What grade redwood beam do I have? Deflection failure.
What grade redwood beam do I have? Deflection failure.
(OP)
Hi,
Is there a simple description of the different grades of redwood available to identify what properties I should use? There are three different structural grades shown in the NDS. I have been asked to determine if an existing outdoor deck structure is adequate for public use. It is constructed of what I believe is 4"x6" rough sawn redwood. Only a few of the beams have knots. The grain is straight but not necessary close. I can't view the beam ends.
Also, if the beams fail in deflection but passes in bending and shear should there be any concern with safety? I am assumming no, although technically does this meet UBC design criteria?
Thanks for any info or direction. KMX
Is there a simple description of the different grades of redwood available to identify what properties I should use? There are three different structural grades shown in the NDS. I have been asked to determine if an existing outdoor deck structure is adequate for public use. It is constructed of what I believe is 4"x6" rough sawn redwood. Only a few of the beams have knots. The grain is straight but not necessary close. I can't view the beam ends.
Also, if the beams fail in deflection but passes in bending and shear should there be any concern with safety? I am assumming no, although technically does this meet UBC design criteria?
Thanks for any info or direction. KMX






RE: What grade redwood beam do I have? Deflection failure.
RE: What grade redwood beam do I have? Deflection failure.
You can always fall back on UBC 104.9.2. Perform a sample deflection test for your members. Back out your values for an E. Visually graded lumber has a factor of safety of about 5 on stress capacities, but the Modulus of Elasticity is pretty close. Still, those values are minimums for any grade of wood. Your really should be above the listed values anyway.
RE: What grade redwood beam do I have? Deflection failure.
Note: Remember to include the wet condition reduction factor.
RE: What grade redwood beam do I have? Deflection failure.
Have a great day.
KMX
RE: What grade redwood beam do I have? Deflection failure.
Hope this helps.
Edgeprod