Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations SDETERS on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Timber Compression Strength 4

Status
Not open for further replies.

zero1238

Structural
Oct 6, 2017
74
I have a scenario where I am taking out a load bearing wall above a basement and installing a steel beam. I plan on supporting the steel beam with steel columns but the issue I have is that the steel columns coming down to footings in the basement are directly in line with the existing timber beam in the basement supporting the floor above so I’d be landing 13kips and a steel column on a triple (3) 2x10 drop beam. I’m concerned about crushing/shear and I also don’t like supporting a stronger material (steel column) with a weaker material (wood beam), even if I plan on putting a new column beneath the wood beam where the steel column lands on top. Any thoughts/resources on this?
 
Replies continue below

Recommended for you

Check the bearing strength of the wood.
 
Big, thick bearing plates top and bottom
 
American Wood Council National Design Specification (NDS), Section 3.4.3.1, Table 4.3.1, and the Supplement Table 4A/4B should provide you will all that you need for this.
 
I’ve heard of engineers jacketing they beam in steel on all four sides between the loaded column above and the support column below. Has anyone ever done/seen something like that before?
 
I have not, that seems fairly overkill in a residential application.
 
As ChorasDen wrote, look in NDS for the compressive strength perpendicular to the grain for the species of the triple 2x10. All things considered, much will depend on how much contact area you can provide from the bottom of the column to the top of the triple and at the triple bearing on the wall (presumably).
For example, IF the triple is made of Southern Pine (you're in Florida I think) THEN the F perp is 565 psi (going from memory). At 4 1/2" wide you'll need a little over 5" of bearing (4 1/2" x 5 1/8" approx.) to avoid crushing the wood.
Is that available to you? I might want to add some additional blocking next to the triple (if that is practical), just to help spread the load out more

I assume you are not supporting masonry with the steel column. If you are, there are other considerations.
 
That's a good idea. I'm going to look back through the NDS but I like the idea of using a larger bearing plate at the base. Thank you for the feedback. And I'm actually in NJ.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor