John, Regardless of it being a Code violation, attaching things (especially antennas) to a brick and mortar chimney, is just plain stupid. Having said that, quite a few houses over here in NZ wear the Low band VHF antenna (think 5 elements and each element over 3 ft long), as well as the mast to hold it up in the air, usually 1"-1 1/2" galvanised steel. Often these things are never guyed at all. But, the torsional forces on the bracket and the strapping are huge in high winds, not to mention the actual wind resistance of the antenna itself. Chimneys of this sort were NEVER built with the idea of having something attached to them in mind, after all it is a chimney, first and last.
Whenever I see a chimney mounted antenna (of whatever type) it just makes me think that the guy that installed it, just didn't care about his work.
I mean, I've worked on these antenna's, the soot and rubbish that comes out of the chimney, makes things even worse. There is always a better option.
BTW John, You'd never see a Ham attach any antenna worthy of the name to a chimney, it just isn't done.
As us clear from the picture, the installer arrived well prepared to hang his stuff from the chimney .... that sure looks like a store-bought strap and clamp arrangement.
Yet, I recall a few years back someone posted a link to a code that specifically addressed the issue, and the practice was clearly prohibited. I'm not able to find that link
BTW, it's been a very long time since 'chimneys' were really chimneys around here. That is, the vast majority - this is an example - are used to vent modern furnaces and gas-fired water heaters. This particular house does not have a 'fireplace' or any means to burn wood. It does, I believe, vent an oil furnace.
Indeed, some of the trendier places have completely fake 'chumneys,' tacked on for appearance alone.
Indeed, some of the trendier places have completely fake 'chimneys,' tacked on for appearance alone.
I wonder if the same prohibition would apply?
I would imagine it would, any element of a building fake or whatever would still need to conform to earthquake laws and the like. You might say "we don't get earthquakes here", no part of the world is immune from earthquakes.
I have seen a chimney (like the one you posted)fall over and through a roof, it landed on a couch, where the people were sitting an hour before, before they went to bed, it fell through the floor as well, taking the couch with it. You are really only depending on the quality of the mortar.
Last edited by Trumpy; 07/04/0904:53 AM. Reason: Typo
Here's something to cause a stir...this is what's on my own house: http://cool386.tripod.com/digital/gore1s.jpg Despite the enormous size of the VHF aerial (3m boom length) it only weighs about 3kg. The UHF aerial above weighs less. It's been up for about 14 years and despite strong winds, sometimes more than 100km/h, there's only a slight lean in the mast. One piece of advice I was given long ago was never to use water pipe for a mast with a chimney mount...the reason being that water pipe has no flexibility and transfers any stresses in high winds straight to the chimney. Gal tubing or proper aerial mast being of thinner walled construction bends slightly and absorbs the energy. It's important that the aerial mount is the weak point; not the chimney. Chimney mounts have always been very popular here but it really depends on what kind of chimney is used, and what is attached to them, as to whether they are a good or bad thing. I can't see the chimney in the pic at the start of the thread being under any stress given the small aerial and short mast. However, the particular mount does look flimsy. One really bodgie installation I worked on was a 20 foot guyed mast. The guy wires had simply been passed through holes drilled in the tiles and wrapped around the timber beneath. Not a screw eye to be seen.
TV antenna mounting kits were sold for a long time around here that specifically were made to mount on brick/masonry chimneys. They look (from memory) like what you have in the pic; metal 'corner' pcs and banding with a means to tighten.
As they were readily sold with 'old style' TV antennas, they must have been 'legal/approved' once upon a time. As TV antennas; the 1-1 1/4" pipe with the array of rods have become rare, cable a nd dishes are the norm.
That said, I'll have to keep an eye on the dishes, and look if there are any antenna kits still around.
Edit: Second look at the pic....sure looks like that's the design intent of the installed mount; now the packaging/mfg instructions come to play. Domestic mfg or China??
Monday/Tuesday, I'll ask one of the Building AHJ's about this.
I would agree this would fall under local codes. Deed restrictions are more likely to restrict this although all TV receiving antennas are exempt from deed restrictions by the feds. But, like all codes, most are only enforceable at inspection, and most antenna installations are not inspected. Like others stringing phone, and other stuff from the service mast, when it comes to the inspectors attention is when we do a service upgrade or such.
In Louisville, no permit is needed for a tv antenna, satellite dish, etc. It is a code violation to attach anything to a chimney, however. Not sure how this is enforced (probably on a case by case basis, if it is reported). Under Federal law, Direct TV discs, antennas and other radio/TV receiving devices are permitted, but must be safely erected or attached to a structure.