×
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

Can you combine glulams and DF-L boards for a post?

Can you combine glulams and DF-L boards for a post?

Can you combine glulams and DF-L boards for a post?

(OP)
I am trying to help a friend out with his 2-story barn structure which consists/upported by braced frames in one direction. The braced frame problem I have consists of a 6x12 DF-L No.1 girder, supported by a post on each side, and the girder is further supported by 6x6 knee-braces connecting the girder and post on each side. The post was originally designed to be a composite member (a 6x10 with a 2x12 nailed to each side for additional support/inertia). This worked for a 23' total span with a live load of 40 psf and a dead load of 14.2 psf. It turns out that the girder supporting the second floor must support 125 psf instead of 40 psf because it's an agricultural building and the 2nd story is considered "light storage" according to officials and the UBC 97. So now we have to redesign the posts. What may work, and please correct me if I'm totally wrong, for the posts, I want to use a 5-1/2" x 10-1/2" glulam. The glulam alone is close, but I need additional support (need more moment capacity because the knee-brace from the girder is bending the post). My question (finally) is , can I attach/nail a 2x12 DF-L to each side of this glulam and reap the benefit of those boards providing the required extra moment I need? The 2x12's also hide the fact I am using a glulam, which the architect is not fond of seeing. I'm trying to shy away from larger glu-lam members, and the 5-1/2' width matches perfectly for the plate connection with the 6x6 knee braces.
Can I even use a glu-lam beam as a post in the first place? And will the fact the the glulam and the boards have different f'b not allow me to count this a composit post? Sorry for the long winded question. If any one help me, I'd greatly appreciate your answers or ideas?

RE: Can you combine glulams and DF-L boards for a post?

arcoiris74,

I've never used a glulam as a compression member although I guess it would work well at least in terms of load capacity. You probably should check with the manufacturer to see if they would have any concerns about the possibility of the plys separating when loaded in compression on the end of the member. Another consideration would be the environment. Because this is an agricultural application, I'm guessing that it may be exposed to moisture which could be an issue.

RE: Can you combine glulams and DF-L boards for a post?

http://www.trusjoist.com/PDFFiles/3400.pdf#search='Parallam%20PSL'
Try this website, I have used these Parallam PSL posts in quite a few applications.  They are specifically made to be used as posts.

RE: Can you combine glulams and DF-L boards for a post?

If you combine the members with different E values you should transform them based on the relative E values.  Long ago we designed flitch beams (a steel plate sandwiched between two 2x's) in this manner for heavily loaded headers.  As noted by Redfish, the paralam or other LVL works well in highly loaded locations as well.

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