Max span for floor joists


rfcomm2k
 Share

Recommended Posts

I have determined that the max span I need for part of my building without support is 30' This requires 14" wood I beams placed 12" o.c.

 

I just looked at the framing drawing for it and see that the first floor has all the joists running from foundation wall to foundation wall with no apparent support shown.

 

If I upgrade to CAx8, will this be done automatically, or do I need to manually add posts and support beams beneath the joists?

Link to comment
Share on other sites

This should be a standard disclaimer:  Home Designer and Chief Architect products do not perform ANY engineering calculations, structural or otherwise, and prior to construction, all designs created with them should be professionally reviewed by an experienced and licensed professional engineer if not otherwise required to be so by local governing bodies.

 

As rfcomm2k has discovered, you can easily draw things in this software that should not be able to, or even cannot, build in the real world.  I think very highly of this software's capabilities to provide visual information about a particular design and changes thereto.  But this software is for creating virtual models, and some of which may not necessarily have real world equivalents.  Case in point, you can quite easily model a floating roof with no wall or foundation supports; not exactly something that can be built.

 

In the interest of fair disclosure, yes I am a licensed professional engineer, and no, I am not and do not intend to ever be in the business of reviewing user-created HD or CA plans.  Just throwing that out there ... :)

 

Good luck. :)

Link to comment
Share on other sites

Elovia and most of the rest of us are NOT State Licensed Structural Engineers and as such if any of us answer any Engineering questions we could be fined for doing so. In Texas it is a $5,000.00 file levied by the State Architectural Board, such policies vary from state to state but anywhere in the USA, that is a 'NO-NO". Hire a real Engineer and them them as agents of your State do their jobs.

 

DJP

Link to comment
Share on other sites

  • 1 month later...

I have determined that the max span I need for part of my building without support is 30' This requires 14" wood I beams placed 12" o.c.

 

I just looked at the framing drawing for it and see that the first floor has all the joists running from foundation wall to foundation wall with no apparent support shown.

 

If I upgrade to CAx8, will this be done automatically, or do I need to manually add posts and support beams beneath the joists?

 

From my experience, 14" I-Joists 12" O.C. won't work on that span unless it's attic space or something.

 

On a wide open floor with no bearing walls or roof bracing on this joist in the span, It would take like a 3.5" flanged 16" I-joist 12" O.C. If your foundation isn't a basement, I'd put a girder with piers through there like a crawlspace. Then you could use 11-7/8" I-Joists 16" O.C. if there's no load bearing walls on the joists. I'm no engineer but this should work.

Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
 Share