Because trees were plentiful from the earliest settlement days,
the use of wood for all aspects of construction is not surprising.
Wooden shingles were lightweight, made with simple tools, and
easily installed. Wooden shingle roofs were prevalent in the Colonies,
while in Europe at the same time, thatch, slate and tile were
the prevalent roofing materials.
With the popularity of the revival of historic styles in the late 19th and early 20th centuries, a new technique was developed to imitate English thatch roofs. Photo: C.H. Roofing.
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Distinctive roofing patterns
exist in various regions of the country that were settled by the
English, Dutch, Germans, and Scandinavians. These patterns and
features include the size, shape and exposure length of shingles,
special treatments such as swept valleys, combed ridges, and decorative
butt end or long side-lapped beveled handsplit shingles. Such features
impart a special character to each building, and prior to any
restoration or rehabilitation project the physical and photographic
evidence should be carefully researched in order to document the
historic building as much as possible. Care should be taken not
to assume that aged or deteriorated shingles in photographs represent
the historic appearance.
Shingle Fabrication. Historically wooden shingles were usually
thin (3/8"3/4"), relatively narrow (3"8"),
of varying length (14"36"), and almost always smooth.
The traditional method for making wooden shingles in the 17th
and 18th centuries was to handsplit them from log sections known
as bolts. These bolts were quartered or split
into wedges. A mallet and froe (or ax) were used to split or rive
out thin planks of wood along the grain. If a tapered shingle
was desired, the bolt was flipped after each successive strike
with the froe and mallet. The wood species varied according to
available local woods, but only the heartwood, or inner section,
of the log was usually used. The softer sapwood generally was
not used because it deteriorated quickly. Because handsplit shingles
were somewhat irregular along the split surface, it was necessary
to dress or plane the shingles on a shavinghorse with a draw-knife
or draw-shave to make them fit evenly on the roof.
This reworking was necessary to provide a tight-fitting roof over
typically open shingle lath or sheathing boards. Dressing, or
smoothing of shingles, was almost universal, no matter what wood
was used or in what part of the country the building was located,
except in those cases where a temporary or very utilitarian roof
was needed.
Shingle fabrication was revolutionized in the early 19th century
by steam-powered saw mills. Shingle mills made possible
the production of uniform shingles in mass quantities. The sawn
shingle of uniform taper and smooth surface eliminated the need
to hand dress. The supply of wooden shingles was therefore no
longer limited by local factors. These changes coincided with
(and in turn increased) the popularity of architectural styles
such as Carpenter Gothic and Queen Anne that used shingles to
great effect.
Handsplit shingles continued to be used in many places well after
the introduction of machine sawn shingles. There were, of course,
other popular roofing materials, and some regions rich in slate
had fewer examples of wooden shingle roofs. Some western "boom"
towns used sheet metal because it was light and easily shipped.
Slate, terneplate, and clay tile were used on ornate buildings
and in cities that limited the use of flammable wooden shingles.
Wooden shingles, however, were never abandoned. Even in the 20th
century, architectural styles such as the Colonial Revival and
Tudor Revival, used wooden shingles.
Modern wooden shingles, both sawn and split, continue to be made,
but it is important to understand how these new products differ
from the historic ones and to know how they can be modified for
use on historic buildings. Modern commercially available shakes
are generally thicker than the historic handsplit counterpart
and are usually left "undressed" with a rough, corrugated
surface. The rough surface shake, furthermore, is often promoted
as suitable for historic preservation projects because of its
rustic appearance. It is an erroneous assumption that the more
irregular the shingle, the more authentic or "historic"
it will appear.