Hi. I am hoping someone can comment on drawboring. I am designing and building my first post and beam structure, a 14x10 woodshed. Should I plan on drawboring every mortise and tenon joint? Is there and order which you should do it? For instance can you drawbore the braces as well as the plates and crossbeams or would you do one and not the other? Also, what pegs should be used when drawboring? Tapered, chamfered, octagonal? And what pegs should you use when not drawboring. Thank you for your help.

Hi Astc,

Some of this is specific to the type of timber framing you are doing. I would also note, within the realm of the craft, there is much diversity. You very well may get a number of variable answers to this question.



Short tenons, like on braces do not require draw boring and in general, braces only work in compression and don't even need to be pegged if the frame is cut well. Braces do respond to wedging in some styles.




This could depend on style and system of raising so is hard to give a definitive answer.



You do not draw bore braces, there is not enough relish in the tenon.


Dry hard wood is typical (and probably the best) but there is plenty of heart pine, and other conifer as well found in vintage frames and other styles.

Tapered, chamfered, octagonal?

Tapered is about the only "yes" to this answer but the rest is subjective.

I don't think I am understanding this question? The pegs down change whether you draw bore or not.

Hope this helped.

I must point out that Jay often comments as if his answers are the end and final result. Go right ahead and draw bore you brace stock or not. Sure it can be assembled without pegging but I like pegged bracing, if for nothing else it aids in assembling. I also have mostly switched over to assembling the frame work and pricking the tenons, pulling the joinery apart and drawboring from there. Wonderful not to have fouled up peg holes.

There are three basic methods of drawboring that I am aware of:

1. Layout on the horses and bore as part of joint cutting process. Pros are efficiency of effort. Cons are the absolute lack of fault tolerance.

2. Tim's method of assemble on the deck, prick offset center, disassemble, drill and reassemble and drive pegs. Pros are easy control of frame dimensions with fault tolerance. Cons are related to efficiency ideals.

3. Point to the joint drilling. The mortised member is predrilled, The frame is assembled and strapped tight, the bore is drilled with slope. Wild card method, not consistent for me to endorse.

Roger, great concise break down, I have to work on that for speed.

Tim, I am sorry if I offended you in someway, I though my entry was rather neutral in general. My answers are not the end and final result of anything, just the reflection of 35 years of studying, restoring and cutting frames. Considering what I do for a living though, for the duration I have done it, and the amount of failed pegged braces I have seen, my entry was germane, appropriate and true. It was not subjective at all.

I actually though of you last month and some of our conversation we have had around pegs. One of the Amish crews I work with are seeing a number of frames in certain areas of Ohio that use a smaller peg for braces, with keen understanding (circa date after 1830) that peg bracing came about as a facilitation method for raising, nothing more. On rare occasion, we have found barns (one house so far) that used a large metal nail (spike) to serve this purpose. Minnesota, Michigan and Wisconsin vintage barns thus fare studied and taken down, do not have pegged braces and some are, what appears to be wedges added later.

Regards,

jay

Not offended at all Jay. I actually chuckled a little as I sent that one off. It could just be me and the way I read post.

I am moving to almost full scribe in my shop and as such I find pricking the joinery a simple step to make, it all comes together without any worries. What I am finding after years of square rule is scribing is not more time consuming if weighing the tidy results it yields, it has many benefits.

I may try snap line square rule some time.

Unpegged bracing is far and few between in my neck of the woods, I can recall only one barn and that was in western Maine near the border of New Hampshire. Most barns here are full 2" tenon 3 to 4 inches deep with a softwood 1" peg. I use 3/4" hardwood in most joints unless they are doing some major work.

Hi Tim,

I feel much better now. Though we debate sometimes I really respect your views and opinions. I always learn something because you challenge concepts really well and ask great follow up questions to the information others share.

I had a feeling when you said you are "pricking" to layout your draw boars that you are using scribe rule. As such that is the way it is (was) done. I would go as fare to say, historically, "pricking" is "the" method for draw boring, and the latter method of doing it all by measured off set is about the same age as "edge rule" (~300 years at the most.)

I also agree, since the onset of the industrial age, when "edge rule," came into its heyday, that folks in our craft of Timberwrights forgot the pleasures and benefits of "scribe rule."
I also agree, after more study and examination that I do not believe it is that much slower when all things are considered. In general application it may be, but the flexibility of design, broader range of material use and choice and uniqueness of frames using this method out way the draw backs.

I know this could be seen as subjective, but draw boring, and line rule are the roots of this craft and I like practicing them. Edge rule is nice, but I really wish our younger Wrights would star to embrace the soul of this craft and let the influences of the "industrial age" go.

If you ever find a frame with un-pegged braces in Maine please let me know, as that would be rare for that part (as is most) of New England. Norther and Eastern European influence is my current theory about un-pegged braces that are found in this country.

I drawbore all joints. Pegs may not be required after raising, but it is nice to pull everything together before raising an assembly.

