Square pegs

In Jack Sobon's "Historic American Timber Joinery", there are illustrations that show early carpenters used "squarish" pegs to attach rafters to plate, also in some lapped brace joinery. Can anyone tell me WHY these square pegs were used in these locations, instead of traditional octagonal pegs? Have any traditional builders out there used these "squarish" pegs for rafter-plate attachment and have you encountered any difficulties with code officals demanding lag screws or nails?
Also, I've read about the effectiveness in wedging the side cuts on joist dovetail tenons. I see no mention of this practice in "Historic Amer. Timber Joinery". Did early carpenters use wedges on their dovetail tenons? Has anyone come across any examples in their restoration/dismantling work? Hope to hear from someone, thank you.

Ron Mansour

With the exception of the tie plate connection in English Tieing Joints, dovetails in American historical timber joinery are quite uncommon, and in no way were they used for joists and purlins as in the early years of the revival. I am fortunate to have done a fair amount of of restoration work and of the few historical examples I have seen which were not part of tieing joints, none were wedged.

Lap joinery and dovetail work was more common to early English work and on some parts of the continent it remained a dominate form, namely Eastern Europe. Still I have seen nothing which suggests that lap dovetails were commonly wedged in historical framing

Square pegs were a semi common way of dealing with lift. Though I consider myself a hyper traditionalist,I would still reach for a screw because the resistance provided by it is quantifiable, and it is always a blind unseen solution.

http://www.grkfasteners.com/technical_data.htm

One place that I commonly find half dovetails (unwedged) is in common floor joist systems using +/- 2" wide rough sawn material. Typically there is at least one half dovetail close to the center of the floor joist pattern. I assume it's to keep the summer beams straight.

We just got done taking down a c1840 barn in West Virgnia near Cheat Lake. It has wedged half dovetail joints at the tie beam post connections. It also had a wall girt to the right and left of the threshing floor that had a half dovetail joint which apparently supported a tie beam which ran parrallel to a swing beam in each bent to the right and left of the threshing floor. The paired beams which no longer exist would have been 4' OC and the tie beam that sat in the dovetail appears to have been an 11x11" timber! I've never seen anything like it. Has anyone else?

Rudy R. Christian

Hi Ron, and others:

Like Rudy I have noticed a fair amount of the use of dovetail joinery where the absolute holding power of the joint needs to be maintained. As with Rudy I have run across dovetailed use in floor systems, and in rafter tie systems especially in mills where wide spans and vibrations are inherant
NH