Do a google search
One example is http://www.lightningrod.com/manual4_why.html
I lived on the lower part of a hill that was regularly hit by lightning.
The main power line that supplied the community came over that hill and
every few years it got struck. If you have strikes so close it would be
prudent to put up lighting rods.
I have seen a hilltop above me being stuck by lightning while I was still
securing my sailboat. There must have been a four inch spark that jumped
between my fingers and the metal mast. The massive current that had to be
at least half a mile away had induced enough current to feel like a live
spark plug. Induced or stray currents can cause havoc with anything
electronic nearby.
At least put up a rod at the highest point on your property to draw a
strike.
Randy

"nospamgoingjag" wrote in message
...
Excuse the lengthy OT message, but I noticed that folks in this group
have built metal buildings for their workshops and though you might be
able to help me.

I am considering building a large garage/pole barn using metal.

I am very concerned with lightening strikes due to where I live.

My house is nearly the highest thing in town. When we get lightening
it's always dancing around us. There had been a tree next to the
house about 30 years ago, it would get hit by lightening and they
finally put a lightening rod in it. Eventually got taken out anyway
(big tree they cemented back together at one point). It was gone when
I got here, but I had to deal with the stump which is when I found the
braided wire from the lightening rod.

The roofs of the additions that were put on in the 20's were all metal
covered with tar. It's clear they were not maintained, as many
interior walls had damage, so they were probably exposed as I found
them for some time. The chimneys on either end of the house had
lightening rods, each fastened to their own ground, not in the middle
which I think would have been the right thing to do.
The ligtening rods were disconnected for at least the last 13 years
(since we've been here), but I just had to spend 3 grand having the
tops of both rebuilt as they were loose from being hit by lightening,
and bricks had started falling down.

We have an old three holer outhouse that is now a garden shed. It had
the same sheet metal roof in hip form, and I liked the look so left it
alone (unlike the house where I had the metal torn off and replaced
with a membrane roof). One day I was mowing the lawn and found a
piece of rusty metal, I looked over at the back of the outhouse and
there was a big burn mark and at least 3 feet of the roof had been
blown off.

When I was making some changes to a small old hay barn so my wife
could use the second floor, I noticed what looked like some singed
paper on the roof. Further inspection showed that it had also had a
metal roof, and had clearly been hit and burned by lightening.

If I look off into the woods on the hill to the left of our house, I
can see trees that used to be green that got whacked by lightening and
died from the hits (we think we know when it happened, helluva a
storm, but of course it took years for everything to go bare).

When we walk in the woods behind our house, every now and then we find
a tree top and occassionaly a whole tree that was clearly struck by
lightening.

I've searched around the net and can't seem to find any real input on
this. Someone told me that if I properly bond the building, I'll be
all set. Well this makes sense except it makes me wonder if a 30x60
chunk of metal is going to be so attractive that it will invite the
lightening and I'll end up with strikes on my wooden buildings?

Any real world experience would be greatly appreciated, since
everything I have found on lightening seems inconclusive.

Sorry for the lengthy post, and thanks for any feedback. If emailing,
remove nospam.