TJI joists 1

[awa5114]

I'm using the following resource (

http://www.techsupport.weyerhaeuser...-15-25-35-35X-55-DF-SP-Literature-1997-1985-)

to check some TJI joists with point loads. The only problem: this manufacturer's "span tables" are all heavily based on uniform loads. Also they don't really show how the capacities are derived for these uniform loads. How does one determine capacities and deflections for these properietary joists with loading beyond the scope of the span tables, including point loads?

 

[CBSE]

Download their proprietary software or buy the NDS manuals and do the calcs.

 

[CANPRO]

see link below. scroll to the bottom of the page. there is a section called "Design and Specification". Click the link for your region and look through the PDF. You will find moment/shear resistance and EI for different joists.

http://www.woodbywy.com/trus-joist/tji-joists/

 

[XR250]

FYI, Boise Cascade is supposed to be bringing their software to the cloud soon. That is great since their last automatic update does not run on XP and I cannot revert - bastards!

 

[awa5114]

Download their proprietary software or buy the NDS manuals and do the calcs.

You can't use NDS for these things. Open up your NDS book (2013 edition) page 50.

"Reference design values for prefabricated wood I-joists shall be obtained from prefabricated I-joist manufacturer's literature or code evaluation reports"

 

[mike20793]

I don't see where it says you can't use the NDS to check them. The chapter you're referencing is for TJI joists.

I'm sure you could use an equivalent uniform load that reproduces your max moment and max shear and then compare to the table.

 

[focuseng]

The NDS is a design standard. The manufacturer produces E, I, Fv, Fb values for you to use to this standard. Usually found in a pamphlet called the "Design Guide" or look up the ICC report if in doubt. also mentioned though is the use of the iLevel software "Forte" for analysing I-joist by Weyerhaeuser. Each reputable manufacturer publishes tools and info for you to use. I can't remember the last time I actually looked at a span table...

______________
MAP

 

[medeek]

To check TJI joists I use their software Forte, its actually quite good, you can even do other lumber types as well.

A confused student is a good student.
Nathaniel P. Wilkerson, PE

http://www.medeek.com

 

[peal724]

I've used Forte by Weyerhaoaususuer, and the one provided by RedBuilt, but I find that BCCalc provided by Boise Cascade to be the best. I like the way you can organize the project and it's interface seems better to me.