Check out the APA website. They have some literature on plywood-lumber box beams that probably covers the subject.
Eric R. Ober, PE, SE
Associate
Holbert Apple Associates
3423 Olney-Laytonsville Rd., Ste. 6
Olney, Maryland 20832
(301)570-1460 (Phone)
(301)570-1462 (Fax)
-----Original Message-----
From: Bill Allen [mailto:t.w.allen@cox.net]
Sent: Thursday, January 15, 2009 1:51 PM
To: seaint@seaint.org
Subject: Lateral Stability of a Box Beam ?
I have a situation requiring two beams, approximately 12" apart spanning about 27 feet. They aren't supporting much more than their own weight, but I'm concerned that if I just use the span as the unbraced length, the beams are going to be very large.
I would like to put plywood top and bottom to increase the effective lateral torsional strength. Is there a good reference in determining the capacity of such an assembly in wood?
Thank you,
T. William (Bill) Allen, S.E.
Consulting Structural Engineers
V (949) 248-8588 •