I am new to the world of timber framing. I attended the stone house work shop what a wonderfull experince. I leared a lot but there is so much to learn. There is a whole lot more than meets the eye. The people that were there were wonderfull and very helpfull they took time to answer your questions and show you what to do but it was more then I could digest in one work shop. Any one who is interested in timber framing is a fool if they do not attend the guild work shops. I can not say enouph for the people or the guild.
The question. how do you determine the length of the brace mortise pocket? If I were to use culled 4x6s which are under sized maybe 3.5 or 3.75 by something between 5.5 and 6 would I use the hyp of triangle formed by the thick side (5.5-6 side) If not how would I determine the length.

Another question deals with snap line and out of sq timbers. I think I understand the snap line as to getting lines perpendicular to the referance face. I hung a sq on refence face down by the ref. side, measured over a know distance (2 in) made a mark and movered over another know distance (6 in) on both ends from the same face and edge. This allowed me to have paralell tenon lines on the end of timber. How do I get mortise cuts to be perpendiculal to the tenon so it will slip in strait. The timber I am cutting on is a 8x8 and about a 1/4 inch out of sq. but it is not twisted just sawn that way and semi dry about 2 years old.
Thanks

Here's a graphic for the brace:

Don't apply the body of the square to the edge of the timber, align it with the snapped line, the body running the length of the timber with the snapped line. Draw the mortice line along the tongue, perpendicular to the snapped line.

Not sure I read the question right or interpreted it correct.

Are you snapping two parallel lines on the same face?

I would have the brace stock re sawn to make it all more uniform. One possibility. Or scribe it. Or use square rule to reduce the waste side/inside to the ideal tenon. So, size all your tenons to 3" using 1-1/2" shoulder and 1-1/2" tenon/mortice. Make all your mortices the size of the largest know width stock, 6" and all the smaller ones will fit for sure as well as the big.

May be I did not explain it well. The timber is laying East and West with the referance face up and the referance side facing South. I hang the framing sq on the referance face with the blade hanging down on the south side. I mark off 2 inches from the cornerS off the bladeS over to the north on the referance face and again 6 inches from the corners of the sq. I do this on both the referance face and the bottom side On the bottom side I measure over from the edge of the blade I never move the sq while I do this. Then I go to other end and repeat the process There are marks 2 inches and 6 inches over from the referance edge on the refeance face and 2 and 6 on the bottom from a imajinary point out in space if you want to call it. but it would be perpendicular to the refeance corner. I then snap a line from these points. I then have one side of the tenon and one side of a mortise pocket if I am right so far I can conect the tenon points at the end of the timber and the tenon should be perpendicular to the referance face.

Why are you marking the 6" point? I can see the 2" points and the snapped line, at which you would align the 2" body of the square, and draw the other side of the mortice or tenon, at 4", respectively.

You may also need to chase a 2" mark down the north face, covering all four sides.

In square rule layout you have to allow some space for irregular sized timbers. We don't know for sure what the mortise pocket length will be unless we label each brace to each pocket and cut them to fit exact.
To eliminate this problem we make the pocket over sized a bit on all of them so that any brace can go into any pocket. That's the value in using square rule layout.

As Mike's picture shows the length of the housing for the brace is 8 1/2". We'll lay it out and cut it to be 8 5/8" or more so that any width brace would fit in and not bind up.

Here is a drawing showing the longer mortise and housing:



Here is a picture showing it in real wood:



Does that help?

Jim Rogers

And in Jim's real wood example, a snapped line is visible. Also of note in the drawn picture you see the dotted line which is the snapped line, it is on this line the length of the brace is measured.

This snapped line is not necessarily the same as when snapping lines on the big timber.

Why would you measure to the dotted line at the inside corner of the housing? Doesn't make sense to me. I always treat the long edge as reference.

Measure to the edge of the ideal timber size. Layout for the 1/2" or ??" housing. Proceed from there. Do the same on the receiving timber. Layout the housing depth from reference. That inside corner will be in the same location.

Mike, it truly does make a difference. I believe it is chased back to how the mortices are laid out in square rule, in part and more specific to the brace stock itself. The snapped line you see on Jim's brace is the referencing point on the brace stock not the edge of the timber, therefore you can not use it to measure on. In the case Jim presented that is the reason for the line. It is skinning a cat in a different way. today I laid out two long roof braces, running from the foot of one principal rafter to the top of the next, funky braces, the ends are swapped, anyway, I laid it out from the edge as you suggest. It is not my typical method, I use the same method Jim shows.

Open your view points up and see both worlds. Perhaps Jim can comment on that as well?

The "ideal timber size" is the snapped line and it meets the ideal timber within the post at the housing on the post, as proof.

The snapped line could be 1/2" , 3/4 or 1" or for that matter 0" in from the edge of the timber, it does not matter as long as the brace length is measured along the line. You will see some over hang if it is larger than 3/8" due to the housings/reductions being 1/2" deep.

This snapped line method also allows for layout of naturally curved brace stock. or brace stock that has dried and is not straight. Blessed you must be Mike, for having straight brace stock.

I do not understand the chased back means A word that is I do not understand