Hi Ken,
I would classify the Shirley Barn as a major varient of the CG tradition, as the plates are not continuous.
Remember also that angle ties, were used in circa 1300, as you correctly state, but that they also made a return, in the eighteenth and nineteenth centuries when "level assenbly" was adopted (The tie beam spanning the building is tenoned into the wallplate, and the top faces of both timbers are at the same level). Here the angle tie braced the roof plate frame, and in some circumstances had a dragon tie jointed into it to facilitate the jointing of the foot of the hip rafter. So the use of angle ties in nineteenth century US work had contemporary useage in Southern UK.

Hi Joe,

I was not aware of the existence of "level assembly" dragon ties in England and this just goes to show that building practices are probably not necessarily that widespread. Where can these buildings be seen in England ?

Re variant versus different typology my initial thoughts were as per your advice above but later I recognised that unless the plate is specifically positioned then it would not be able to accept common rafters whereas CG's can be variably positioned at different elevations but then of necessity a common purlin roof has to be employed. So is the Shirley barn a CG variant or simply an interrupted wall plate as per Jack Sobon's article in TF No 56.

Re the dragon ties employed at the corners of a building with fully hipped roof I agree that these are fitted primarly to facilitate the construction of the roof structure i.e. this component is really part of the roof whereas the primary function of the dragon ties employed between wall plate and tie beam on intermediate and gable frames are part of the (wall plate & tie) frame structure.

I well realise that some of this might appear to some as being symantics but in order to arrive at a classification acceptable to all then there would need to be some logical basis for decision making. Who is the arbiter on these matters ? I wish that Jack would occasionally chime in on the forum to offer his opinions.

I was probably wrong to say that Jack's article can be downloaded from the TFG website but it can certainly can be reviewed in TF 56 or providing I am not breaking any copyright rules I can send any one reviewing the content of this forum thread with a *pdf copy (0.8mb) of this article by email.

Regards

Ken Hume

What is the correct terminology. Connecting girts are just that, can we call these buildings CG buildings? Where Jacks writings point in the direction of Interrupted plates and dropped interrupted plates all within the classification of tie beams at the plate. Are there any historic buildings with both dropped ties and dropped connecting girts, other than the newer Benson type of rafter to post bent frames? Tim

Tim:

Sorry, I am not aware of Sobon's yellow covered book, only the biggie he wrote w/ Roger Schroeder.

But I'm proud to say that we have been accepted to tour the barn of the somewhat private owner (horray!)... the other barn (the more dillapidated one) is likely a shoe-in and I'll know on this one real soon. The somewhat private lady is a little concerned with the ammount of folks wanting to access the second floor and she wants to make some room/ clean up a bit... but she'll take 10 of us. Her 2nd floor is more sturdy that the other barn's that I said was like bouncy staging.

Housewright:

I guess we have the go-ahead for an event/visit, etc... do you think the two CG barns will be enough for the day, or should we try to schedule some other CGs. They're all within 20 minutes of each other...

I'll have to re-examine my photos, but since the discussions on the Shirley barn and what constitutes a true CG frame, one of the 5 CGs here may just be an interrupted plate frame and not dropped girts...

Don

Jim:

These are interesting. The Wilton frame w/ purlin roof is like what I have seen down here... the Deerfield one is odd in that it has common rafters (alongside the major ones). I've not seen this on any of the CG barns here.

The deerfield has a plate of some type supporting the common rafters. Is that continuous?

Don

Hi Ken,
I will defer any further from the classification debate. It is subjective, I can see both point of views, and being so far from the buildings!! etc.

Angle ties ( with no dragon ties) between level assembly buildings may be seen at

The saw pit shed, from Sheffield Park, nr Chailey, re-erected Weald and Downland Open Air Museum.Circa 1820

I have also worked on a Hay Barn from 1805 in Cuckfield with "normal assembly" that has angle ties between the tie beam and plate.
However a Hay Barn from Ockley, Surrey, also re-erected at the WDOAM from 1804/5 does not have angle ties with its level eaves.

These angle ties are lapped not morticed and tenoned.
So getting back on thread, then angle ties are found in early nineteenth century frames on both sides of the Atlantic.
The Sussex and Surrey ones are lapped with dovetails, whilst the NH examples appear mortice and tenoned.
Regards
Joe

Hi

Please forgive me for backing up so far in this thread. Much earlier, Ken asked about the TTRAG archives. As a member of TTRAG, I can tell you the archive does exist and has been given a home in Dave Lanoues beautiful shop in New York. The archive will not be available online until someone can spend the time to organize it and scan the information and create a site for it. I imagine all surveys are welcome to be submitted to the archive. Ask Dave at lanoueinc@aol.com for his mailing address.

Will, you made a comment about the circular saw being invented around 1816? The info I have is that the circular saw was invented in 1777 in Eengland, but took a long time to really come into use.

I cannot seem to navigate through the thread while writing this reply so I will need to submit it and then continue replying.

Jim

Ken, The Deerfield and Sherley barns are similar in that thay have tall posts which tenon into the rafters and have interupted tie beams. The Wilton barn has a single tie resting on top of four posts.

Will, I have heard that the distribution of common purlin roof systems is similar to the distribution of connected farm complexes. If you have the book Big House, Little House, Back House, Barn, look at page 20 (second edition). Connected buildings only occure in part of New England with the highest concentration in Maine.

Don, The Deerfield barn has a major purlin tenoned into the rafters. This major purlin carries the minor raftrers and is braced to the rafters.

Everyone, To add some information about the barns I posted images of; The Wilton barn is missing the lowest purlin in the images. It was a 2x8 spiked onto the ends of the ties. Also, the wall nailers were nailed onto the braces rather than being mortised into the posts.

Tim made a comment that there were "two barns" in Sherley. Technically it was just a two bay addition to the main barn but the addition was a complete frame unlike the two other barns which the two bay additions were attached to the last bent of the original barn without adding more posts.


I'll make a coment about the structural aspect of the barns with posts going all the way up to the rafters...Being interior posts which carry more floor load and roof load than the outside posts, you need to be sure the footings are sized properly to carry these posts. In the Deerfield barn these posts had settled several inches, and since the posts were pinned to the rafters,they pulled the rafters down in the middle creating a sag of perhaps four inches in the roof. Otherwise, it is a strong design.

Jack Sobon made a good comment in his joinery book about these "interupted plate" barns; once you get two bents up and braced, they are stable. Probably stable enough to help pull the remainder of the bents up with a block and tackle.

Don, good news about the barn tour shaping up. I'll call soon.

Jim

Hi Jim,

Thanks for that technical update.

I found myself going a bit squiffy eyed when watching the screen show as this moved a little too fast for my slow brain to follow and so please forgive any oversights.

I have contacted Dave and hopefully more news re the TTRAG archive will follow.

Regards

Ken Hume

Jim:

Interesting detail on the Deerfield barn, as far as the common rafters resting on a purlin. Like I said, all the CG barns I've seen here do not have common rafters at all. The date for this barn of 1851 or 57 is later than the 2 I've been posting pictures of... I wonder if this led the builders to the common (and sawn) rafter choice? Not even a birdsmouth/crowsfoot on them...

Anyway, it's unique... no two barns are the same, are they? That's what make it interesting, I think.

As far as the presense of purlin or common rafter methods throughout New England, Thomas Durant Visser's book "Field Guide to NE Barns and Farm Buildings," also gives a map on p.14...

All of New Hampshire is purlin teritory according to his map. But the map also says it depicts an 1840 time-frame... Neat barn. I've not seen that roof system before.

Don