# Do houses have lightning rods anymore? **URL:** \ **Category:** Factual Questions\ **Created:** [December 26, 2009, 9:19am UTC](https://boards.straightdope.com/t/do-houses-have-lightning-rods-anymore/522615 "2009-12-26T09:19:35Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![needscoffee](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/needscoffee/32/1076_2.png) [@needscoffee](https://boards.straightdope.com/u/needscoffee)\ **Post date:** [December 26, 2009, 9:19am UTC](https://boards.straightdope.com/t/do-houses-have-lightning-rods-anymore/522615/1 "2009-12-26T09:19:35Z")
Looking around my big-city neighborhood, none of the houses have visible lightning rods. Why not? ---
**Author:** ![Arkcon](https://avatars.discourse-cdn.com/v4/letter/a/96bed5/32.png) [@Arkcon](https://boards.straightdope.com/u/Arkcon)\ **Post date:** [December 26, 2009, 2:07pm UTC](https://boards.straightdope.com/t/do-houses-have-lightning-rods-anymore/522615/2 "2009-12-26T14:07:00Z")
Well, the Master himself has a number of articles on the subject, and there’s some evidence that they don’t work at all. > **[Do lightning rods really work?](https://www.straightdope.com/21343426/do-lightning-rods-really-work)** It’s a little bit of a hairy topic. First of, Franklin’s theory of how they worked was wrong. Others have improved on the theory, and method, for example Tesla. There are other methods to protect a building, using terrain, and even pine trees apparently. > **[Lightning rod | United States](https://en.wikipedia.org/wiki/Lightning_rod#United_States)** > > In what later became the United States, the pointed lightning rod conductor, also called a lightning attractor or Franklin rod, was invented by Benjamin Franklin in 1752 as part of his groundbreaking exploration of electricity. Although not the first to suggest a correlation between electricity and lightning, Franklin was the first to propose a workable system for testing his hypothesis. Franklin speculated that, with an iron rod sharpened to a point, "The electrical fire would, I think, be dr If they’re not installed properly, they do more harm than good. And that’s a lot of power – the Mythbusters have pointed out, we can’t generate, store, and release synthetic lightning with the same amps that the sky can generate, so any testing is hard to do. > **[Lightning rod | Lightning conductors and grounding precautions](https://en.wikipedia.org/wiki/Lightning_rod#Lightning_conductors_and_grounding_precautions)** > > Ideally, the underground part of the assembly should reside in an area of high ground conductivity. If the underground cable is able to resist corrosion well, it can be covered in salt to improve its electrical connection with the ground. While the electrical resistance of the lightning conductor between the air terminal and the Earth is of significant concern, the inductive reactance of the conductor could be more important. For this reason, the down conductor route is kept short, and any curves... Then again, people have been putting spikes on top of buildings since forever, and those buildings (anecdotally) survive better. My wag – we have fire departments and fire insurance nowadays. Lightning rods were more important in olden times. ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [December 26, 2009, 2:26pm UTC](https://boards.straightdope.com/t/do-houses-have-lightning-rods-anymore/522615/3 "2009-12-26T14:26:05Z")
Houses are grounded. Every house has a copper stake driven into the ground near the electric meter. That should transfer some of the electrical power, from a strike, into the ground. That’s still not the same as having a lighting rod on the roof. It seems those are only found on taller buildings. ---
**Author:** ![blondebear](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/blondebear/32/1022_2.png) [@blondebear](https://boards.straightdope.com/u/blondebear)\ **Post date:** [December 26, 2009, 3:04pm UTC](https://boards.straightdope.com/t/do-houses-have-lightning-rods-anymore/522615/4 "2009-12-26T15:04:33Z")
I was surprised to discover that the data center where I work has a lightning rod. The facility engineer took us on a tour of the roof and made a point of showing it to us. It makes sense, considering the nature of our business, but it wasn’t something I expected to see. ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [December 26, 2009, 3:21pm UTC](https://boards.straightdope.com/t/do-houses-have-lightning-rods-anymore/522615/5 "2009-12-26T15:21:17Z")
Most houses have a metal sewer vent that acts as ground. This is what TV antennas were grounded to. If not for this ground, the static electricity of a nearby lightening bolt would be picked up and transmitted to the TV. The effect would be that of a cheap sci-fi movie with sparks shooting off the back of the set. Experienced that at my parent’s house when the grounding strap corroded off. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [December 26, 2009, 4:52pm UTC](https://boards.straightdope.com/t/do-houses-have-lightning-rods-anymore/522615/6 "2009-12-26T16:52:18Z")
> [@Magiver](#): > > Most houses have a metal sewer vent that acts as ground. Not many houses built in the last 40 years - they’re pretty much all PVC. ---
