Originally Posted by
Peter Quinn
The soft wood manufacturers association and their engineers have a pretty specific set of categories for the different grades of lumber, each one has its own associated span charts which are important when framing a building, not so important for building a shave horse. SPF is a combination grade that can include a lot of things, and while fir is in the name DF is almost never one of the species marked SPF. I'd say a good piece of DF is equal to a good piece of SYP, but regionally what is available may vary by species, and certain sizes are only available in a #1 common structural grade. Take 2x12, that's a serious framing member for rafters and long span joists, maybe stair stringers, they don't stock that in SPF which has much less span rating. Add engineered products into the mix, no telling what you may find locally.
Aside from all that, if you are looking for good material in framing lumber I think you are on the right track, rip down wider material that is generally of a higher quality to begin with and has less knots to cut around.
Thanks so much Peter, that and the other answers is exactly what I was looking for.
David
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