On 4/27/2012 1:43 PM, K7LXC@aol.com wrote:
>> There is no problem with the zoning department. The building permit
> department told me I must meet Section 1609.1.1 (4.) of the 2006
> International Building Code. The structure must meet TIA/EIA-222 for a
> 3-second gust of 130 MPH. (I am only 8 miles from the Atlantic in South
> Carolina, so the area is rated for 100 MPH.)
>
> This is where your PE will come in. Of course you have to be looking
> at a tower that'll take your proposed tower and antennas and windspeed into
> account.
>
>> To comply with the neighborhood CCNR the tower must be ?attached? to our
> 2-story house.
>
> Easy. Just attach "something" to the house and to the tower. A client
> of mine used a piece of plumbing tape (the galvanized flat stuff with holes
> in it) with one end hose-clamped to the tower leg and the other end nailed
> to a roof truss. Hey - it's attached!
Don't forget to check this out with the insurance company. Mine
insisted that the tower "NOT" be attached to the house and required a
rider, particularly when you figure in labor. There are also companies
that insist the tower be connected, so this is a chance for conflict
between insurance and CCnRs
>
>> If I combine the high wind speed with the attachment
> requirement, I am initially led to the Rohn 55G Bracketed tower. However,
> I cannot find specifications from Rohn that meet the 130 MPH requirement.
> The specs for the 55G only go up to a 3-second gust of 105 MPH.
>
> Big problem. In order to get a PE stamp for something like that, they'll
> need to do a big analysis of what's in that wall and it'll probably need
> reinforcing. A fellow TowerTalkian, Tony. K1KP wrote up a nice article in QST
> some years ago on this very topic. It took LOTS of reinforcing to meet the
> building regs. Better to not use the house for a structural member.
That was a very good article and one of the main points was that house
walls are not all that strong.
A 25G might break over, depending on height and brackets but a 45G and
up would likely pull the wall over if it were not reinforced. Also the
attachment points need to be reinforced and the load spread out across
the wall instead of just on or between a pair of studs. If you can find
it that article is well worth reading. I have all the QSTs on CD, but
I don't know the year of month.
>
>> Where do I go from here? Do I need to add guy wires to the upper
> sections? If so, where do I get the specs for the guy wires? All
> suggestions would be welcomed for this new comer to towers.
>
> Even R55G will need guy wires. You need to make your tower decision
> first - either with guy wires or free-standing. Many times it's a spousal
> approval so you know what'll be acceptable and what won't. It'll be easier
> and
> somewhat cheaper to go with a guyed tower for your load and windspeed.
I'd just add that as you go up it gets expensive ...fast! Also the
difference between self supporting and guyed gets much wider with
height. Guys can be a royal PITA and particularly so if you have to use
elevated anchors like I did to clear driveways and roofs. With a 100'
45G and large antenna load my guy anchors weight about 17,000# each.
OTOH it's often difficult to find a local climber for installing and
working on guyed towers. I used to get the calls, but bout the time
social security kicked in my wife put her foot down and said it was time
for the younger guys to do the climbing although she has said nothing
about climbing my own. Now days it's what my cardiologist will let me
do. So age has or is catching up with me, particularly with a
defibrillator implanted in my chest. OTOH I was just reading about a
guy who has one that is running marathons, but I'd guess he's a bit
younger than me. <:-))
So you do want to think ahead as well.
>
> Cheers and GL,
> Steve K7LXC
> TOWER TECH
> and www.championradio.com
>
> PS - And you're off to a good start since you have already read the best
> tower book available!
> __________________________
Steve, your prejudice is showing! <:-)) But, I agree, it is a good book!
73 and good luck,
Roger (K8RI)
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