Identify, Retain and Preserve
Identifying, retaining, and preserving roofs and
roof features from the restoration period. This includes
the roof's shape, such as hipped, gambrel, and mansard;
decorative features such as cupolas, cresting, chimneys,
and weathervanes; and roofing material such as slate,
wood, clay tile, and metal, as well as size, color,
Clay tiles are one of the most distinctive and
roofing materials because of their great variety
of shapes, colors, profiles, patterns, and textures.
Tapered barrel clay roof tiles were custom made for
the restoration of the 1820s Indian barracks at
Mission Santa Cruz. Photo: NPS files.
Altering roofs and roof features from the restoration
Failing to properly document roof features from the
restoration period which may result in their loss.
Changing the type or color of roofing materials unless
the work can be substantiated by historical documentation.
Protect and Maintain
Protecting and maintaining a restoration period roof
by cleaning the gutters and downspouts and replacing
deteriorated flashing. Roof sheathing should also be
checked for proper venting to prevent moisture condensation
and water penetration; and to insure that materials
are free from insect infestation.
Providing adequate anchorage for roofing material
to guard against wind damage and moisture penetration.
After a hurricane or other natural disaster,
it may be necessary to stabilize a roof temporarily
until materials can be obtained and a qualified
roofing contractor hired. Significant slate roofs
should not be stripped off and replaced with asphalt
shingles. Photo: NPS files.
Protecting a leaking roof with plywood and building
paper until it can be properly repaired.
Evaluating the existing condition of materials to
determine whether more than protection and maintenance
are required, that is, if repairs to roofs and roof
features will be necessary.
Failing to clean and maintain gutters and downspouts
properly so that water and debris collect and cause
damage to roof fasteners, sheathing, and the underlying
Allowing roof fasteners, such as nails and clips to
corrode so that roofing material is subject to accelerated
Permitting a leaking roof to remain unprotected so
that accelerated deterioration of historic building
materials--masonry, wood, plaster, paint and structural
Failing to undertake adequate measures to assure the
protection of roofs and roof features from the restoration
Repairing a roof from the restoration period by reinforcing
the materials which comprise roof features. Repairs
will also generally include the limited replacement
in kind--or with compatible substitute material--of
those extensively deteriorated or missing parts of features
when there are surviving prototypes such as cupola louvers,
dentils, dormer roofing; or slates, tiles, or wood shingles.
The new work should be unobtrusively dated to guide
future research and treatment.
Within a roof restoration project, a severly
deteriorated slate has been removed; the new slate
is being secured with a nail. Photo: Jeffrey S.
Replacing an entire roof feature from the restoration
period such as a cupola or dormer when the repair of
materials and limited replacement of deteriorated or
missing parts are appropriate.
Failing to reuse intact slate or tile when only the
roofing substrate needs replacement.
Using a substitute material for the replacement part
that does not convey the visual appearance of the surviving
parts of the roof or that is physically or chemically
Commercially available modern shingles and shakes
are for the most part machine-made. Roofing products
with rustic split faces are not appropriate for
historic preservation projects. Photo: NPS files.
Replacing in kind an entire roof feature from the
restoration period that is too deteriorated to repair--if
the overall form and detailing are still evident--using
the physical evidence as a model to reproduce the feature.
Examples can include a large section of roofing, or
a dormer or chimney. If using the same kind of material
is not technically or economically feasible, then a
compatible substitute material may be considered. The
new work should be unobtrusively dated to guide future
research and treatment.
(left) These weathered historic 19th-century
handsplit and dressed shingles were found in place
under a later, altered, roof. (right) In the restoration,
these replacement shingles matched the historic
shingles and were of such high quality that little
hand dressing was needed at the site. Photos: John Ingle..
Removing a roof feature from the restoration period
that is unrepairable, and not replacing it; or failing
to document the new work.
The following Restoration
work involves the removal or alteration of existing
historic roofs and roof features that would be
retained in Preservation and Rehabilitation treatments;
and the replacement of missing roof features from
the restoration period using all new materials
in order to create an accurate historic appearance.
Removing Existing Features from Other Historic
Removing or altering roofs or roof features
from other historic periods such as a later dormer
or asphalt roofing.
Documenting materials and features dating
from other periods prior to their alteration or
removal. If possible, selected examples of these
features or materials should be stored to facilitate
Failing to remove a roof feature from another
period, thus confusing the depiction and of the
Failing to document roofing materials and roof
features from other historic periods that are
removed from the building so that a valuable portion
of the historic record is lost.
Re-creating Missing Features
from the Restoration Period
Re-creating missing roofing material or a roof
feature that existed during the restoration period
based on physical or documentary evidence; for
example, duplicating a dormer or cupola.
Restoration of the Camron-Stanford House,
Oakland, California, focused on the replacement
of missing roof cresting and chimneys from
the restoration period, based on careful
documentation. Photo: Before, NPS files;
After, Courtesy, James B. Spaulding.
Constructing a roof feature that was part of the
original design for the building, but was never
actually built; or constructing a feature which
was thought to have existed during the restoration
period, but for which there is insufficient documentation.