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In length normal wood doesn't shrink appreciably. In width 1/4 to 3/8" from green to in service moisture content, that varies considerably. Where you chose to fix the connection plays a large role in the direction the shrinkage moves things. For instance with the post at a door if you pin the post closer to the jamb the post will stay tight to the jamb but the opposite face will move towards the pin. In the case of your plates pin them low, close to the bearing notch so that the notch will carry the load rather than the pin. When bolting, bolt low, near the bearing and do not space bolts more than about 5" apart across the face width of a piece of wood to avoid drawing the wood apart and splitting it between bolts.
Where you chose to fix the connection plays a large role in the direction the shrinkage moves things. For instance with the post at a door if you pin the post closer to the jamb the post will stay tight to the jamb but the opposite face will move towards the pin. In the case of your plates pin them low, close to the bearing notch so that the notch will carry the load rather than the pin. When bolting, bolt low, near the bearing and do not space bolts more than about 5" apart across the face width of a piece of wood to avoid drawing the wood apart and splitting it between bolts.
Whoops, we're on top of each other but I'll post the reply to the post Q and then read this latest post.If I'm understanding the question right. Imagine a 12x12 post standing on a slab. If I bolt a piece of angle iron to the floor on the door jamb side of the post and bolt the upright leg of the angle to the post, as the post shrinks the door jamb side of the post will not move. As the post shrinks the far side will move towards the point of attachment, the angle clip.Same thing if you bolt a horizontal beam to a notched post. If I put the bolt or peg through the beam into the post down low on the beam, close to the notch the beam will bear on the notch as it shrinks. If I put the pin at the top of the beam and into the post, as the beam shrinks it will lift off the notch and hang from the bolt. The beam will likely split at the bolt. That is shown in pics in the second link in my post above. Scroll through that and think about what they are showing, good stuff for post and beam or timberframe builders.
I'll let you walk through the rafter check, talk me through it like I did above and I'll spot you.Also try 3.5x11.25 dougfir @4' oc.The easiest way to do a cathedral ceiling is a structural ridgebeam with rafters hanging from it.Sounds like a 20' span? 18' tributary width... half of each rafter is bearing on the eave wall, half is bearing on the ridge x 30 psf=540 lbs per lineal foot on the ridge. Glulam table here;http://www.aitc-glulam.org/pdf/Capacity/DF_26.PDFLooks like a 5-1/8x13.5 would work.Then 2x T&G decking. That looks good, is readily available and pretty fast to dry in. Does that solve it or do you want to keep going with the above?
Started by Dstrnad on Timber Framing/Log construction
Started by Winter86 on Timber Framing/Log construction
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Started by mart on Timber Framing/Log construction