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1. Lumber Dimensions. Tabulated design values are applicable to lumber that will be used under dry conditions such as in most covered structures. For 2" to 4" thick lumber the DRY dressed sizes shall be used (see table 1A) regardless of the moisture content at the time of manufacture or use. In calculating design values, the natural gain in strength and stiffness that occurs as lumber dries has been taken into consideration as well as the reduction in in size that occurs when unseasoned lumber shrinks. The gain in load carrying capacity due to increased strength and stiffness resulting from drying more than offsets the design effect of size reduction due to shrinkage.
If'n i'm understanding you properly. Nail a 2x6 under the DF RC floor joist to the top sill plate and the stud, then nail a 2x6 vertically to the stud under the horizontal 2x6. Good idea on the 2x6, but will possibly still use 2x4 the goes vertically. It's all doug fir, so the strength should be ok. Have to have room for wiring and related in the wall behind it. That would work fine. I was thinking of just a vertical 2x6, no horizontal nailer. Nail the 2x6 flatways to the studs so that it sits under the joist. The joist extends across the 2x6 and alongside of the 2x4 stud and is attached to it. But either will work if I'm understanding you correctly.As to roll, that's what the rim joist is for isn't? Maybe I'm getting my terms mixed up? But we will be putting blocking in between them and sheet rock will run up to the blocking and the bottom of the joist.I was proposing between the 2x4 studs run 4x12 blocking between joist and stud. Yes a rim restrains the joist from rolling by end connection, a solid block wedged between will help while things are drying and also provide fire blocking. Just make sure flame cannot get from wall to floor or from floor to floor, no chimneys.So just want to make sure on the green joist face depth (12" as cut) vs the dried rim joist (11.5ish). Your saying to notch the bottom of the green 2x12 a 1/4" where it'll sit on the sill plate and leave a 1/4" above the dried rim joist for shrink? What I described then doesn't need a bottom notch simply set the top of the green joist about 1/4" above the top of the dry one.Any advantage to using a green rim joist instead of a dried smaller one?Shrinkage would be closer to the same.As to the posts. Thinking to set them above ground and on a green treated piece of wood or on some type of vapor barrier and pour the crete around them. This eliminates the wood from sucking up moisture from the soil, but being in the crete gives me stability. Set on the masonry piers gives me little hold down and we are in tornado alley.That works when new but if the bottom decays in 5 years you are back to an uplift problem. If you set a steel knife plate in the concrete or a rated connector with a standoff to get the bottom up you'll have the best of both worlds.Thanks again
I've read the original post and can't say I really understand it all. Pics are worth 1000 words. I will say this though: It's fine to timberframe green. I wouldn't have a problem with a floor joist that it 8x8 or 8x10 green, but such non symmetrical dimensions like 3x12 or 4x12 may crown quite a bit while drying. That will screw up a floor or ceiling attached to it. If you want joists like that, or even 2x material, it needs to be dry before install. I know that Doug fir is radio frequency KD'd from some suppliers. If it's your own wood that you're milling, I'd mill it oversize and let it air dry for a year, then put it in conditioned space for 6 months to get a lot of the movement out of it, then check the MC and see where it's at. When you use symmetrical sticks green, and they must be boxed heart, they are more likely to dry more symmetrically. They will check on one face primarily and have some movement, but less likely to crown/bow. Even so, if you are using timbers as floor joists, you typically want to give them time if you can to see if they do move, a year if you can. Then you can correct for that initial movement.I installed DF T&G 2x flooring in a loft without checking the MC back in 2016. Well it shrank and we have some significant gaps now. And it was nailed down, so taking it up would destroy it. Unfortunately dimensional DF that this flooring started from is allowed to be KD down to 20% and sold as KD. Hardwood is typically dried down to 6-8%. So you have to beware and check the MC and make sure it's down to at least 8% before installation on any T&G.
Dave is right FOHC beams won't check as much as boxed heart beams.As to why they stay straight, Dave's Doug-Fir, could be the quality of the tree and the amount or not of sap wood as Mark has mentioned. It could be the type of wood. Wood is very variable, and each tree is different, depending on where it grew, on a hill side or on flat ground, for example.My experiment log may have grown on a hill side and therefore have some tension and compression wood in it. Or the bowed timber could have more sapwood in it. It's hard to say, why one my 9 o'clock timber bent and the 3 o'clock timber didn't. And I've had boxed heart timbers bend. Jim
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