LVL wood beam column
LVL wood beam column
(OP)
I am checking a design done by others, for an LVL column ("4 ply built up 2"x6" Versa-Lam studs") that occurs in the exterior wall and extends from first floor to peak of an arched roof. The column is about 20.5 feet long. It carries both roof snow laod and about 7 foot width of tributary wind wind load. Can I use the procedures, factors and equations in Canadian Standards Association (CSA) Standard O86 Engineering Design in Wood", if I get from the manufacturer the basic properties like compressive strength fc, modulus of elasticity, etc., or must I go to the manufacturer for him to check it or perhaps they have tables, although the tables may not fit the conditions for this particular building.
If I do use CSA O86, one of my questions is what should I use for the size factor Kzb for bending? Same as for that size of lumber if it were sawn timber (which would be a 1.4 factor in bending for a 2x6), or would it be 1.0?
If I do use CSA O86, one of my questions is what should I use for the size factor Kzb for bending? Same as for that size of lumber if it were sawn timber (which would be a 1.4 factor in bending for a 2x6), or would it be 1.0?






RE: LVL wood beam column
I would check deflection first - you may have a problem there. I usually use 2x8 wall or a tube or flitch beam in these situations.
RE: LVL wood beam column
RE: LVL wood beam column
This is because a #1 2x12 is a lesser quality lumber than a #1 2x6. This is why ripping visible graded lumber is not allowed under the NDS. But grade bending allowable in the NDS is based on the grade of a 2x12. So a size factor is used to increase the bending allowable of the smaller sizes such as the 2x6.
Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.
RE: LVL wood beam column
Might want to add a p-delta moment to the beam-column as well due to the large deflection.
RE: LVL wood beam column
So to be perfectly clear, can I calculate the strength of LVL lumber in accordance with the CSA Standard for sawn lumber, but with the size facor set to 1.0, and the permissible stresses and modulus of elasticity as per the LVL manufacturer's data? Or are strength determinations basically in accordance with manufacturer's published load/wind tables?
also, do different manufacturers have different recommendations for permissible stresses?
RE: LVL wood beam column
I've never thought of the size factor for lvl's but woodman makes a good point. but since you get to increase the strength for a 2x6 because the quality is better why wouldn't you get to increase the strength of a LVL post? Unless the allowable stresses provided by the manufacturer's already account for the accuracy of their material specifications.
RE: LVL wood beam column
RE: LVL wood beam column
Lessons learned:
1. Contact the manufacturer at the start when designing or checking proprietary w2ood products;
2. Be careful in downloading stuff from the internet; it may not deal with the product used in your country, or be geared to the design methods used in your country;
3. Similar comment with respect to advice from this forum.
RE: LVL wood beam column
Are you the same person, or working together? It makes it confusing when comments from two "handles" seem to be from the same source.
RE: LVL wood beam column
RE: LVL wood beam column