Showing posts with label traditional timber framing methods. Show all posts

Here's a couple of videos from a few years back of Gabel sawing with a couple of different guys. These videos were shot at the Carpenter's Fellowship meeting in 2006 at Avoncroft Museum. This particular set-up, which is similar to pit sawing, but is called see-sawing.

The Snap (sometimes called the French Snap) is an old framer's shortcut. The trick is to saw one of your tenon shoulders, roll the stick twice, and saw the end cut down to the same depth as the shoulder cut you just made. Then strike the waste firmly with a heavy mallet or the poll of your axe and it will split the grain along the cheek of the tenon. This saves you from sawing half of the end cut and splitting one tenon cheek. Oh, Snap!

A video of this weeks hewing...

This is extremely satisfying work, but also extremely taxing on the body. I think everyone is glad to have a few days to recoup before we tackle the next two, which we will hopefully get from the logger next week.

Josh and Rich cross-cutting the end cut of a hand-hewn 36-foot 8 x 10 yellow pine beam with Josh's Grandfather's saw.

Hand hewn is a term that is widely misused today to refer to almost anything with a rustic appearance. The real meaning is actually quite limited in application. Hand hewn refers to a timber that has been converted from a log using only axes -- most commonly a felling axe and a broad axe.

Most people who are "hewing" timbers today are using either a power planer to create a textured surface or are adzing sawn timbers -- both of these methods make an "interesting" texture, but are completely inappropriate for historic work, as the tool marks are completely different than what you see on authentically hewn timber. It is important to note that each hewer leaves behind subtle, tell-tale tool marks that allow an observant person to play detective and determine among other things whether the carpenter was left or right handed, which direction along the timber he was moving as he hewed, how high off the ground the log was, the size of the different axes used, whether one person hewed the entire timber or one man went up one side, while another man went down the other, whether two faces were hewed before the log was rolled, or whether one face was hewn and the log rolled each time.

I am sure that is much more information than most people care to know about how a carpenter swung his axe on a particular day a couple hundred years ago. Nevertheless, it is valuable information when it comes to understanding how a particular building was built; especially in terms of documenting existing timbers to better understand the original techniques or when we need to repair, restore, or replace damaged or missing timbers in a way that is consistent with the original means and methods. It is entirely possible when replacing a timber, to study other contemporary pieces from the same building and then hew the replacement the same way the original was done, reproducing the act of conversion as well as the product. Not only do I believe there is cultural value in this knowledge and skill--keeping alive and in some cases rediscovering the subtleties of a traditional building skill that mostly died--it is simply the most accurate process for reproducing a hewn timber. While I understand that such a level of detailed care is not appropriate for many jobs, occasionally it probably is – when accurately replicating parts of the original process is an important part of the clients program. Or when close just doesn't cut it – such as work done on cultural treasures.

Even on the more everyday projects, I still think it is important to recognize authenticity and to value it enough to avoid cheap imitation.

Last month I travelled to the UK to take part in a unique carpentry exercise. A dozen or so carpenters from the UK, Europe, and America came together with the goal of building a wooden structure strictly with 12th century tools and methods. Knowing what the rules were, we had left at home all of our framing squares, tape measures, spirit levels, power tools, pencils, and calculators, and brought instead our plumb bobs, dividers, chisels, and axes.

We met at a farm called Cressing Temple in Essex, England. In the 1200s this farm was owned and managed by the Knights Templar, who built two huge timber framed barns on the property. These barns, which are still standing, are called the Wheat Barn and the Barley Barn.

These barns are truly magnificent to behold. I felt small when I first walked into them. The locals refer to the Wheat Barn as "the finest 12th century timber building in Europe." That may be a bit of hometown pride talking, but it is hard to dispute that while you are standing in it. It is 70% original, and now houses a museum with interactive displays and a viewing platform--a gargantuan steel structure that resembles a MacDonald's playground. But it is nice to be able to get a closer look at the roof framing for those of us that do not travel with scaffolding.

The Barley Barn, built in 1220, was the inspiration for the structure we were to build. It has more repairs than the Wheat Barn, but is equally as impressive. The floor is open (no museums) and that makes it more striking and photogenic. Several years ago, a man named Adrian Gibson first noticed the geometric relationship between framing members. Adrian passed away in 2006, but his discovery has inspired Laurie Smith, a Welsh scholar, to continue to investigate the use of geometry in building design.

I was there to see for myself how (if?) a building could be built in three dimensions using only geometry to locate framing members. It also seemed like a good chance to clear my head and get back to basics--plumb, level, and square. The mysterious Daisy Wheel, sort of a medieval protractor, seemed like it could be added to that short list, but I had to see it work firsthand.

In next weeks installment, we get into some serious hewing, and blood is spilled.