Barn Preservation Society
to the Study and Preservation
of New World Dutch Barns
Spring 1990, Volume 3, Issue 1, part two.
owner contemplating repair or maintenance of any barn needs
to know as much as possible about the history of the barn in
question. The barn's original use, the additions and changes
that have been made, and the way the setting has been altered
over the years are basic pieces of the puzzle. Before beginning
work, the owner should try to unravel the construction secrets
of the barn. Last comes assembling information about possible
preservation/repair choices as well as about methods for each
proposed repair. The following article and Everett Rau's "If
a Barn Could Talk" deal with this process.
Suggested Guidelines for
Timber Frame Repairs
Text by Dave Carlon
Illustrations by Jack A. Sobon
Over time, barns are subjected
to weather, traffic, accident and hard use, and therefore, require
periodic maintenance and repair. Where maintenance is neglected,
structural repairs to the timber frame itself may become necessary.
Whether a barn needs only minor repair or shows signs of serious
deterioration, non-barn related debris and stored extraneous materials
should be cleaned out on the interior, and moisture-producing trees,
shrubs and weeds should be cleared away on the outside. Then, an
initial survey identifying two categories of information needs
to be compiled. One category should list the frame component or
part thereof needing repair (sill end, post bottom, rafter foot,
etc.); the other category should name the cause of the problem
necessitating the repairs to each part. From this information,
a two-phased plan is made to 1) rectify the causes for the problem,
and 2) make the actual repairs. Rectifying the cause of the problem
may be enough to prevent further deterioration and actual repairs
may not be necessary. For example, a leaking roof will cause water
staining, which with frequent enough wettings can lead to fungal
growth and rot. This sets up favorable conditions for insect damage,
and eventual structural failure will be a result. Repairs to the
roof at the initial stages of this scenario will preclude the later
stages. Unfortunately, often detection occurs at a much later stage
and more substantial repairs are required.
There is a story to be told by each component member of a barn
- the variety of tree species used in a barn, its place in the
frame (i.e. white oak sills for rot resistance), its form (white
pine can be straight enough for 60-foot single piece plates), its
grain character and wood properties. Each choice made by the builder
bespeaks the forest of the period or the wood supply available
at the time the barn was built, as well as revealing something
about local technology at the time. Each hewn surface has recorded
on it the footprint of the tools used and the method used to fashion
that component. One part may contain inscribed markings and numberings
of consequence to the whole building, which is indeed greater than
the sum of its parts. There are also stories in the frame which
we have not yet learned to read. In as much as these buildings
are a link with our past and with endangered traditions, repairs
should be planned and carried out with the underlying philosophy
of preserving as much of the original fabric of the structure as
The repair process involves deciding on a temporary or permanent
repair, designing the repair, choosing the compatible or appropriate
repair material(s), and carrying out the repair. While temporary
repairs are generally quick and may reflect an emergency situation,
permanent repairs are more thoroughly designed for an effective
and eye-pleasing solution, conforming to the original parts in
form and function. Choosing a wood with natural decay resistance
may be desirable. USDA's Wood Handbook: Wood as an Engineering
Material, 1974, lists among others the following species as
resistant or very resistant to heartwood decay: black cherry, black
locust, white oak, chestnut, and black walnut. More important is
that the repair wood be as strong or stronger than the original
in load-bearing parameters. Current design values such as those
published by the Northeastern Lumber Manufacturing Association
should be consulted. Repair illustrations follow.
Temporary repair for decayed or broken rafters,
beams, and joists.
The authors are timber-frame specialists with
a particular interest in barns.
Dutch Barn Basics - Cues
to Understanding Your Barn
The following information on foundations, roofs
and siding of barns is extracted from "Dutch Barn Miscellany," an
informal publication authored by Dutch Barn Preservation Society
Trustee and founding member Vincent Schaefer.
The foundation of the Dutch Barn characteristically consisted
of piles of flat or semi flat stones arranged to support the sills
of the barn; the stones were located at strategic spots around
the periphery and under the posts supporting the anchor beams.
Thus, the floor of the barn was held several feet above the ground
so as to permit adequate air circulation beneath the barn floor.
In some instances, if the barn must be located on a moderate slope,
a solid dry wall was built so that the sills were level. This never
interfered with good ventilation. The sills were large, frequently
12" by 12" in cross section. With larger barns, there
was a center or median sill (see illustration) which permitted
utilization of floor planks slightly less than half the width of
the threshing floor. The stone piers used to support the sills
were generally of native sandstone or limestone which splits naturally
into convenient thicknesses. When the ground beneath the barns
was dry, problems with frost heaving were of no consequence.
The floors of many Dutch barns are original. They may consist
of oak planks 3 to 4 inches thick, 12 to 15 inches wide, and 12
to 16 or more feet long. These rest on top of the sills and in
some instances are fitted into a median strip. (See the Dutch Barn
Preservation Newsletter, Spring, 1989.) In some cases, the heavy
plank floor is made of unevenly split planking-with some of the
planks as much as six inches thick. These are recessed on the sills,
so as to be even with adjacent, thinner planks. Frequently the
planks are fastened to the sills with wooden pins (trunnels or
tree nails) similar to those used to secure other framing members.
Roof coverings may range from original plank roofs or shingles
to modern coverings. In a few instances, slate roofs (not original)
have been installed. Metal sheeting has been used on many barns.
When properly installed, such a roof is probably less expensive
than any other and has a long lifetime.
The sheathing of the side walls of the Dutch barns of the Hudson,
Mohawk and Schoharie valleys consisted of pine planks. The planks
of classic barns are generally 1" thick and 13" deep,
and may be some 13 to 15 feet in length. They were horizontally
applied and lapped by an inch or more and were nailed directly
to the posts (above, not through, the board below) with large hand-wrought
rosehead spikes. (See illustration.) In most instances the boards
were not painted but were allowed to "weather."
In the siding on the upper part of the gable ends were three to
five martin holes which served a dual purpose; they ventilated
the upper part of the barn as well as providing ready access to
the barn's interior for martins, other swallows, and any other
birds who chose to enter and feed on the insects brought into the
barn with the harvest. A number of barns are still sheathed with
original planking cut more than two centuries ago. Without paint
protection, this asserts the durability of virgin pine lumber so
long as it is kept dry. When wet by driving rain, the wood would
quickly dry once the storm had passed.
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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