Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

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

1" hole drilled in bottom chords of wood truss 1

Status
Not open for further replies.

lubos1984

Structural
Joined
Jul 5, 2019
Messages
65
Location
CA
Greetings to all,

An architect called me with an issue at one of the projects he's managing. Apparently the electrician drilled a 1" dia hole through the bottom chord of the trusses. The bottom chord is a 2x4 (1.5" x 3.5"). The truss manufacturer does not want to evaluate this, as their instructions are clear that no holes are allowed in the trusses.
I checked the truss calculations, and the bottom chords are loaded at about 0.35-0.55 MAX CSI, mostly at around the 0.35 mark. The architect told me he sees this often, but from my experience, I haven't come across something like this?
With less then 2" edge cover, I am concerned about splintering at these locations.
Wondered if you guys came across something like this and how you dealt with it ? The electrician did this through most of the truss bottom chords!
Thank you as usual for all your help!

Screenshot_2022-10-20_150314_m7wdzy.png
Screenshot_2022-10-20_150258_rq5gbi.png
Screenshot_2022-10-20_150227_hzg2ln.png
 
XR250 said:
To add to Koots detail, you could install another 2x4 web near the hole that intersects near a top chord panel point.

OK, this was Dumb. I believe KootK was talking about global deflection of the truss after the chord fractures. This would only work for localized chord deflection.

 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top