Even with xray vision we couldn't find those WMDs!!!!

Respectfully, I would appreciate if politics didn't sour our discussion. That's a subject that can easily get out of hand and upset people, especially on the internet where it is difficult to tell whether someone is simply joking or insulting another.

Now, on topic (at least sort of)

First, I need to retract a previous statement. I was in error on my comment about scissor trusses. I had another system in mind when I said that, and got the two confused. There is an older style of truss joinery employed during the Anglo Saxon, Norman, and transition periods that relies heavily on half dovetails, because there are members that are designed to at times be in tension.

The subject of the development of joinery is interesting. One of the appendices to English Historic Carpentry contains a discussion of the development of the unwithdrawable lap joint, it discusses it as a sophisticated, important joint. It is a joint that serves a purpose that the mortise and tenon cannot. And the mortise and tenon functions in ways that this brace cannot.

I think we do well to remember this joint, and what its advantages are.

Lapped dovetails also provide an advantage in that they can be inserted after other framing members have been assembled and pegged.

And as a side note, are there enough of you that would like to see some of my conclusions regarding traditional Swiss (Lower Bernese) carpentry to justify writing it up and posting it on these forums? (I don't have a website, guess I am behind the times. Which is OK I guess for an Anabaptist, right?)

Hi DHL,

I thought that you might enjoy this picture of the Master at work taken at Cressing Temple, Essex, England in January 1993.

Cecil Hewett at Cressing Temple Jan 1993

I do not appear in the picture. There are 2 possible explanations.

Regards

Ken Hume

Fully housed bracing can be also inserted after raising with the use of a filler block under the brace mortice, the mortice just needs to be a little longer.

Tim

I know what you mean there, Tim, but I've never been a fan of that method really.

There's a 100 year old barn directly behind my house that has braces inserted into extra long mortises, and I just don't like the whole system that well having seen it first hand.

Personally, I like the look of a refined entry lap dovetail brace, and some of the examples I have seen in my study of Swiss buildings make this joint quite attractive. The Swiss have a tendency to make everything both wonderfully functional and elegantly beautiful.

That said, I realize that the mortise and tenon has certain advantages over the lap dovetail. It really depends on what the joint is designed to put up with as much as anything. Obviously if your joint is not expected to be under heavy tension then you do not need to engineer it for tension, and a lap joint in compression might have more of a tendency to 'pop out' of its housing.