Introduction
Plaster in a historic building is like a family album. The handwriting
of the artisans, the taste of the original occupants, and the evolving
styles of decoration are embodied in the fabric of the building. From modest
farmhouses to great buildings, regardless of the ethnic origins of the
occupants, plaster has traditionally been used to finish interior walls.
A versatile material, plaster could be applied over brick, stone, half-timber,
or frame construction. It provided a durable surface that was easy to clean
and that could be applied to flat or curved walls and ceilings.
Plaster could be treated in any number of ways: it could receive stenciling,
decorative painting, wallpaper, or whitewash. This variety and the adaptability
of the material to nearly any building size, shape, or configuration meant
that plaster was the wall surface chosen for nearly all buildings until
the 1930s or 40s.
Plaster was used as the interior surface coating of this elegant 1911 church located in Eugene, Oregon. Photo: NPS files. |
Historic plaster may first appear so fraught with problems that its
total removal seems the only alternative. But there are practical and historical
reasons for saving it. First, three-coat plaster is unmatched in strength
and durability. It resists fire and reduces sound transmission. Next, replacing
plaster is expensive. A building owner needs to think carefully about the
condition of the plaster that remains; plaster is often not as badly damaged
as it first appears.
Of more concern to preservationists, however, original
lime and gypsum plaster is part of the building's historic fabric--its smooth
troweled or textured surfaces and subtle contours evoke the presence of
America's earlier craftsmen. Plaster can also serve as a plain surface
for irreplaceable decorative finishes. For both reasons, plaster walls
and ceilings contribute to the historic character of the interior and should
be left in place and repaired if at all possible.
The approaches described in this Brief stress repairs using wet plaster,
and traditional materials and techniques that will best assist the preservation
of historic plaster walls and ceilings--and their appearance. Dry wall repairs
are not included here, but have been written about extensively in other
contexts. Finally, this Brief describes a replacement option when historic
plaster cannot be repaired. Thus, a veneer plaster system is discussed
rather than dry wall. Veneer systems include a coat or coats of wet plaster--although
thinly applied--which can, to a greater extent, simulate traditional hand-troweled
or textured finish coats. This system is generally better suited to historic preservation projects
than dry wall.
To repair plaster, a building owner must often enlist the help of a
plasterer. Plastering is a skilled craft, requiring years of training and
special tools. While minor repairs can be undertaken by building
owners, most repairs will require the assistance of a plasterer.
"Repairing Historic Flat Plaster" an Historic Preservation Brief
