Hi folks,
Great discussion! I was on the Germany frame tour during the heat of this topic, so was not aware I could even be of help. Looks to me like the replies have done an excellent job of covering the topic, but I do have a little input. Are you surprised?
It is quite true that braces are traditionally flush to one face of the post or beam in American frames as well as late English and German frames. The face they are flush to is nearly always the "layout face" which I have also heard called the "fair" face and "reference" face. This being the case, the layout for the mortice from the face is most often 2" to 2" (4x4 braces) and occassionally 1 1/2" to 1 1/2" (3x5 braces)or "shnaf shnaf" in Sobonese.
As a rule of thumb braces are cut with tenons flush to one face and always used in pairs which react in compression to lateral loading. In my opinion braces cause trouble when designed to work in tension. One interesting tenon layout you will find on old frames has a small notch cut at the back end of the tenon on the short side of the brace. I had heard theories that this was to allow them to "lock" into the mortice. I beleive rather it was a time saver since the mortice would require drilling five holes instead of four for 3x5 braces, since the diagonal was around 7" depending on the milling of the brace. It was much easier to notch the tenons than to drill 25% more holes.
Pegging of braces seems less depended on stock size than I had once thought. I saw frames in Southern Germany where braces are made from 6x6 stock and larger and yet only sport stub tenons with no pegs. In Northern Germany every stick is pegged in the frame including a horizontal 6x6 that was just over 4" long in one building!
I don't believe we are likely to find a difinitive answer to this question. In my studies of frames in Ohio, German frames have unpegged braces while English frames have pegged braces...usually. It is true that you rarely find pegged 4x4 braces, but I think the relationship is based more on taste, style or whatever you want to call it. We peg braces in our frames because the bents stay stiff during the raising and we like them to stay where we put them, but that doesn't mean it's the right way to do it.
So much for my three cents. Glad to be home again, but Germany was a wonderland of timber frame buildings and well worth taking some time off to study.
Now, would anyone like to talk about carpenter's marks?
Rudy
