×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

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!
  • Students Click Here

*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

Jobs

Why interior bearing wall?

Why interior bearing wall?

Why interior bearing wall?

(OP)
I am the structural EOR for this custom home and I was a bit irritated when the truss mfr said it was necessary to provide an interior bearing wall (the clouded one running north-south about center of the 40 foot span trusses of the main roof).

The girder truss labeled GT8 (north-south on the lower right hand corner) may have been overloaded w/o the interior bearing wall, but wouldn't it have been much easier to leave the interior wall as non-bearing and make GT7 3-pt brg, and GT8 3- or 4- pt brg?

I don't understand why truss designers rarely, if ever, call on the phone to discuss these things. I purposely left my name and number for them, and now we are post-plans check and is too late to do anything except go with the scheme as clouded and redlined (see attached).

Can I get a second opinion from any truss designers here, please?

RE: Why interior bearing wall?

AELLC:
RE: Truss designers and manuf’ers.... 1.) Their design software is pretty efficient, and designs what they, their equipment and stock materials can build, to meet the local bldg. codes, one hopes and assumes. 2.) 95% of their customers wouldn’t know how to answer a question if they did call with one, they would shrug their shoulders and say ‘you guys know best, that’s why we farmed the design out. 3.) they should design what your drawings showed, did you show where you wanted bearing points or bearing walls, or girder trusses, etc. 4.) they can do some pretty amazing things with very complex (Arch./owner ego induced) roof systems. 5.) on these complex roof systems, or if you do want something other than their first choice, you most certainly should show this on your drawings and reserve the right to red line their shop drawing before they start manuf’ing, so... you are not stuck with their design. I’ve actually had pretty good luck getting them to do what I wanted, but you do have to communicate this to them.

You most certainly should check their shop drawing on these complicated roof systems, as the EOR you are ultimately responsible when something goes wrong. At least you’ll spend a lot of time and money proving you are not at fault. I’m not suggesting you should check every simple truss design they spit out, but you better pay some attention to the large/heavy/special trusses, their connections and their bearing locations. Do they seem reasonable, are the reactions about right, do the special connections look right, do you have a continuous load path to the foundations for those large reactions. I’ve been involved in a number of cases where the contractor never looked at the shop drawings, except for the erection and truss numbering drawings. And, the heavily loaded trusses had a couple extra studs under their bearing ends, as an afterthought, but their was no special column arrangement on the next floor down, or it was sitting out in the middle of a light TJI joist, with nothing under it on the next level down.

RE: Why interior bearing wall?

Could you really make the walls work for interior bearing on the girders? Plf loads to an wall sounds more workable.

Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.

RE: Why interior bearing wall?

(OP)
Garth,
Girders with interior bearings usually result in 6x4 or 8x4 posts in a 2x4 wall. All those short walls underneath GT8 would make it possible to convince the Architect to make one 2x6 studs if an 8x4 post didn't work.

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!


Resources