Ah, the old “hot tin roof.” It’s still common in some parts of the country to see tin roofs on older buildings. Not just tin but all sorts of metal. In some areas, metal “quonset huts” are still found all over cities and towns, too. Which leads to the big question…
What happens when you mount an antenna to a metal roof (or building?)
It’s a good question since antennas are precisely designed. Would connecting an antenna to a metal roof ruin an antenna’s carefully constructed design? Or, would the entire building become an antenna itself? Would it be a huge risk for lightning?
Well the answer is, most of the time it doesn’t mean anything. Attaching an antenna to a metal roof probably won’t improve or hurt reception. Yes, practically anything made of metal can be used as an antenna in some way. However, unless something is designed to be an antenna it will work so poorly that a “real” antenna won’t be affected by it at all.
Are there any special precautions to attaching antennas to metal roofs?
There are several. First of all if you are attaching the antenna to the actual roof you need to make sure you’re not creating holes where water can come in. It might be better to attach an antenna to the side of the building if possible, or weld on a platform for the antenna to mount to. If there’s any real concern about the metal building causing interference (there shouldn’t be) you can attach a wooden platform which will insulate the antenna from the rest of the building.
The real concern you need to have is grounding. Of course proper grounding is important no matter what sort of roof you have. Grounding can be as simple as running a copper wire from the antenna to a cold water pipe that goes underground. It can also be a little more complex. The most important thing to know is that grounding ordinances vary from city to city. What works in one city might not work elsewhere. That’s why I tend to not give really explicit instructions for grounding. I’d rather that you got the right rules from someone locally.
When you are ready to properly ground your antenna or anything else on your roof, you can get the best selection of proper grounding supplies by shopping at Solid Signal.
Will a metal roof cause any problems?
Chances are, a metal roof is going to make it hard for you to use an indoor antenna. You may also find that your cell phone doesn’t work inside, especially in a quonset hut. Those sorts of buildings are really good at deflecting incoming signals and you may find yourself missing out on important calls or texts because of it. The simple solution is to get a cellular signal booster. Cell phone signal boosters take strong signals from outside and rebroadcast them inside. It’s very possible to go from one bar to five bars instantly with a cell booster system, and they work very well in large open structures like quonset huts.
Metal roofs are also poor insulators and can make the indoors hotter or colder than a traditional roof. That’s one reason they went out of fashion, that and the noise they make when it rains and their apparent incompatibility with cats.