Will, Sussexoak, Ken:

Yes, what is a dap?

I too have read the terns "Major" and "Minor" in regard to purlins. I interpret it as follows: Minor is another word for common purlin (smaller roof memnbers). Major is found in a common rafter system when the span is so great that a single beefy (major) purlin runs the length of the building, halfway between eve and ridge and supports the common rafters perpendicularly in the center of their span.

As far as obviously pegged purlins in the CG frames I've seen, there is a single peg through the rafter where the purlins intersect... looks like one peg holing both purlins (lapped?)...unless they're really long purlins and span 2 or more bents!

You can look at this photo of the actual barn I'm refering to here:
http://i286.photobucket.com/albums/ll84/mainebarns/GrayCornerskyward.jpg
But, you'll have to zoom in to see the pegged areas.

These rafters are spaced like the others, about 3-4 feet O.C.
This barn is an old hand hewn frame from the early 1800s. 1820 the owners say.

Will, it would seem this CG system spans a significant time period of at least 6 decades. The latest CG frame I encountered is sawn stock (circular) and dates to 1880. Again, the owners say.

I'm planning to revisit these soon and take many close up pictures, especially of the roof details... what else should I photograph... one thing that comes to mind is sills/bottom plates, and what they did on this part of the wall.

the dovetailed purlin comment was just for the sake of conversation. I have not seen this. Someone (sussexoak?) was asking about tying things together so the purlins dont fall out. I thought a dovetail would be a good solution. Albeit a lot of work!!

I'm excited about what's happened w/ this thread. I knew when I saw this style of construction it was unusual. You guys have been a great help.

may the education continue

Don

Ken --

A Dap is a term used commonly here in NE (and increasingly elsewhere) meaning the use of a simple notch - a housing like joint, (though always deeper) which serves in some non housing application.

Joe --

Did we cross paths in '02 whaen I demonstrated at Frame at the Weald & Downland, and was hanging about nextdoor with Ken at West Dean College ?

Don --

Yes, Connecting Girt Framing in many iterations was used through to the end of historical timber framing in the area.

I only made mention of the dovetail/CP issue in that it is a common misconception in the community that this is a historical detail.

Looking forward to your pictures.

Hi Will,
Yes we met when you kindly came over to the Museum as part of Frame 02 and demonstrated with Rudy Christian a couple of versions of Square Rule.
In this thread that I am following from a distance it is intriguing to see how assumptions based on my local experience in Sussex, are not applicable in different circumstances. In the latest instance there is no need to cut the purlins to bay lengths, when long 2 bay length timbers are easily available and you can simply house them into the top of the principal rafters.
The "new" name for butt purlins is tenoned purlins. They are found either in line or staggered from bay to bay, and the common rafters are either morticed into the purlins or pass over the top of the purlin. So 4 major variations available, with 2 typically found.These are tenoned purlins, in line, with rafters passing over the top and tenoned purlins, staggered, with tenoned rafters.
Anyway all fascinating stuff to hear about CG framing.

Hello everyone;

I never thought much of connecting girt (CG) framing because they are common in my experience in New Hampshire and now Maine. I live almost half way up the coast of Maine, and there are quite a variety of framing styles here including both common rafters and common purlins and more.

Will, I have been looking at historic lumber terminology lately and have realized how language vaires by location and time just like framing styles. I have never heard the terms dap or butt purlin before.

I have formed the opinion that frame science, like natural science, will eventually need scientific (Latin?) terminology for clear, global communications.

I would be interested to know the details of the earliest known CG frame.

Jim

Jim, I think I mentioned this in a past post, I don't see any CG frames in my area reinforcing your framing/language therory. I am only up the coast a short way from you. Tim

Folks:

I revisited both these barns last week and have posted small slideshows on PhotoBucket.

There is much, much to share about these two "connected girt" buildings. We're lucky in that both barns represent different classes of folks (farmers/gentlemen). And both are in the same town within 3 miles of each other here in southern Maine. Both are from the early 1800s.

"Barn 1" goes with a prominent brick house in the center of town and was/is sided w/ clapboards. It was not a common farmer's building.

"Barn 2" sits alone and was a common farmer's building. The house is gone. Clapboards were added sometime later in the barn's history. I know this because there are still interior battens covering the joints between the vertical boarding. The battens made it weather tight originally. (Interior battens are something I was unaware of until recently. They are quite thin...1/4 to 3/8" and are wider that you'd think...3"). I also pulled 2 nails from the vertical boarding on this barn (see slideshow). They're cut, not forged, and measure a uniform 3-5/8" long.

Roof details:

Barn 1 is 40 X 54 and has a bent spacing of about 13 feet. The major rafters are very slightly tapered towards the peak and measure about 7 X 9 at the butt. Purlins are roughly 4' O.C. and sit in a notch (dap?) cut in to the rafter. The purlins are flush with the top of the rafters. They're also pegged straight through. The run of the purlins is half the building's length, meaning they span more than one bay. They're staggered and run slightly past each other where they meet at the rafter.

