Spiral checking on green wood can be detected if you know what you're looking for (mind you, I only know soft woods, so can't speak for all species).
The checking created by lack of end seal hasn't seemed to be, in my experience, a source of structural concern, though I would never cut a frame without using it. My rule is to end seal any exposed end grain 1" and over, sloped tenons, and inside mortises.
Land Ark makes a nice product, though expensive....
No, my thoughts are those checks that were a topic of discussion on another thread recently (I'm too lazy to link to it, computer bogging down and I think you all know which one I'm talking about) where the guy's post was checked to the center of an 8x8...I saw that and wasn't so concerned; I've seen some fine, strong timbers with such checking (I was more concerned about the girt not snugged up to the housing)
So that got me thinking about this topic. We hear a lot about unsightly checking and how to avoid it (proper drying, kerfing the backsides, end seal..) but I honest to God have never heard of an actual structural failure due to extreme checking.
Spiral checking aside - that goes into the category of things to cull before the frame is cut.
Just plain old big fat check running down the length of the timber to the heart.
That's what I'm after.
I thought about posting this in the engineering forum, but wanted to see what the general consensus might be.
