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RE: Cost Analysis

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As a former iron worker in the Kansas City area, I would not be happy with
the 0.6C 28 ga form deck.  It is a pain.  It will flatten out and smash down
as you walk on it.  Seams come apart with normal foot traffic.  And if you
require a fire rated floor, it must be sprayed.

In my prior life as the slave of developers in the Kansas City area where
the buck rules over all, the least costly was a blend of your 2 systems.
Use 1 1/2" composite fire rated deck on bar joists at about 5' to 6'
spacing.  The bar joists can bear on joist girders or WF beams depending on
what you do with the HVAC.  You only have to spray the joists and girders
not the slab, if you use a thick enough concrete cover.  The Vulcraft book
has a list of the rated systems.  The heavier bar joists will not require a
screen.  The fire proofing is a major cost item.  This system minimizes the
piece count, field work, and fire proofing.  You have to be careful on the
joist depth if it drives the floor to floor height.  You will also need to
assess the cost of cladding if the floor to floor height is pushed.  When
you do your cost comparison, factor in the welded studs if you consider
composite WF girders.  They will run from $0.75 to $1.00 each.

Call Bratton Steel they have done this exercise many times.  They even used
to do the fireproofing in the Kansas City area.

Regards,
Harold O. Sprague


> -----Original Message-----
> From:	Jason Kilgore [SMTP:jkilgore(--nospam--at)leok.com]
> Sent:	Thursday, March 22, 2001 9:35 AM
> To:	seaint(--nospam--at)seaint.org
> Subject:	Cost Analysis
> 
> We currently have a disagreement in our office about relative pricing of
> different floor construction methods for office-building type usage (fire-
> proofed or not).  Most of our work is in the Kansas City area, where
> unions
> rule supreme and labor costs are high.
> 
> Both of the owners of my company are adamant about one of the methods,
> several of the younger engineers disagree (but are out-ranked, so the
> owners'
> method is used).
> 
> If the disagreement continues, I'm going to do a mock building design
> using
> the two methods and have a few construction companies price it.
> 
> Here are the two sides of the issue (very generalized).  Any comments?
> 
> 
> One side:
> Use WF girders, steel bar joists at 2'0" - 2'6" o.c., with light-gage form
> deck (0.6C28).
> Advantages:  Easier installation, lighter & easier-to-handle pieces,
> cheaper
> deck, no shoring.
> Disadvantages:  Short spans require heavier joists for fire-rating, fire-
> proofing more labor-intensive (requires wrapping each joist in mesh),
> more pieces to install and fire-proof
> 
> 
> Other side:
> Use WF girders, WF beams at 6'0"-8'0" o.c., heavier composite decking.
> Advantages: Far fewer pieces, WF beams usually meet min. sizes for fire-
> ratings, easier and faster to fire-proof.
> Disadvantages: Pieces are larger, installation more difficult, deck far
> more
> expensive, sometimes requires shoring for casting.
> 
> 
> 
> ----
> Jason W. Kilgore, P.E.
> Leigh & O'Kane, L.L.C.
> jkilgore(--nospam--at)leok.com
> (816) 444-3144
> *   site at: http://www.seaint.org 
>