Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Cost Comparison (Steel) question

Cost Comparison (Steel) question

Cost Comparison (Steel) question

Steel framed building - typical bay size is 20'x20'.

Which is more economical for a roof framing system-

A.  1 1/2" roof deck on W10x12 at 6'-8" o.c.
B.  3" roof deck on W12x14 at 10'-0" o.c.

I think the 3" roof deck would be a better solution, even though 3" roof deck would cost more.  You have fewer beams, (even though they are slightly heavier), fewer connections.  Heavier roof deck would take more labor to install, but I'd imagine that would be at least offset by installing fewer beams.

Anyone have any thoughts or similar experience?


RE: Cost Comparison (Steel) question


I posed a very similiar question to a fabricator and erector (teamed up for a design build project) one time. 30' x 42' bays, with eithier beams at 10' spacing and 3" deck, or beams at 6' with 1 1/2" deck.

Their response was that the costs would be virtually identical @ approximately $5.00/SF

However, substituting open-web joists for the beams reduces the cost to about $4.00/SF.

Obviously, those costs are very project specific, and may not be representative of your situation, but it does give an idea of the magintude of savings that can be realized from using joists.  

RE: Cost Comparison (Steel) question

One thing to consider, If the owner is going to need an FM rating for their insurance, there are no 3" metal roof decks that have an FM rating.  This alone would cause the use of 1.50" deck to be the right choice.

RE: Cost Comparison (Steel) question

In these areas... the 1-1/2" deck is generally more economical and 6'8" +/- is generally the max span for 0.030 CNT.  It can be used for about 7' max, depending on loading, but is very bouncy for this span...


Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close