Is your motorhome protected against lightning strike?

What happens when a leisure vehicle is struck by lightning?

Carthago - European Innovation Award 2016

Many motorhomes and caravans already have built-in lightning protection given that vehicles that have an aluminium frame behave as a Faraday cage if lightning strikes, as indeed does a private car.

Carthago - European Innovation Award 2016

However manufacturers are increasingly using synthetic materials for the roof and walls because they withstand hail better and carrying out repairs is much easier. 

But what happens as regards the Faraday cage effect?

The motorhome that was given the European Innovation Award 2016 has a glass fibre reinforced plastic roof (GFK), but its walls have a sheet of aluminium and the manufacturer is also putting aluminium on the inside of the roof. This will ensure that any electric charge is conducted to the vehicle’s chassis.

Tests carried out by the University of Stuttgart have proved that this sandwich system does create a Faraday cage: the experimental lightning did not get through to the interior, so lives would not be put at risk. Nevertheless the high voltage did play havoc inside the vehicle. No control device could withstand such a high charge. 

A second experiment also showed that lightning that strikes directly above the skylight spreads out or scatters and seems to seek out the aluminium so, again, people would survive.

This would not happen in a motorhome or caravan made entirely from synthetic materials which is dangerous. All caravans have aluminium profiled sections now. A caravan or motorhome with a purely synthetic roof can be made lightning-proof if steps are taken to ensure that the roof is interlinked, i.e. making sure that the profiled section is linked to the chassis by means a some sort of metal strip or “railing“.

According to experts, the risk of anyone inside a leisure vehicle being struck by lightning is extremely  low. It is a bit more precarious though if the vehicle that you are driving is hit. But only because of the shock-element, the failure of assistance systems and on-board computers and the possible release of airbags.

A Faraday cage offers very good protection, so in an electrical storm it is advisable to stay in your vehicle and park it next to a flagpole, a high tree or a building. That is where the lightning will strike, not your vehicle.