Wednesday, November 11, 2009

RE: EMT Properties

Szuchan, this publication is recommending EMT for bracing cloud ceilings
http://www.armstrong.com/common/c2002/content/files/56394.pdf

I have been using 250S162 studs for bracing ceilings or just for compression
posts when used with splayed wires. USG has has their Donn Compression post,
but I have never spec'd it.
http://www.usg.com/USG_Marketing_Content/usg.com/web_files/Documents/Install
ation_and_Appl_Guides/SC2497_Seismic_Technical_Guide_Compression_Posts.pdf

-----Original Message-----
From: Szuchuan Chang [mailto:szuchuan@gmail.com]
Sent: Sunday, June 21, 2009 12:22 AM
To: seaint@seaint.org
Subject: Re: EMT Properties

About a year ago, I designed some non-structural seismic ceiling support for
an auditorium. If you study the recommended details by the Armstrong or
City of Los Angeles, you will find the EMT are no longer recommended by
them. Ray Shreenan said that he is using it for tensions only which may be
alright. But ceiling braces takes both tension and compression forces.

I would agree with Jim Gataz, "Even if I knew the properties of the tubes,
from what I've seen of the connectors for EMT." The way the tube walls are
welded together and the difficulties of making that through bolt connection
works made me give up on the use of EMT. I also try to use the light weight
HSS tubes. Again, the connections are impossible to control.

If you have a workable connections, please share with us who have to design
the ceiling supports.

Thanks

Szuchan


On Tue, Jun 9, 2009 at 9:37 PM, Gerard Madden, SE<gmse4603@gmail.com> wrote:
> Actually, this is used all the time in ceilings
>
> -gm
>
> On Tue, Jun 9, 2009 at 5:59 PM, Bill Polhemus <bill@polhemus.cc> wrote:
>>
>> Sounds like a contractor has ton of the stuff and wants to use it in
>> lieu of stuff he'd have to buy.
>> When all you have is a hammer...
>>
>> William L. Polhemus, Jr. P.E.
>> Via iPhone 3G
>> On Jun 9, 2009, at 6:26 AM, Jim Getaz <jgetaz@shockeyprecast.com> wrote:
>>
>>         Ray,
>>                 Even if I knew the properties of the tubes, from what
>> I've seen of the connectors for EMT, I'm not sure I'd want to be
>> involved in using it structurally.
>>         Jim Getaz
>>
>

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