Sawing Timbers for Timber Frame
Softwood and hardwood behave differently, but in either case "box-heart" sawing tends to minimize drying movement and checking. January 11, 2007
Question
I am planning a small (12x16) garden shed as my first timber frame project. If I have logs big enough to make 18" plus cants, can I cut multiple 6" beams? Or should I cut around the cant, making 1" or 2" lumber until I have the center at 6"? I will likely be using W. oak, ash and/or tulip poplar. Maybe some red oak too. I can obviously use fewer logs if I can take more than one beam from each log. Sawing on my TimberKing B20.
Forum Responses
(Sawing and Drying Forum)
From contributor B:
If you square to multiples of 6" and then cut your 6" beams, more often than not, internal stresses in the log are released and your beam will bow like crazy as you're cutting it, as will the remaining cant. Of the species you listed, ash is the worst offender in this regard. You will be guaranteed a truer beam if you saw thinner stock around the cant.
From contributor E:
The rule I followed when I sawed white pine timbers for my timber frame house was to have no pith intersect the side of a timber. Given my log and timber sizes, the only no-pith timbers I was able to produce were 4"x6" braces. I raised the frame one year ago and see no twisting or bowing in all-pith or no-pith timbers.
From contributor B:
Pine is not nearly as reactive as the hardwoods are. There you stand a good chance of your timbers staying straight. Pine also doesn't heart check like most hardwoods.
From contributor E:
I agree with your recommendation, contributor B, but I think my observation was worth sharing. Here are some more observations. I've sawn white oak hay wagon stringers (6"x8") with the pith exposed on one face and with no pith that have stayed straight. I've also seen them bow badly.
From contributor R:
Even with 6" x 6" posts and beams, I would box heart saw them to keep them as stable and balanced as possible for shrinkage purposes as well as straightness. Then, of course, the rest of the 18" cants should become grade lumber. All that said, for a building of that size and purpose, it probably will never fall down in a tornado no matter how you saw them.
