Oh yeah, I know they're fine when used properly. I just had an image in my mind of 3" screws holding on lathe through 2" of foam board, and then thought of how easily I can break off a screw that is hanging out that far. Even with a good stucco mix, it seemed like it's not quite enough for a good building- some of these things are designed to a hair's breadth of disaster.
"Leon"
Hey Leon, I have a neighbor with a steel stud framed house and if he holds the bedroom door open just right - he hears a radio station in his head! ;~)
Dave
I'll skirt the edge of seat-of-the-pants-diy as close as I can. I think the engineer will be cost effective both for allowing me not to expensively overbuild and for easing my drawings through the building department with that all important stamp on it.
LOL... I often wonder it all that steel would be a problem with radio or TV reception from indoor antennas.
That said, my house has an Aluminum roof that looks like Cedar Shakes. No reception problems at all.
TV would be little to no problem. FM radio would be degraded. AM radio would have the biggest problem. Would need to be near a window or have outside antenna.
FM suffers none that I remember from before and AM is fine also. Oddly the local weather radio stations do not come in at all.
The only effective RF shield is a continuous metal grid on all sides, top and bottom. It is called a Faraday cage. So, if you have a metal layer in both the subfloor and ceiling, and all of those studs are electrically connected to them and each other, and you install metal cross braces every 16", you would reduce the strength of all signals below about 300 MHz, so channels 7 to 13 might have more snow than the neighbors do, but 2-6 and FM would be much weaker. The commercial AM band would be much weaker still, which might not be a bad idea.
For any one interested in the theory, a wire mesh screen will reflect signals whose wavelength is longer than twice the size of the space between the wires. Twice 16" would be 32 inches, just less than one meter. For a wavelength of 1 meter, the frequency is 300 MHz. The reflection is not total, and the change is not instantaneous, but gradually becomes exponentially stronger as the frequency drops. At
300 MHz, the signal would be half reflected. at 150 MHz about 3/4, etc. FM broadcasts are grouped around 100 MHz, between TV channels 6 and 7. AM is way down at 1MHz.On the other hand, a steel building sitting on the ground pretty much blocks everything.
Bob McConnell N2SPP
As an interesting aside, my window shaker AC unit in the bedroom plays music very softly when it's running. Took quite a few times getting up to see which radio had been left on before I tried turning that off, and the quiet tunes stopped. Must be some kind of wierd thing with the fan spinning inside a farraday cage, or my brain is just filling in the static, though it doesn't happen with a white noise machine. I figure it's probably not me, though- it's usually stuff I don't listen to, and comes complete with commericals.
Could that be a neighbors radio playing? If you are letting outside air mix, the sound could be coming in when the unit is on and its out side air door is open.
Have you done anything to try and fix the problem? ~ maybe an extra grounding wire attached to the case exterior or something?
Could be, but I'm in an awful quiet neighborhood- and the outside air vent stays closed to keep the humidity out. Probably some oddball combo of directional placement, circuit boards and dental fillings all aligned "just so".
Nah- it's just weird. By the time my head hits the pillow, I'm done for most nights, so it's really not a problem. Working 12+ hours in the sun on a day when you *need* a/c is better than a sleeping pill- the neighbors could be blasting heavy metal next to the window, and it wouldn't matter a bit.
Have something to add? Share your thoughts — no account required.
Ask the community — no account required