**Author:** ![Shagnasty](https://avatars.discourse-cdn.com/v4/letter/s/9dc877/32.png) [@Shagnasty](https://boards.straightdope.com/u/Shagnasty)\ **Post date:** [December 26, 2009, 5:48pm UTC](https://boards.straightdope.com/t/do-houses-have-lightning-rods-anymore/522615/7 "2009-12-26T17:48:47Z")
> [@Magiver](#): > > The effect would be that of a cheap sci-fi movie with sparks shooting off the back of the set. Experienced that at my parent’s house when the grounding strap corroded off. That happened to us when I was young. A lightning bolt either hit the house directly or a nearby power line. It blew out almost all of the appliances in the house but we were watching TV at the time and it basically just exploded sending sparks everywhere and almost caught on fire itself. Our nanny was watching us at the time just sat on the couch and did nothing. She said “When lightning hits, I sits”. It was some of the best advice I had heard in a while. I woke up to the sounds of a massive thunderstorm this summer that ended in a circa 1814 church right down the street being partially destroyed. I wish something like a lighting rod could have saved it the steeple. I hate lightning. It is pure evil. [http://www.boston.com/news/local/breaking\_news/2009/07/lightning\_strik\_1.html](http://www.boston.com/news/local/breaking_news/2009/07/lightning_strik_1.html) ---
**Author:** ![boytyperanma](https://avatars.discourse-cdn.com/v4/letter/b/4491bb/32.png) [@boytyperanma](https://boards.straightdope.com/u/boytyperanma)\ **Post date:** [December 26, 2009, 7:04pm UTC](https://boards.straightdope.com/t/do-houses-have-lightning-rods-anymore/522615/8 "2009-12-26T19:04:27Z")
> [@needscoffee](#): > > Looking around my big-city neighborhood, none of the houses have visible lightning rods. Why not? If the houses are in a big city neighborhood odds are they don’t need to worry about having their own lightning rods. They have those big city skyscrapers nearby to soak up the lightning blows. I occasionally deal with houses that have been hit by lightning. Some of the more expensive hilltop homes that get hit frequently have installed lightning rod type grounding. It does help with some strikes but even on those homes occasionally I’m there after a serious strike that still resulted in something exploding(in my case the usually the water pump) ---
**Author:** ![Baffle](https://avatars.discourse-cdn.com/v4/letter/b/dec6dc/32.png) [@Baffle](https://boards.straightdope.com/u/Baffle)\ **Post date:** [December 28, 2009, 11:01pm UTC](https://boards.straightdope.com/t/do-houses-have-lightning-rods-anymore/522615/9 "2009-12-28T23:01:22Z")
We have a series of lightning rods on the barn; the farm is at the top of a hill and is the highest ground in about a mile’s radius. I’m actually not sure if there’s a lightning rod on the house, but they are definitely in use in rural areas of Ontario. ---
**Author:** ![NicePete](https://avatars.discourse-cdn.com/v4/letter/n/ee7513/32.png) [@NicePete](https://boards.straightdope.com/u/NicePete)\ **Post date:** [December 29, 2009, 4:44pm UTC](https://boards.straightdope.com/t/do-houses-have-lightning-rods-anymore/522615/10 "2009-12-29T16:44:28Z")
We have a couple on our 105 year old farmhouse. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [December 29, 2009, 4:51pm UTC](https://boards.straightdope.com/t/do-houses-have-lightning-rods-anymore/522615/11 "2009-12-29T16:51:09Z")
wood or any part of your house looks equally good as the earth to a lightning bolt that has just traveled many miles through air which is not very conductive. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [December 29, 2009, 5:30pm UTC](https://boards.straightdope.com/t/do-houses-have-lightning-rods-anymore/522615/12 "2009-12-29T17:30:40Z")
They certainly do still use them – my brother-in-law’s business is largely installing lightning rods. Older theories about lightning rods are certainly wrong, but I’m surprised at suggestions that the rods don’t work. It’s not as if they haven’t been tested a _lot_ by places like General Electric. They’ve even built lightning generators to produce lightning for such tests. Plots of lightning strikes around rod-protected structures using these devices show that properly-installed rods do, indeed, prevent the lightning from striking nearby structures or the ground – by taking the lightning hit themselves, rather than by dissipating electrical charge. (See Peter Viemeister’s **The Lightning Book** for plots of such strikes [http://www.amazon.com/exec/obidos/ASIN/0262720043/ref=nosim/weisstein-20](http://www.amazon.com/exec/obidos/ASIN/0262720043/ref=nosim/weisstein-20)) The Wikipedia page tallks about the difficulty of locating lightning strikes in the Real World ([Lightning rod - Wikipedia](http://en.wikipedia.org/wiki/Lightning_rod) ), but these laboratory scaled-down tests do indeed show protection. As for the thing about sharpened points, let me point out once again one of my favorite physics papers, _The Lightning Rod Fallacy_ by Richard Price and Ronald Crowley in American Journal of Physics Vol. 53 (9) 843-848, September 1985. The usual statements about the electric field being strongest where the radius of curvature is tightest on a conductor and shown to be incorrect and misleading, and they give copious counter-examples to the basic case and to attempts to refine the statement. Lots of EM theory fun for all. ---
**Author:** ![Ignatz](https://avatars.discourse-cdn.com/v4/letter/i/3be4f8/32.png) [@Ignatz](https://boards.straightdope.com/u/Ignatz)\ **Post date:** [December 30, 2009, 1:28am UTC](https://boards.straightdope.com/t/do-houses-have-lightning-rods-anymore/522615/13 "2009-12-30T01:28:58Z")
Lots of church steeples have them. Seems to be a lack of faith. ---
**Author:** ![needscoffee](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/needscoffee/32/1076_2.png) [@needscoffee](https://boards.straightdope.com/u/needscoffee)\ **Post date:** [December 30, 2009, 2:47am UTC](https://boards.straightdope.com/t/do-houses-have-lightning-rods-anymore/522615/14 "2009-12-30T02:47:23Z")
> [@Ignatz](#): > > Lots of church steeples have them. Seems to be a lack of faith. It’s really bad advertising when God smites your church with lightning.