Lightning Protection System

by | Apr 28, 2001

Here’s a view of the lightning rod with a red glass ball for decoration.

Spare the Rod and Spoil the House
Last summer I had quite a scare when the house took either a direct or indirect lightning hit. Although no damaged occurred, my heart pounded for at least 10 minutes afterwards. So as quick as a flash, the thought of a lightning protection system seemed prudent.

Thanks to Ben Franklin (not to steal his thunder), lightning protections systems have been in use for over two hundred years. No house should be without a lightning protection system. (Shockingly, I am amazed though at how few of them are installed here in the Midwest.) For a couple hundred dollars it’s a cheap investment to protect your house from a lightning strike. Lightning strikes can do all sorts of nasty things to your house and electrical appliances. Lightning causes millions of dollars of damage each year, many times resulting in total property loss. Lightning has the power to rip through roofs, explode walls of brick and concrete and ignite deadly fires. It surges throughout power lines causing wire damage and destruction of valuable electronic equipment including computers, televisions, stereos, security systems, etc. So for a couple hundred dollars, I think it’s a wise investment.
The system that I installed this week was designed specifically for our house by a company that specializes in lightning protection systems. (There are plenty of reputable lightning protection companies that can design a system to protect your house — no matter what shape or size.) Because our house is nearly round, the house only required one lightning rod and two ground rods.

Two eight foot ground rods were pounded into the ground at opposite sides of the house. This provides enough surface area to adequately discharge a lightning strike to the rod.

I started by installing the lightning rod at the top of the cupola. (The original intentions were to mount the lightning rod from the inside of the cupola, but the metal roofing cap on the cupola made it too difficult.) This made things a little trickier, but I was able to mount the rod from the outside. (It did require strapping a 4′ step ladder to the cupola, so I could get up to the top. Luckily, I did not lose my ladder this time!)

The lightning rod is constructed of aluminum and is secured to a brass housing that connects the two heavy braided copper cables. (Aluminum and copper don’t get along but brass/aluminum and brass/copper do.)

Once the lightning rod was secured, it was on to running the braided copper wires down through the house to two 8′ (5/8″) ground rods, buried in the ground.

The electric current that is produced in a lightning strike is substantial (albeit short lived), so an excellent earth connection is required. A properly installed lightning protection system will dissipate the lightning strike safely above the house. The lightning will not travel down the copper cables as long as they are able to handle the current load. In effect, you are moving the ground up to the top of the lightning rod and the spark will terminate at the tip of the rod protecting your house from lightning damage.

A week of wonderful weather
Although the Mississippi is still above flood stage, the weather this week was sunny and mild. This week’s nature highlights included watching two bald eagles soaring just above the trees near the house, and a mating dance performed by Tom turkeys in our field. And although there were no northern lights, I did manage to capture this photo of the crescent moon along with Jupiter and Saturn.