Glulam beams and grade

[awa5114]

Are glulam beams typically a certain grade? Or can they come in any of the following grades?

DF SS
DF#1 & Btr
DF#1
DF#2
2.0E Parallam
1.9E Microllam LVL
24F-V4
24F-V8
20F-V12
20F-V13

 

[jayrod12]

As far as glulams (and I'm talking actually glulam beams, not LSL, LVL, PSL etc) typically come in either SPF or Dfir around here in the 12c-E and 16c-E (respectively for columns) and a range of flexural strengths from 20f-E to 24f-E in many different configurations, i.e. balanced, unbalanced for beams.

 

[awa5114]

What do those numbers and letters represent? 20f-E, 12c-E etc?

 

[jayrod12]

The strengths. 12c-E is a column grade for SPF. 20f-E is an SPF beam grade.

Give your applicable code a read and they should describe all of this for you. Not sure where's you're situated, but in N.A. either the NDS (in the U.S.) or the Wood Design Manual (In Canada) would have an adequate description that would answer these basic questions.

 

[Sawbux]

The number & F are typically the bending stress for the beam. The other items listed are for solid sawn timber or other engineered lumber, not glulam.

 

[JAE]

These values:
24F-V4
24F-V8
20F-V12
20F-V13

are typical set specifications for glue lam beams and columns. In the US, you can find these in the AF&PA NDS specification, or in the AITC manual.



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[awa5114]

Thats quite a few to choose from. I'm involved in a project for which there are no real as-built drawings. How can I determine or make an assumption for the wood grade based on say the project location?

 

[jayrod12]

Try contacting local glulam suppliers. They generally don't ship them too far and in my experience there isn't a large amount of turnover in that industry.

 

[sandman21]

The glulam should have markings on the side which will have the information you need.

 

[Triangled]

OP:
only these in your list are glued-laminated specs
24F-V4
24F-V8
20F-V12
20F-V13
the first two digits followed by "F" are shorthand for the bending strength or the main tension face in loading perpendicular to the laminations. The "V" indicates visually graded lumber. The combined designation "V4, V8, V12, V13..." etcetera is the combination symbol. The combination is a precise code-ratified specification that indicates the variety of strength requirements for each of the various laminations of a glulam beam. An inner lamination of a beam designed primarily for bending may have significantly less capacity than the outer lamination. The compression face lamination of a 24-V4 beam may have only 50% tension in bending capacity of the tension face.
Contact apa-ews or any good wood book for full information.

 

[Triangled]

it seems rather likely,
assuming your building's locality is in southern California based upon your other thread, which locks in the geography,
and assuming your beams are supporting SSI joists as based in your other thread, which locks in the era,
your glulam beams are DF 24F-V4 and DF 24F-V8