What is a lightning conductor?
Lightning conductor (or a lightning rod, as they call it in the US) is a metal rod which starts from the roof of the building and leads to the ground. It’s designed to protect buildings from lightning strikes.
There are different types of lightning conductors; they can be hollow or solid; pointed or rounded. However, one thing is always true about lightning conductors – they’re all made from conductive materials, most commonly alloy, aluminium or copper.
How does a lightning conductor work?
There are many technical ways to describe how a lightning conductor works but the concept behind it is surprisingly simple. A lightning bolt is constantly looking for the path of least resistance to the ground. The lightning conductor provides just that – a straight, fast track for the electric current to use. It’s as straight-forward as this.
There is no guarantee that the lightning won’t “jump” and choose a different path on its way to earth. However, if your building is equipped with a lightning conductor taller than the building itself, this provides the lightning with what should be the perfect route to take.
It must be noted, however, that a single lightning conductor is usually only an element of a larger lightning protection system, which contains multiple lightning conductors.
What does a lightning conductor do?
In essence, the lightning conductor does exactly what it says on the box – it provides lightning protection. This means that a lightning conductor is of no use until there is a lightning strike right where your building is. Upon hearing this, you might think that the chances of this happening are too low and that the lightning conductor is all but unnecessary.
However, before you cross the lightning conductor out let’s have a look at what it does, or even what happens if you don’t have one installed. The lightning conductor has three main functions: to protect the structure of the building, the people in and around it, and the electrical equipment used. Here’s a little bit on what dangers it protects you against.
Property fire caused by lightning
What happens to a building if it’s hit by lightning? As you know the lightning conductor provides a straight path for the lightning to reach the ground. However, if you don’t have lightning protection, your building is in serious risk of fire caused by lightning. From starting a fire via a shortcut in the electrical circuit to burning through the very materials integral to the structure of the building (such as wood, gas and electric pipes), a lightning fire can cause serious damage. The worst part is that it usually goes unnoticed at the beginning, which means it’s definitely worth investigating in a good fire alarm.
Injury and death by lightning
The electric current carried by lightning is such high-voltage that it can be lethal, even if a person is exposed to it for milliseconds only. Sometimes, the electricity will, in a way, roll across a person’s skin without going through the body, causing only minor injuries (such as the infamous fern-like patterned burns on the skin). Of course, there also are cases where the unlucky victim of a lightning strike is lucky enough to go through the experience unscathed. That being said, on average, in the UK, 30 people are injured and two people die as a result of lightning strikes per year.
Damage to electrical equipment by lightning
If the electric current contained in lightning is strong enough to kill a person, it definitely can destroy any electric appliance. The sur-charge of electricity caused by a lightning strike will cause the wires to burn and can even cause power cuts.
Does my building need a lightning conductor?
If talking about all the dangers a bolt of lightning can cause hasn’t convinced you about the need to look into installing a lightning conductor, let’s talk about it a bit further.
If you’re wondering whether or not lightning protection for buildings is obligatory in the UK, the short answer is ‘No’. According to the lightning protections regulations (as satiated in the RC 35 ‘Protection of buildings against lightning strikes’), it is not a legal requirement. Having said that, you’re required by law to carry out a fire risk assessment every 6 to 12 months. If during a fire risk assessment your building is identified as being at high risk of being hit by lightning, then you would have to install a lightning protection system.
Some of the main factors which are taken into consideration when deciding the threat level are the building’s size and height, as well as the number of lightning strike incidents nearby. The bigger and taller the building is, and the higher the density of lightning strikes in the region, the higher the lightning danger level will be.