Barn Preservation Society
to the Study and Preservation
of New World Dutch Barns
Spring 1990, Volume 3, Issue 1
Tree Nail in Timber Framing of the Past
By John Fitchen
Some years ago, I was on hand to observe what was
scheduled to be a Dutch Barn demolition operation. It seems that
the farmer had decided that the barn was too old and decrepit to
serve his needs, so he was taking steps to remove it in one quick
effort. A heavy steel cable was secured to the barn's frame, the
other end of the cable fastened to a heavy-duty caterpillar tractor
with the intention of collapsing the structure by pulling it down
in line with its axis. The tractor's engine was revved up and put
in gear, whereupon the cable became rigidly and dangerously straight.
But the barn didn't budge. Instead, the tractor reared up in line
with the cable. So the project had to be abandoned for the ignominious
alternative of having the barn's joints, one by one, laboriously
sawn apart. If ever there was confirmation of the fact that the
use of tree nails could result in a permanently secure, unremittingly
durable structure, this was it.
Instead of using metal nails or spikes to secure the joints in
timber framing, the carpenters of the past relied on the time-honored,
long established tradition of tree-nails: that is, all wood connections.
Trenails (or treenails) were hardwood pins or pegs whose use involved
profound consequences. For example, unlike metal nails, the trenails
had to be individually prepared and shaped, one by one, and the
holes for their insertion, in turn, had to be bored separately,
one by one. Moreover - and this was the most inexorable requirement
- joining the members had to be done by mortice and tenon (or some
analagous device) which meant that they could not be butted together.
Rather, a tenon had to be fashioned at the end of a member, for
insertion into a matching mortice.
The Greater Wemp Barn, formerly located at Schoharie
Crossing, NY, exhibits the ends of hickory pegs (trenails) which
secure braces to post and anchorbeam. Rare chamfering is exhibited
on braces. Also rare is the shaping of the anchorbeam where the
brace enters. The barn has been removed from its site, but will
be re-erected in Albany County, NY. Photo by Clarke Blair.
In consequence of this additional length in the member, the sequence
of assemblage was irrevocably determined. A horizontal strut, for
example, between two studs, could never be framed after both studs
were in place, and this absolute, categorical situation came about
because the length of the strut was greater than the distance between
the studs due to the presence of the tenons at either end of it.
These modifications - shaping the tenons and voiding the mortices
- obviously required skilled work, and considerable time, to execute.
But they also influenced the
order and sequence of the framing process in an inescapable way.
For whereas a nailed strut can be inserted at any time between
two stationary studs, the all-wood scheme of timber framing imposed
a sequence of operations at the start. Thus, with only one stud
in place, a tenon of the strut had to be inserted in that stud's
mortice before the other stud could be maneuvered into place so
as to engage the tenon at the strut's other end.
Consequently, compared to
the rapidity and off-hand ease of nailed attachment, pegged joints
required both time and precision in executing them. The holes
had to be laboriously bored by hand, using such tools as augurs
or wimbrels. And since the purpose of the pegs was that of achieving
a secure, permanent attachment of the two members, there had
to be some means by which the peg would not work out of the hole,
either due to shrinkage or to any movement due to vibration or
other stress in the joint. Where any such action was not expected
to be a problem, smoothly shaped pins were carefully hewn to
fit snugly into the hole. But wherever such action was anticipated,
a different procedure was adopted.
Obviously, the holes bored
to receive the pins (the trenails) were necessarily and inevitably
cylindrical, but the pins themselves were not. They were never
turned out on a lathe (as some wheel spokes and slender balusters
might have been, and modern dowels invariably are). Instead,
they were painstakingly shaped by hand, usually employing the
tool called a drawknife. The shaping operation that resulted
from the use of this tool quite naturally caused the pin to be
octagonal instead of circular in cross section. The longitudinal
edges - the arrises - made the pin oversized with respect to
the hole; consequently, it could not be slipped in and out but
had to be forced into the hole. This feature was intentional
and welcome, for the arrises bit into the sides of the hole,
preventing the pin from becoming loose and indeed resisting any
attempts to withdraw it subsequently. The joint, so fashioned,
was made permanently secure, thanks to the circle of longitudinal "teeth"
biting into the sides of the hole.
