What makes lightning set a house on fire? Anything you can do to prevent it other than a lightning rod?

Question

Does lightning usually cause house fires by superheating the wood of the house, or by superheating the electrical wiring? Anything you can do to prevent/minimize damage other than putting in a lightning rod? Thanks!

Answer 1

Fire department investigators have reported several different ways that a house fire can be caused by lightning. Much depends upon the type of structure and locality.

The most common is a fire in the attic or roof caused by the lightning drying the wood and then igniting it. The ignition is usually near the point of contact of the lightning bolt.

Seldom is the electrical wiring of the house involved. The Gauge of the copper wire is so small compared to the amount of electricity to be carried that it tends to melt or even evaporate if the lightning attempts to use it as the primary conductor.

Lightning typically will strike the highest elevation at the location of charge build up. In some cases a tree close to the house will be hit and then burst into flame. The burning tree then ignites the house roof or upper wall to start the house fire.

A properly installed lightning rod grounding system is the only effective method of prevention. You may want to check with your local fire department.