Barn 2 is 40 X 50 with a bent spacing of about 10', and is overall more stoutly built. But time has not been as kind. It is far more deteriorated. Look at the exposed exterior framing at the eave on the slideshow of this barn (Barn 2). With the absence of a top wall plate, you can see what they came up with to attach the roof boards at the eaves.

the rafters are 8 X 8 and do not appear to be tapered. The purlins are notched into the major rafters like Barn 1. Some span more than one bay, some do not. Again, they're spaced about 4' O.C.

Walls:

Whats interesting is a couple of variations...

Barn 1 has the topmost connecting girt fairly close to the top of the post, about 6". And the wall boards are not uniform lengths at the top of the walls (random).

Barn 2 has the topmost girt about 12" down from the top of the post and the wall boards are nice and uniform to the roof eave.

My thinking is that the sloppy wall board length has something to do with whether the barns' exteriors are trimmed or not. Barn 1 has its soffit trimmed out, Barn 2 does not.

I'll try and answer what I can. It's been pretty interesting.

Housewright is correct: The closer you look, the more you see...

Here are the photobucket links:

Barn 1 :
http://s286.photobucket.com/albums/ll84/mainebarns/?action=view&current=2af69292.pbr

Barn 2:
http://s286.photobucket.com/albums/ll84/mainebarns/?action=view&current=9a35a90e.pbr

Don

The mystery seemingly deepens...

Don - As I've suggested above, I've never been in a Scribed Connecting Girt barn, and I've restored or repaired more than a few, and have been in countless more. (every opportunity to explore any historic frame that comes up - Often work diven "Would you look at my barn ? kinda things - but also any Antique Store, Farm Stand, Barn Sale, or neighbor in his barnyard opportunity that arises) And here you find a pocket of them, both the CG Barns in your photographs are Scribed.

It might be that the cross section I have visited is not large enough to accurately reflect developed patterns, or it might be that there were some hard headed locals who were happy to build to their clientels desire, in the new framing style, but chose to continue to lay out their framing in the method they preferred and were comfortable in - One of the most mysterious aspects of the rapid shift to Square Rule is why it overcame the (human) natural tendency of people to resist change and stick with what they know best - Paradoxically, it is in some ways easier to scribe a CG barn than its plated counterpart, it is simply earier to move small pieces around than it is to move long continuous or scarfed plates. In the end the choice of Square over Scribe is only the trading of one set of tasks for a different set of tasks - The carpenters who witnessed and participated in the shift would have known both sets - Both have their advantages, and to my mind, SR is not a clearly superior choice - Which leaves only personal preference or fashion or following the trend of the competition - Making it only that much more mysterious.

Have you researched or verified the dates of construction of these barns ? I'd like to see them if you're willing and it can be arranged, I'm guessing I'm only about an hour or so from you, Lebanon being the closest border town.

Jim - Butt Purlin is an English term, and one Sussex Oak suggests has been superseded. Dap is a term common to bridgewrighting, where such joinery is common, bypassing webs often being let into one another (double dapped) or chord lams being let into posts. It does seem to be coming into more common usage in the trade, I was recently brought to a smile, while in a joinery planning session in recently co-instructing this years FTX, one of the other instructors used the term.

Besides, Dap, despite, or perhaps because of, its seeming simplicity, extends a certain elegance and eloquence, simply not found in notch.

http://dictionary.reference.com/browse/dap

And I would have attended your historic framing get together, had I not been out of the area.

I too, would be interested to know the details of the earliest known CG frame, and as a fellow philologer / student of the ever evolving derivation of words and terms, and especially those common to our trade, I'd be interested in knowing the contemperaneous term for this framing methodology - Did ironwork borrow the term from timberframing or did the timber framing revival borrow it from ironwork ?

The look and description of "dap" would be what I would call a lap. Another name could be housing.
So is dap a corruption of lap?
Laps, mortice and tenon, and scarf joints being the 3 major jointing families used in English timber framing.

The recent use of dap to me is new. A dap to my thinking is the slight recess for a piece of steel, for instance a circular countersink for a shear connector to drop into or for a Simpson type strap to fit flush in.

Not saying I know what I'm talking about though.

I can see how dap would be applicable. The surface of the water is just broken, and the surface of the rafter is just broken, a dap.

On a road trip today I stopped at 3 barns, the first 2 no one home and the third someone was there and happy to have the barn looked at. It was a mutt, mixed with older/used timber, mortices in crazy spots, scarf joints, and English top plates used as principal purlins put in up side down exposing the dovetails to below. These were matching plates about 40' long with scarfs extending to about 60'. It had a queen rod truss as the second bent, I'm guessing to allow the animal to swing around as they came in the gable end door. Still no CG's.

Tim