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RE: Glulam Beams

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=>I have a few questions:
=>
=>1. Has anyone found 24F-V8 DF/DF glulam beams 5.125 wide by
=>12 and 15 inches deep to be special order items, i.e. long lead items?

I have found that V8 is a longer lead time than V4. I have also found that
24F-V5 (2400 psi both positive and negative bending) is a fairly short lead
time, if the camber you specify is within limits (see below). But, spend the
time and call around your local lumber yards and ask THEM what is readily in
stock. Usually a certain size range and they can usually provide a camber
chart (see below). No, they won't think you are stoopid for asking the
question.

=>2. What is your experience with camber? Do you typically
=>specify camber?

Always, but I try to specify/design a beam such that the camber is equal to
or less than R=2,000 ft. or 1,600 ft. Lumber yards can produce a chart for
you or you can make one up (span vs. camber based on R=2,000 ft. or 1,600
ft.).

=>3. I have a project with simple span window headers and one
=>case with the glulam header extending beyond the exterior
=>building line as a cantilever to support a roofed entry. I
=>spec'd a 24F-V8 cambered to be installed upside down so
=>deflections would be minimized and be apparent under
=>deadloads. What is your opinions about this installation.

This is a case where I have specified a "negative" camber (i.e., camber up).
Make this instruction clear on the plans. If you Glu-lam is going outside,
make sure it is protected VERY WELL against moisture!!

=>4. I used the same spec. 24F-V8 and cambered for the simple
=>span headers, 5 feet maximum span, and was informed that
=>camber is never used for this type of installation. Opinions, please.

It is difficult for framers to frame above a cambered beam. Imagine trying
to place a straight wall over a curved beam. A real PITA.


Regards,

Bill Allen, S.E.
ALLEN DESIGNS
Laguna Niguel, CA