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Does anyone know of a resource of wood grain orientation and heavy beams?3/7
I've been looking for a resource that goes in depth on the effect of wood grain orientation and beam strength in addition to warp, twist ect.
I remember watching a youtube video of a guy talking about how to orient your cuts on the log to get the best grain composition.
I remember him saying to avoid the heartwood, but my question is - if you have to put some heartwood in the beam what is the best place to put it?
I'd like to read more to refresh my memory as I am about to start cutting my beams and don't want to mess the cuts up on something this simple.
Be careful about taking anything from just any source. You can read anything on the internet it doesn't make it right. Same with YT.
By "heartwood" I assume you mean pith. Unless you have some big logs and can make FOHC timbers (Free Of Heart Center) then you'll need to box the hearts, meaning saw them out by centering the pith at both ends. This will allow for the least movement while drying, all other things being ideal such as no twist in the log, little run out, or crooked or even slightly swept logs etc.
Boxed heart and FOHC timbers alike demand good logs or unacceptable movement will occur almost every time. Timber selection is more important than whether or not your timber contain pith.
It does indeed sound like there is some bad info out there.
First, there is no problem with heartwood, compared to sapwood. This makes sense when you consider that all heartwood was sapwood in previous years. Now, as TT indicated, someone may have misused the term heartwood and was referring to the pith and the juvenile core. Pith is not allowed. Further, compression wood, which is common in the juvenile core (first 15 years of growth or so) is also not allowed. Then the strength is greatly reduced by having the grain at an angle...you want to saw parallel to the bark at all costs. Even then, if the cells are not perfectly vertical, but spiral, they will cause a strength loss that you can do little about.
Grain angle (also called slope of grain, SOG)
Note that this SOG results due to spiral in the tree, around knots, crooked or sweepy logs, and not sawing parallel to the bark.
Just to be complete, here is a list of the major factors affecting strength in a beam that applies to your question.
Within a piece (due log taper, log crookedness, sawing pattern)