An extreme case of this gripping
function of the arrises of octagonally hewn tree-nails is to
be found in the thick planking of the floor of the Deertz Barn.
The jarring, pounding and bouncing effect of horse's hooves,
and of the heavily-laden hay wagons in season, had to
be positively guarded against at all costs. So here, astonishingly,
square pegs were driven into round holes. Obviously, this could
be done only by a heavy maul in the hands of a strong and particularly
adept worker. For, once driven home, or even perhaps split or
smashed in the process, there was no way in which the pin could
be drawn out; the hole would have had to be bored anew. The pegs,
bluntly tapered just enough at the entering end for them to be
firmly positioned upright in the hole, were square in section,
with sides the same dimension as the diameter of the hole. Since
both peg and flooring were of oak, it obviously took considerable
force to drive the pegs all the way in, but, once in, they were
there for the duration.
It should be recognized that, even where the craftsmanship was
of the highest quality, there were instances of the use of smoothly
cylindrical pins, or at least ones having long tapered points without
arrises. Such pegs were commonly used, temporarily, in the procedure
of test-assembling a timber framework before its final, permanent
consolidation. This requirement was an essential concomitant in
barn building, for example, where the columns had to conform to
both longitudinal and transverse linkages in the ensemble. Here,
in the double test-assemblage operations, the pins had to be quickly
and easily withdrawable, and hence without any gripping arrises.
In these two test assemblages-when first one and then the other
of the longitudinal and transverse test assemblages were involved
- the provisional pins were usually tapered, and they were invariably
made longer than the combined thickness of the two timbers they
penetrated. This extra length of the provisional pins meant that,
when driven into their holes, their smaller ends projected well
beyond the far side of the hole that accommodated them. This was
done in order that the pins might easily and quickly be removed
by tapping them out from their pointed ends.
Another and much less frequent instance in which smoothly contoured
pins were sometimes installed - permanently, this time - was in
situations where they were used to assure a very tight fit against
gapping at the joint, such as where the drawing apart or opening
up of the joint due to shrinkage had to be permanently and strongly
guarded against. Here, instead of boring the hole for the trenail
straight through both members of the connection at once (which
was the customary procedure), the hole, was bored through both
sides of the mortice, then separately and slightly off-set, through
the tenon. In this situation, when the two timbers were brought
together-when their mortice and tenon were linked - the hole through
them was unaligned. Hence, driving the tapered pin into and through
its hole caused it to exert great and continuous pressure in squeezing
the two timbers together at their joint.
The gripping function of the wooden pins' arrises is similar
to what happens in the case of metal nails which, in being driven
into the wood, force its fibers apart and thereby unite wood and
metal in a tenacious, permanent grip.
The degree to which precision was required in shaping the trenails
was augmented by a comparable handicrafted individualism existing
in the very tools of the carpenters in former times. Although the
bits of augur or wimbrel might be nominally of the same diameter,
these tools were not manufactured in a factory in innumerable replicas
but were forged individually. Consequently, in a sizeable undertaking
such as constructing a massive barn, the team of men assembled
to construct the project might include a number of carpenters,
each with his own kit of tools. The fact that their individual
augurs might vary even slightly in diameter meant that those assigned
to prepare the pegs had to be meticulously precise in shaping them-particularly
the smooth ones - in order that they might fit snugly into the
holes bored for them. No wonder that today" one occasionally
comes upon a smoothly contoured pin that is loose in its hole.
The foregoing comments go far to account for the universality
of the trenail as the essential unit in timber framing throughout
the past. It was essentially a handicrafted feature in which the
quality of performance was explicitly controlled at every step
of the procedure. When metal nailing eventually became universal,
the latter's rapidity of execution made the trenail and its not
inconsiderable advantages obsolete. But we can be deeply impressed
with the quality and integrity of the heritage of its surviving
John Fitchen, architect and formerly Professor
of Fine Arts at Colgate University, authored the book The New
World Dutch Barn: A Study of its Characteristics, Its Structural
System, and Its Probable Erectional Procedures (Syracuse
University Press, 1968).
