Thursday, August 2, 2007

RE: Glu-Lam beam with Steel Channel calc

I believe that if you get the AITC technical note on glulam laminations, you can get a rather good idea of the grade of the material in the middle laminations.  It has been a little while since I look at it, so I don't recall how specific it gets.
 
Regards,
 
Scott
Adrian, MI
-----Original Message-----
From: Jerry Coombs [mailto:JCoombs@carollo.com]
Sent: Thursday, August 02, 2007 2:43 PM
To: seaint@seaint.org
Subject: RE: Glu-Lam beam with Steel Channel calc

Exactly.  Those are "filler" layers, and are generally low-grade.  Reality is, you don't know what they  are. 
RE: loading, with the proper number of connectors, you can ensure that they will be loaded "simultaneously", but you still won't know what the wood contribution is.

>>> On 8/2/2007 at 1:30 PM, "Josh Comfort" <jcomfort@ggbse.com> wrote:
When you say "taking off a few laminations" it sounds to me as if you are proposing cutting off the lower portion of the existing glulam beam, is that correct?  If so, you'll want to be sure to take into account the new grade of lumber that you have at the tension face of your beam when figuring F'b.
-----Original Message-----
From: erik gibbs [mailto:erik.gibbs@gmail.com]
Sent: Thursday, August 02, 2007 10:59 AM
To: seaint@seaint.org
Subject: Glu-Lam beam with Steel Channel calc

I previously posted a question about a plan check question for out of plane loading on a shearwall and to all that posted I thank you, it cleared up any questions that I had.
 
Now to my new question. I have an existing 5-1/8" x 15"  Glu Lam beam that spans 21'-6" in a garage of an existing residence. The owner wants to turn this into a flush beam, which means taking a few laminations off and sistering a new beam next to the GLB. I want to use a steel channel, C10x15.3, but this section, when checked in bending fails under the full load. Also the GLB fails under the full load when checked by itself. My question is how would you check/calc both beams in a rational method, instead of just saying that the GLB takes 50% of the load and the steel beam takes the other 50%?
 
Thanks
 
Erik Gibbs