I've worked on lightning protection systems for aircraft and large communications facilities, so believe I have a reasonable understanding of the phenomena and protection techniques. Lightning rods do work, provided they're reasonably well installed. Once you get past the marketing hype, the basic rods work just as well or better than any of these fancy things. Lightning rods at the height of a house do NOT attract lightning. If you get an attachment to the rod, it would have attached to your house had the rod not been there. There is some anecdotal evidence that high structures do attrack lighting, but nothing to support any contention that something the height of a house would. The sole purpose of a lightning rod is to minimize the chances of a fire or other physical damage due to a lighting attachment to the structure. They neither repel nor attract lighting, except over the small area that they're intended to protect. The fact that they're not required for new construction has everything to do with cost and risk management and nothing to do with whether or not they work. Lightning effects are divided into two categories, direct effects, which are the result of the passage of the actual lightning current through a structure, and indirect effects, which are the results of the transient voltages generated by the lightning strike. Most of the effects such as burned out electronics are indirect effects resulting from the transient voltage induced on power, phone, or cable conductors. That's why stuff can get damaged from a strike some distance down the line. In conclusion, yes its worth the effort to put the rods back, since you already have all the materials and there wouldn't be much labor involved. Keith
|