Identify, Retain and Preserve
Identifying, retaining, and preserving roofs--and
their functional and decorative features--that are important
in defining the overall historic character of the building.
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 its
size, color, and patterning.
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The steepness of this standing seam metal roof, along with its multiple dormers and double chimneys, characterizes this historic building. In Preservation, materials and features are carefully retained during a work project.
Photo: NPS files.
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Altering the roof and roofing materials which are important
in defining the overall historic character of the building
so that, as a result, the character is diminished.
Replacing historic roofing material instead of repairing
or replacing only the deteriorated material.
Changing the type or color of roofing materials.
Stabilize
Stabilizing deteriorated or damaged roofs as a preliminary
measure, when necessary, prior to undertaking appropriate
preservation work.
Failing to stabilize a deteriorated or damaged roof
until additional work is undertaken, thus allowing further
damage to occur to the historic building.
Protect and Maintain
Protecting and maintaining a 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.
Protecting a leaking roof with plywood and building
paper until it can be properly repaired.
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Pressed metal shingles, whose surfaces created interesting patterns, were popular throughout the
country in the late 19th century. Tin roofs were kept well-painted, usually red; or, as shown here, in a color that imitates the green patina of copper. Photo: NPS files.
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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
structure.
Allowing roof fasteners, such as nails and clips to
corrode so that roofing material is subject to accelerated
deterioration.
Permitting a leaking roof to remain unprotected so
that accelerated deterioration of historic building
materials--masonry, wood, plaster, paint and structural
members--occurs.
Repair
Repairing a roof by reinforcing the historic materials
which comprise roof features using recognized preservation
methods. The new work should be unobtrusively dated
to guide future research and treatment.
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It is particularly important to preserve materials
that contribute to a building's historic character,
such as this highly visible slate roof. In the
event that repair and limited replacement are
necessary, all new slate would need to match the
old exactly. Photo: Jeffrey S. Levine.
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Removing materials that could be repaired, using improper
repair techniques, or failing to document the new work.
Failing to reuse intact slate or tile when only the
roofing substrate needs replacement.
The following work
is highlighted to indicate that it represents
the greatest degree of intervention generally
recommended within the treatment Preservation,
and should only be considered after protection,
stabilization, and repair concerns have been addressed.
Limited Replacement in Kind
Replacing in kind extensively deteriorated
or missing parts of roof features or roof coverings
when there are surviving prototypes such as cupola
louvers, dentils, dormer roofing; or slates, tiles,
or wood shingles on a main roof. The new work
should match the old in material, design, color,
and texture; and be unobtrusively dated to guide
future research and treatment.
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Repairs on this pantile roof were made
with new tiles held in place with metal
hangers. Photo: NPS files.
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Replacing an entire roof feature such as a cupola
or dormer when limited replacement of deteriorated
and missing parts is appropriate.
Using material for the replacement material that
does not match the historic roof feature; or failing
to properly document the new work.
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