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#7947 - 09/17/01 02:47 PM drawboring v. comealongs, panels

Would appreciate thoughts on the following:
1) Which is better, drawboring or using comealongs? Argument for drawboring: It will keep the joint tight as timbers shrink. Arg. for drilling through when joints are drawn tight with comealongs: they are as tight as with drawboring. What's right, and which will be better in preventing joint failure? Which will loosen less? Which will split tenons less?
2)How does this sound for a built-up wall: drywall, vapor barrier, 2x4s 24" oc nailed horizontally across posts, extruded polystyrene mounted tight between 2xs, 2" of isocyanurate on outside of 2xs, strapped by 1x3s into place, mosture barrier, 1" diagonal boards nailed into 2xs and screwed or spiked through into posts, shingles. Total thickness to outside of boards, 8 5/8". Spikes or screws would have to be 2"-3" longer to penetrate posts. 4 3/8" of the thickness would be supported by a 2x12, leaving 4 1/4" (isocyanurate, strapping, boards, shingles)to be supported by 2" of XPS on outside of foundation. Too much unsupported?
3) Does RF drying actually dry to the centers of the timbers sufficient to eliminate shrinking? Thanks for any assistance.--Al

#7948 - 12/29/01 09:26 PM Re: drawboring v. comealongs, panels

Hello asqualloff:
I would like to reply to the drawbore question--
When I was in doubt about such questions I would examine the actual works of traditional timberframers from long ago. Following their techniques you make no (major) mistakes. I must admit though that they made errors like anyone else and they were not all the best timberframers or hewers. In reviewing many timberframes I have noticed errors covered up but in most cases the frames were still strong and true.
They had no comealongs, and the drawbore technique proved to be one of the best methods to tighten up a mortise and tenon joint (done properly). Take an 1.25" oak peg that bows 1\8" to 3\16" in the width of the timber and then add in some case 2 or three pegs in heavy barn framing, and you have tons and I mean tons of force that you could not obtain with a 1 to 2 ton comealong.
I hope that I have made a case for the draw bore technique that has been tried and proven over the centuries.
To add to that it is so much easier to drift in the draw bore pins than to set up a complicated pulling action with comealongs not to say anything about the damage to the exterior of the timber's corners and faces.
The Northern Hewer


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