Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

RE: Roof Deck Personnel loading

[Subject Prev][Subject Next][Thread Prev][Thread Next]
I have always found it interesting that construction workers envisioned by
the SDI who work on top of roof deck weigh 200 pounds.  But the construction
workers who work on floor composite or non-composite deck weigh only 150
pounds.  I don't know of any specifications that require a construction
worker weight loss when working on lower floors.

As a former iron worker, I recall smashing the flutes of 26 Ga. and 28 Ga.
form deck quite easily, and at that time I weighed about 160 pounds.  We
would always walk on the deck over the bar joists.  Although it is not as
common as it was in the past, light gauge non-composite form deck can cause
construction problems.  After I became an engineer, I increased the gauge on
my projects from that indicated in the SDI and manufacturer's literature
because my iron working buddies would have killed me.  There was no science,
and no engineering.  It was simply self preservation.

Regards,
Harold O. Sprague

> -----Original Message-----
> From:	Ron Hill [SMTP:ronhill(--nospam--at)hillce.com]
> Sent:	Saturday, September 21, 2002 11:22 PM
> To:	seaint(--nospam--at)seaint.org
> Subject:	RE: Roof Deck Personnel loading
> 
> Stan,
> 
> It is possible to design for 20 psf live load and fail to provide
> strength for personnel.
> 
> In the Vulcraft  catalog, a 1.5F, 22 gage deck (Intermediate Rib)  spans
> 7' and  supports 30 psf ( 10 dl + 20 ll).
> 
> In their specifications they note that for a 200 lb concentrated load on
> the deck to provide a maximum of 4'-6" span.
> 
> My concern is that not all deck designs provide the table for
> concentrated loads and therefore there are roofs in place that may be a
> problem for personnel.
> 
> 
> Ronald A. Hill, P.E.
> HILL Consulting Engineering
> PO BOX 26525
> Birmingham, Alabama 35260 USA
> Phone: 205-823-4784
> FAX: 205-823-4145
> email: ronhill(--nospam--at)hillce.com
> http:\\www.hillce.com
> 
> 
> -----Original Message-----
> From: sscholl2(--nospam--at)juno.com [mailto:sscholl2(--nospam--at)juno.com] 
> Sent: Friday, September 20, 2002 10:06 PM
> To: seaint(--nospam--at)seaint.org
> Cc: seaint(--nospam--at)seaint.org
> Subject: Re: Roof Deck Personnel loading
> 
> It is perfectly safe to walk on a 20psf roof (which is what we have in
> CA). It is not safe to send an army up there or to stack a lot of
> material close together.
> 
> Stan Scholl, P.E.
> Laguna Beach, CA
> 
> On Fri, 20 Sep 2002 12:01:47 -0500 "Ron Hill" <ronhill(--nospam--at)hillce.com>
> writes:
> > Roger,
> > 
> > You are Correct for uniform loading.  My question is how we tell an
> > owner it is safe to walk on the roof.
> > 
> > Scenario 1:   An employee weighs 200 pounds and can easily stand 
> > with in
> > the 12" square tile on the office floor.  This computes as 200 psf.  
> > The
> > owner asks "It is safe to walk on a 30 psf roof????"
> > 
> > Scenario 2:  The metal roof deck spans 4 ' between the joists.  A - 
> > 200
> > pound man are standing on a bay 12" wide between the joists.  
> > Another
> > 200 pound man walks up and stands beside him to look at the AC unit.
> > Their weight on the deck bay is now 400/1/4 = 100 psf.  The 
> > combinations
> > are endless.
> > 
> > I have not seen any information in SDI that can document that the
> > loading is safe.
> > 
> > 
> > 
> > Ronald A. Hill, P.E.
> > HILL Consulting Engineering
> > PO BOX 26525
> > Birmingham, Alabama 35260 USA
> > Phone: 205-823-4784
> > FAX: 205-823-4145
> > email: ronhill(--nospam--at)hillce.com
> > http:\\www.hillce.com
> > 
> > 
> > -----Original Message-----
> > From: Roger Turk [mailto:73527.1356(--nospam--at)compuserve.com] 
> > Sent: Friday, September 20, 2002 10:29 AM
> > To: seaint(--nospam--at)seaint.org
> > Subject: Roof Deck Personnel loading
> > 
> > Ron,
> > 
> > I think that the 30 psf roof load relates more to stacking roofing
> > materials 
> > and the effect of snow than it does to personnel loading.
> > 
> > For personnel to come close to the 30 psf loading, you would have to
> > have 180 
> > pound people standing 2.5 feet apart over the entire considered 
> > area.
> > In 
> > other words, it would be quite congested.
> > 
> > A. Roger Turk, P.E.(Structural)
> > Tucson, Arizona
> > 
> > Ron Hill wrote:
> > 
> > . > I have a question about roof decks and 30 psf live loading.  I 
> > have
> > . > looked in the codes and in the manufacturers data concerning
> > permissible
> > . > personnel loading on roof decks and can not find anything. 
> > 
> > . > When we design a roof for a uniform live load of 30 psf, how 
> > does
> > that
> > . > correlate to how many men can stand in one area on the roof at 
> > any
> > given
> > . > time??
> > 
> > . > Ronald A. Hill, P.E.
> > 

******* ****** ******* ******** ******* ******* ******* ***
*   Read list FAQ at: http://www.seaint.org/list_FAQ.asp
* 
*   This email was sent to you via Structural Engineers 
*   Association of Southern California (SEAOSC) server. To 
*   subscribe (no fee) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you 
*   send to the list is public domain and may be re-posted 
*   without your permission. Make sure you visit our web 
*   site at: http://www.seaint.org 
******* ****** ****** ****** ******* ****** ****** ********