If A Barn Could Talk
By Everett Rau
I am an Albany County Dutch barn. I was proud more
than two hundred years ago when the last pine shingle was put in
place on my roof and the last ironwood sapling was laid across
my anchor beams - to support a bumper crop of tall rye that had
been cradled and bound by the steady hands of the Ogsbury family.
The west sill of the Ogsbury barn awaits repair.Photo by
My wood shingles have long since decayed. Some kind owner put
some black tar paper on my roof to keep it from leaking; this also
aged and before many years needed repair. Seems farmers don't always
have ready cash, but finally, in the year 1929, Ev Rau's brother
Raymond, working for General Electric, had the money to put galvanized
steel roofing over that tarpaper on my roof.
In those years of the 1920's and 1930's, when Ev Rau was a boy,
laughing men filled me with loose hay in June and July. In November,
the traveling baler came, and then the cash crop was sold. But
farm prices over the years did not keep up with industry's wages;
no longer did I hear laughter in summer and fall and seldom did
any person come near. Yet I remember that in 1932 or 1933, men
jacked up my main posts, the supports for my big anchor beams.
They put some flat stones back under my sills, already half decayed.
But my owners forgot to keep watching for the frost action on my
foundation. Every year, my stone supports slipped away. Maybe Ev
Rau cared for me, but he was raising a family and working away
from home. He did not see the slow settling of one anchor beam
post (rotting was going on down below) or see my purl in plate
bend sharply, dropping down 10 or 11 inches. Nor did he notice
my sills were gone.
Years passed. Finally, Ev Rau retired and was back on the farm.
One day Mark Hesler asked him to join the Dutch Barn Preservation
Society. Ev had not thought about the historic value of his Dutch
barn until he took a Dutch barn tour and listened to visitors talking
about how once there were many old barns but how now they were
rapidly disappearing. Ev met Vince, Jack, Chris, Shirley and the
others. These people were concerned about saving Dutch barns. That
did it. The very next day, "Doctor"
Ev started looking at me to see what needed fixing.
Well, the good thing was that over the years I managed to keep
fairly dry because of my metal roof. But, even so, my purlin was
bent and cracked, my sills were gone, except for the section under
the granary, and I was eight inches out of level. My roof was sagging
due to my bent purlin plate. My doors were off or rotten on the
bottom. My flooring had been two inches thick, but it was rotten
four feet in from the doors. My floor supports were broken from
heavy tractor loads. My south siding was weathered by the sun until
it looked like a screen.
Soon Ev was digging under my anchor beam support posts with a
shovel and bar and a come-along. Some old stones were removed.
They were big, and they had been tipped sideways by settling. Ev
dug around them and poured concrete into the 40"deep hole
he had made. Two weeks passed. I thought I was forgotten again,
but one day I felt my bent purl in being gently raised by a hydraulic
jack. The plan was to jack up 2" that day and 2" the
next day, and so on until my purlin plate was straight.
My east sill once was 42'-3" long. Now it was rotted out.
To replace it, Ev cut one out that long, 9" by 10" thick,
with a chain saw. There is more to come. The west sill will be
sawed on our sawmill after Ev extends the carriage to support the
42' length. Now I have cement piers, four on each side. I'm not
level yet, but I look better. My door frame had an old notch on
top for a center pole for the two doors that used to swing there
in the opening. Maybe Ev will make a new set of wooden hinges like
I used to have. Maybe someday he will replace the hay barrack that
stood beside me. He knows that farmers still used them when I was
If I could speak, I would shout "Hurray!" for the people
in the Dutch Barn Preservation Society. But for them, I would have
to yield to the forces of nature - wind, rain, rot, ants, and,
Thanks to repair by Ev and the others, I can live on as a monument
to early settlers who braved the wilderness and endured many hardships
to start this farm. I knew those who fought to be free in the Revolutionary
War and others who went to the Civil War. Those families, and the
workers whose names are written on my timbers, "made it happen" for
you today. I hear you people are coming to measure and study me.
I'll be looking for you. Keep up the good work.
The author, Everett Rau, resides on his family
farm near Altamont, NY.
1990 Newsletter, Part Two
Dutch Barn Preservation Society
The Mabee Farm Historic Site
1080 Main St. (Rt. 5S)
Junction, NY 12150
Phone: (518) 887-5073
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