Hero

Lightning protection
systems

Designed, installed and tested to BS EN 62305.

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The whole system

A lightning protection system is not a rod on a roof. Under BS EN 62305-3 it is a set of parts that have to work together: an air termination network to intercept the strike, down conductors to carry it down the building, an earth termination system to disperse it into the ground, and equipotential bonding so nothing inside the building sits at a different potential while it happens.

Get one part wrong and the rest stops being protection. A down conductor routed too close to a metallic service without the required separation distance will flash over to it. An earth termination system in poor ground will not disperse the current fast enough. This is why the standard treats design, installation and testing as one process rather than three purchases.

We do all of it, and we certify what we install.

Included

  • Air termination network, whether that is a mesh, rods, or conductors following the roof geometry.
  • Down conductors sited to suit the elevation and the required separation distance.
  • Earth termination system sized against measured soil resistivity.
  • Equipotential bonding to structural metalwork and incoming services.
  • Test clamps and joints at accessible points so the system can actually be tested later.
  • Surge protective devices where the risk assessment calls for them.

New buildings

On a new build the cheapest and least visible lightning protection is the one designed in early. We work with architects and engineers at the point where the frame is still on paper, because a reinforced concrete or steel frame can often be used as the down conductor system itself.

That means connections at the pile caps, continuity through the frame using continuous strip or starter bars, and a route to earth established before the slab goes down. Retrofitting the same protection to a finished building costs more and shows.

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Existing buildings

Older systems were designed to BS 6651, which was withdrawn in 2008 and replaced by BS EN 62305. A system installed to the old standard is not automatically unsafe, but it was designed against different assumptions, and the current standard asks different questions about surge and about risk to life.

We apply a BS EN 62305-2 risk assessment to what is already there, tell you whether it still does the job, and where it does not we set out the work in order of risk so you can spread it across budgets rather than doing everything at once.

BS EN 62305 explained

Common questions

What is a lightning protection system?

A lightning protection system gives a lightning strike a controlled path to earth so the current does not travel through the structure, its services or the people in it. BS EN 62305-3 splits it into an air termination network on the roof, down conductors on the elevations, and an earth termination system in the ground, all bonded together.

Can an electrician install lightning protection?

Not usually. Lightning protection is a specialist discipline with its own standard, BS EN IEC 62305, its own competence route and its own trade body in ATLAS. An electrician can install surge protective devices inside the building under BS 7671, but the external system, the earth termination design and the certification need a lightning protection specialist.

How much does a lightning protection system cost?

It depends on the height of the building, how the roof is constructed, how the down conductors can be routed, what the ground is like and how you get access. A small church tower and a distribution warehouse are different jobs. We quote from drawings or a site visit rather than giving a figure that will change.

Do you work outside the South East?

Yes. We are based near Crowborough in East Sussex with a second office in London, and we work across the UK. Our client list includes national infrastructure operators, so travelling to site is normal for us.

Transport for London
  • What we did for

    Transport for London

    Transport for London is one of the infrastructure operators on our client list. Work on the transport network is less about the lightning protection itself than about everything around it: access, permits, isolation and a programme that cannot overrun.

Need a quote?

Send us the address, a roof plan if you have one, and what you already know about the building. We will tell you what is needed and what it costs. Call 01892 667258 or use the form.

Talk to Braileys
01892 667258