Summary
Substitute materials--those products used to imitate historic materials--should
be used only after all other options for repair and replacement in kind
have been ruled out. Because there are so many unknowns regarding the longterm
performance of substitute materials, their use should not be considered
without a thorough investigation into the proposed materials, the fabricator,
the installer, the availability of specifications, and the use of that
material in a similar situation in a similar environment.
Substitute materials are normally used when the historic materials or
craftsmanship are no longer available, if the original materials are of
a poor quality or are causing damage to adjacent materials, or if there
are specific code requirements that preclude the use of historic materials.
Use of these materials should be limited, since replacement of historic
materials on a large scale may jeopardize the integrity of a historic resource.
Every means of repairing deteriorating historic materials or replacing
them with identical materials should be examined before turning to substitute
materials.
The importance of matching the appearance and physical properties of
historic materials and, thus, of finding a successful longterm solution
cannot be overstated. The successful solutions illustrated in this Brief
were from historic preservation projects
involving professional teams of architects, engineers, fabricators, and
other specialists. Cost was not necessarily a factor, and all agreed that
whenever possible, the historic materials should be used. When substitute
materials were selected, the solutions were often expensive and were reached
only after careful consideration of all options, and with the assistance
of expert professionals.
Selected Reading
Berryman, Nancy D.; Susan M. Tindal, Terra-Cotta; Preservation of an
Historic Material. Chicago: Landmarks Preservation Council of Illinois,
1984.
Brookes, A.J., Cladding of Buildings. New York: Longman Inc., 1983.
Fisher, Thomas, "The Sincerest Form of Flattery," Progressive
Architecture (Nov. 1985).
Gayle Margot; David W. Look, AIA; John G. Waite, Metals in America's
Historic Buildings: Uses and Preservation Treatments. Washington, D.C.:
Preservation Assistance Division, National Park Service, U.S. Department
of the Interior, 1980.
Historic Building Facades. New York: New York Landmarks Conservancy,
1986.
Hornbostel, Caleb, Construction Materials: Types, Uses and Applications,
New York: John Wiley and Sons, Inc., 1978.
Lynch, Michael F; William J. Higgins, The Maintenance and Repair of
Architectural Sandstone, New York Landmarks Conservancy, 1982.
National Park Service, Rocky Mountain Regional Office, Preservation
Briefs 12: The Preservation of Historic Pigmented Structural Glass. Washington,
D.C.: Preservation Assistance Division, National Park Service, U.S. Department
of the Interior, 1984.
Phillips, Morgan and Judith Selwyn, Epoxies for Wood Repairs in Historic
Buildings. Washington, D.C.: Preservation Assistance Division, National
Park Service, U.S. Department of the Interior, 1978.
Phillips, Morgan W., The Morse-Libby Mansion: A Report on Restoration
Work. Washington, D.C.: Preservation Assistance Division, National Park
Service, U.S. Department of the Interior, 1977.
Tiller, deTeel Patterson, Preservation Briefs 7: The Preservation of
Historic Glazed Architectural Terra-Cotta. Washington, D.C.: Preservation
Assistance Division, National Park Service, U.S. Department of the Interior,
1979.
Acknowledgements
The author gratefully acknowledges the invaluable assistance of coworker
Michael Auer in editing this manuscript. The following individuals are
to be thanked for their technical assistance: Mary Oehrlein A.I.A., Washington,
D.C.; John G. Waite, Albany, NY: Hyman Myers, R.A., Philadelphia, PA, Thomas
Fisher, Stamford, CT; Harrison Goodall, Kinnelon, NJ. In addition, the
staff of Preservation Assistance Division, the cultural resources staff
of the National Park Service Regional Offices, and Stan Graves, on behalf
of the National Conference of State Historic Preservation Officers, provided
useful comments that were incorporated into the manuscript.
Washington,
D.C. September, 1988.
This publication has been prepared pursuant to the National
Historic Preservation Act of 1966, as amended, which directs the Secretary
of the Interior to develop and make available information concerning historic
properties. Technical Preservation Services (TPS), Heritage Preservation
Services Division, National Park Service prepares standards, guidelines,
and other educational materials on responsible historic preservation treatments
for a broad public.
"The Use of Substitute Materials on Historic Building Exteriors" an Historic Preservation Brief