Tim, I've been working on two Dutch barns for the last 3 1/2 years, both scribe rule. When I use square rule now, it feels a little odd. I want to use scribe as much as possible going forward. I think working with natural forms, like crucks and curved stuff will help justify using scribe rule. I've heard some people say that scribe is about 1/3 more time to cut a frame than square rule. I suppose it is if you don't test fit the square rule frame, which I don't, but I often hear of people test fitting square rule assemblies. Might as well scribe them, unless you don't have the room.

When I do edge square rule I bore peg holes with out fitting. On the scribe side I am enjoying not cutting all the reductions and housings. I only put such things in where loads should require more bearing surfaces, and then usually a haunch. I can get away with smaller dimensioned timber,too, that equals lighter sticks.

If I come across unpegged brace framiing I will let you know, Jay.

We have had this discussion before,
It is true that in theory oblique bracing works only in compression. Rudimentary design principles tell the logical mind that this should always be the case, so in other words examining a frame on paper will lead us to believe that a brace can act possibly in one direction only.

However, I have observed exceptions to this rule.

Case in point, my area in Indiana could be called the wind capital of the world. We get terrible winds during summer squalls frequently in excess of 60 mph with heavy rains carried on these winds -barn busters.

We also get these funny lookin clouds that are called tornadoes.

Both of these can cause frames to act in ways that are, well, unexpected.

Here, pegged braces can be the difference between success and failure during an instant-loading scenario during a severe storm. Central Indiana barn builders of the 19th century went to great lengths to built with this in mind. It is not unusual to see reinforcement in our barns that would be unnecessary in many other places.

I'd love to survey our barns in this region, if someone would pay me for it!

Now as for the OP, when it comes to drawboring a lot is left to personal preference. I can't really answer that any better than has already been stated by others, except to say that there is no concrete rule stating you HAVE to do it one way or the other, or you HAVE to draw all pegs, etc.

Hello David B,

For the sake of this discussion and what you just shared, I must also share once more that 90% or more of all bracing in traditional timber frames work only in compression, and any "tension" effect is from "binding." In the last 5 years we have collectively seen, taken apart, removed, and/or site surveyed hundreds of barns in Southern Illinois, Indiana and Ohio (among other places) a conservative 1/2 of all brace pegs are in failure of comprised due to lack of relish. The reason that pegging evolved in those regions was for exactly the reason that Tim, et al, have shared...ease and facilitation of raising. These pegs do little if any work in climate or seismic events. They do tend to keep the brace "in play," where others fall out, however, even with the pegging, many braces still dislodge due to complete peg and tenon failure.

Regards,

jay

Older barns with not so solid foundations can put loads on members in unpredictable ways. And then factor in a strong wind. I suspect there will be more than just brace peg relish failure.

Chuck in a long leaky roof to compile the problem.

You got it Tim...

These "poor creatures" have gotten the heck knocked out of them in the century or so of standing. We even had a nice Dutch Barn and threshing barns with some "relish failure," in the "anchor beam," and "swing or bull beams."

What you might find interesting from our other part of this conversation, is in the northern areas where you find they have not pegged the braces, you can often find the barns have had small shims or wedged pounded into the brace mortise to "tighten things up." You will on occasion find this with pegged braces as well, but no wear near as often. I agree it is a personal choice, but I do believe the wedge brace is superior, (perhaps subjective?) but it can perform all the same tasks as a pegged brace, it does not require boring a peg whole, can be serviced while within the frame, and re-tightened should there be some type of tectonic event.

I have also speculated and found reference in text, oral accounts, and research, that "pegged braces" are a vestigial style from the "let in brace" common in scribe rule. This system of brace (nod to David Bahler ) was common through out the mountain regions of Europe. It is one of the few bracing systems, when executed in certain design parameters will work in both tension and compression. Though the tension capabilities are limited, these frame types, when working in concert with all given components are some of the most resistant frames ever cut to tectonic and chronological distortion.

Correct, Jay. The barn I referenced indeed had blocks under the lower end of the brace. I don't recall if the top plates had blocks or not, the bottoms did for sure, maybe 3 inch blocks also not clear if they were wedge shaped. It was on an unofficial barn tour with some other forum members, a connecting girt frame.

Let's not leave out butt cut with spikes, as an option. There was a lot of that in my area in the early 1900s.

That is not one to forget for sure, and was more common at one time than folks think.

For cutting "contemporary" frames in a "traditional" fashion where a client wants braces, but has a limited budget (normal brace cost $75 to $150 per brace) there is the "let in trunnel brace." These are supper fast to cut, and can be installed after the frame is up. Not many surviving examples left, (maybe more hidden in house walls.) With this type of brace you "toenail" with one or two 25mm to 30mm peg (1" to 1.25".) The also make for a unique look as well.

Do you have a picture of the "let in trunnel brace"? I am not able to picture it

Hi Csievers1,

If you can get a copy of "Wood and Wood Joints, building traditions of Europe and Japan," by Klaus Zwerger you will see many examples and explanations. There are other text out there as well with good documentation of this technique.