Hank,
Agreed. I was just trying to point out that the blanket statement,"an
exterior wall of a house was never meant to take a lateral load", is wrong.
It certainly would depend on how well the bracket transfers the load into
the structure and where it does it.
Wes
"At 10:18 PM 1/15/01 -0800, Lonberg, Hank wrote:
> Wes:
>
>Remember though the exterior walls are designed to take the load spread out
>over their full area, that is how the wind load is actually applies. The
>problem with bracket loads is that they are applied in a relatively small
>area and typically exterior walls are not designed for this.
>
>Hank Lonberg P.E. / KR7X
>
>
>-----Original Message-----
>From: Wes and Linda
>To: Mike Murphy; towertalk@contesting.com
>Sent: 1/15/01 8:33 PM
>Subject: Re: [TowerTalk] Tower Concerns continued
>
>At 02:45 PM 1/15/01 -0500, Mike Murphy wrote:
>>I have been watching this post for some time. I can't help but wonder
>if we
>>are forgetting that an exterior wall of a house was never meant to take
>a
>>lateral load, especially from 30 or 40 feet of tower hanging over it.
>An
>>exterior wall is meant to support the roof, not a tower pushing and
>pulling
>>on it.
>
>You better damn betcha that the exterior wall of a house is designed to
>take lateral loads. If you're worried about that (XXX) MPH wind blowing
>against the tower and antennas what do you think is going on with the
>flat
>wall of the house. The wall typically has a lot more square footage
>that
>any tower/antenna and is a "flat plate" with a higher drag coefficient
>that
>the round stuff in the antenna.
>
>Furthermore, in a good windstorm, the walls are probably holding the
>roof
>down, not up.
>
>I'm not advocating bracketing to a house. I would never do it to mine
>and I
>built it and it's way over engineered, but it happens to be stuccoed and
>I
>have enough cracking problems.
>
>Nevertheless, don't forget the story of the three little pigs.
>
>Wes N7WS
>
>
>
>
>>
>>I have put up, taken down and serviced a number of towers. And it
>simply
>>amazes me what hams "get away" with. It may work for a while, maybe
>>forever. But if you need 110 MPH wind survival, put up a free standing
>>tower that is designed for it. Otherwise you are playing with fire,
>not to
>>mention taking a chance on pulling down part of your house.
>>
>>Michael Murphy - KD8OK
>>
>>
>>>The bracket is over designed as much as I could. Where it attaches to
>the
>>>house it is 5' long and it has three bolts that go through vertical
>2x4. I
>>>have this backed up with a horizontal 2x4. All of this including the
>bolts
>>>are stainless steel. Several locals have agreed that this is done
>properly
>>>and I believe it to be a better bracket then the one Rohn uses in
>their
>>>bracketed towers.
>>
>>
>>
>>--
>>FAQ on WWW: http://www.contesting.com/FAQ/towertalk
>>Submissions: towertalk@contesting.com
>>Administrative requests: towertalk-REQUEST@contesting.com
>>Problems: owner-towertalk@contesting.com
>>
>>
>>
>
>
>--
>FAQ on WWW: http://www.contesting.com/FAQ/towertalk
>Submissions: towertalk@contesting.com
>Administrative requests: towertalk-REQUEST@contesting.com
>Problems: owner-towertalk@contesting.com
>
>
--
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