Top and Bottom Chord Splice Location

[RFreund]

After doing some research it appears that most pre-fab trusses locate their splices for the top chord and bottom chord away from panel points. My questions is:

1. Where should the splice be put for a top or bottom chord?
2. Why?

Thanks

EIT

 

[MiketheEngineer]

In a typical triangular shaped roof truss the max axial forces are in the panels at the heels (bearing). So you don't want to splice in those panels.

Then the splice location is usually at the 1/4 point of a panel +/- 12'' or so based on the belief that the chord is acting like a continuous beam over the panel points and this location has minimal moment. Analysis and testing tends to bear this out in most situations. This does not preclude splicing at a joint - just makes more sense and easier to analyze.

Flat trusses have max axial forces at the center panels.

 

[woodman88]

With the current capabilities of computers and software, you can analysis the splice at any location. The truss manufacturer will place them at the most convenient location for their inventory and truss building practices.

Garth Dreger PE
AZ Phoenix area

 

[RFreund]

Makes sense.
Thanks guys.

EIT