home before outfitting it with a reliable lightning protection system. Located in Platteville, WI, they offer home improvement services throughout the entire tri-state area. These services include roof and window installation, as well as speedy storm damage repair. Schedule a consultation by calling 348-Â2381 or sending a message via their website.
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What Happens When Lightning Hits A Metal Roof
When lightning hits a metal roof, it will likely hit the ground outside the home. This is because the lighting is conductive and provides a path for the strike to go outside the home and into the ground.
In most cases, the strike will be redirected and will not go into your home or cause damage to the home.
