Log Beams
Log Beams
(OP)
I have been asked to help the Amish design log beams for a log home. They are using locally cut white pine trees for the logs. Does anyone know what design values I should be using for the bending strength, shear strength, and modulus of elasticity? I thought to use the values of #3 visually graded lumber but this would fall more into the beams and stringers category. In Wisconsin, because this is ungraded lumber, we are supposed to use values for #3 material. If you look at beams and stringers there is no #3 grade. Any assistance would be much appreciated.
Thank You,
Kent.
Thank You,
Kent.






RE: Log Beams
Also, if the logs are not machine stress rated, you ususlly assume the stress level one or two grades lower than a visual rating.
Their fax is 250-547-8775, and the address is:
ILBA
PO Box 775
Lumby, BC V0E 2G0
Unfortunately, I do not have their office phone number, but you can probably Google and get that.
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Log Beams
I believe the ICC has some standards for log grading and building with logs. Where in WI are you, that they're sill cutting nice white pine? It might behoove you to have the logs graded for the better values you might be able to use.
RE: Log Beams
With all that said, I am no help to your problem. I think whatever conservative stress you end up using the size of the members will not control, it will be more about connections and stability concerns?...
RE: Log Beams
If you do need the logs graded and there is a TPI inspector in your area, they will usually come on site and do an inspection and grading of all the logs for a very reasonable price. Separate out your beams and girders which need higher values from the wall logs to make the inspection easier.
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The log span tables Mike McCann referred to by ILBA don't break items down by grade at least in my old copy. In talking to them they assumed similar to a WWPA #1 for the species even if it isn't graded.