Do Weathervanes attract Lightning?

One of the frequently asked questions about weathervanes is whether they attract lightning, and if they are safe when mounted on the roof.

The basic thing to know about lightning is that it always looks for “ground”. A piece of metal sitting on your roof is not grounded, so it would not tend to attract lightning. You could compare this to the TV antennas that used to be on every rooftop a few years ago. These TV antennas were made of aluminum (which is a good conductor) and were typically not grounded or part of a lightning protection system. That said, lightning is an “act of God”, and one cannot accurately predict whether lightning can “hit” a particular area for a particular reason or not. Experts recommend that lightning protection for weathervanes should be an all or nothing proposition. You could either ignore it altogether – after all, the vast majority of weathervanes, metal roofs, church steeples, and even TV antennas are not lightning protected – or go for a complete lightning protection system that is professionally installed. If you choose to lightning protect your house, you are in effect attracting lightning and sending it to the ground. You must then do it properly.

Perhaps the most dangerous thing to do would be to go halfway, and just “ground” the weathervane using a small gauge wire. Trust me, this will be worse than doing nothing. Why? Because in this arrangement, you are attracting the lightning, and not providing enough means for the lightning charge to drain off safely. The result could be disastrous!

So, the crux of it is that if you install a weathervane on your rooftop, you may (1) install a full lightning protection system or (2) do nothing.

Thus, depending on your own choice, belief, and judgment, decide which route you would like to take, and enjoy the view of your favorite weathervane dancing, perched on top of your roof, year after year!