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RE: Posting Live Load

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The 2000 IBC requires you to design for 20 psf partition load where the partition locations are subject to change.  You can still calculate the actual partition loading when the partitions are not subject to change.  This is confirmed in the commentary as well as the fact that partition loading is considered a dead load... not a live load as indicated in the code (partition loading is included in the live load section).

A word of caution when calculating the actual partition load... in areas where walls are closely spaced, such as where closets in offices are adjacent, you can literally get 20 psf partition load, or more.  Some might argue that even with the higher partition load in that area, the live load couldn't possibly be 50 psf in that small of a space, so using 20 psf is still conservative.

Bruce D. Holcomb, PE
Butler, Rosenbury & Partners
300 S. Jefferson, Suite 505
Springfield, MO 65806-2217
ph (417) 865-6100
fax (417) 865-6102




-----Original Message-----
From: Jason Kilgore [mailto:jkilgore(--nospam--at)leok.com]
Sent: Thursday, October 09, 2003 9:20 AM
To: seaint(--nospam--at)seaint.org
Subject: Re: Posting Live Load


I have a question about the modern applicability of the 20 psf partition
load.  I've done consulting work on the remodeling of several older
structures.  Partitions in these structures were always clay tile with
plaster, CMU with plaster, wood studs with plaster, etc.  It's easy to see
how 20 psf (horizontal) or higher can be obtained.

In modern structures, almost all partitions are made from either 2x4's or
tin-foil grade metal studs (26 ga.) and gyp-board.  This weighs about 8 psf
(vertical) or less.  Assuming that the walls are spaced roughly proportional
to double their height, and counting closets, cross walls, etc., this is
around 10-12 psf (horizontal).

I'm not saying we shouldn't use the 20 psf for typical building design.  An
"open" office floor live load is 50+20=70psf, with an upper level corridor =
80psf (I normally just design the entire floor for 80psf minimum with 100psf
at elevator lobbies and exit stairs - that way the architect can move the
corridor locations 5 minutes before printing final documents and I don't
have to worry about it).

But could a more "accurate" partition load be justified in a renovation
application where you're working with an existing structure?

----
Jason Kilgore
Leigh & O'Kane, L.L.C.
jkilgore(--nospam--at)leok.com
816-444-3144
816-444-9655 (FAX)
----- Original Message ----- 
From: "richard lewis" <rlewistx(--nospam--at)juno.com>
To: <seaint(--nospam--at)seaint.org>
Sent: Thursday, October 09, 2003 8:40 AM
Subject: Re: Posting Live Load


> The reason for posting the live load is that the existing structure can't
> support the full occupancy load.  It is an existing structure.  The Owner
> does not want to spend the money to reinforce the structure.  Now, it
> actually CAN support the occupancy live load, but not the additional live
> load requirements of 20 psf for partitions.  It is going to be an open
> physical therapy area, no partitions.  The building official has agreed
> to allow the open occupancy use as long as no partitions are constructed
> and the live load is posted per the code.  I am looking for a standard
> placard layout so that I can give the owner direction in what information
> to post.
>
> The downfall of this is that in the future someone may not remember that
> no partitions are permitted.  Hopefully the sign on the wall will remind
> someone.
>
> Thanks.
>
> Rich



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