<photo>Detail of preserved exterior wood; Link to National Park Service
STANDARDS FOR PRESERVATION AND GUIDELINES FOR PRESERVING HISTORIC BUILDINGS
<photo> detail of historic tile roofing

Identify    Stabilize    Protect    Repair    Replace in Kind  

Identify, Retain and Preserve

Recommend
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.

photo of standing seam roof with multiple dormers and double chimneys

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.

Not Recommended
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

Recommend
Stabilizing deteriorated or damaged roofs as a preliminary measure, when necessary, prior to undertaking appropriate preservation work.

Not Recommended
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

Recommend
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.

photo of a tin roof painted to imitate the green patina of copper

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.

Not Recommended
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

Recommend
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.

photo of character-defining slate roofing

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.

Not Recommended
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

Recommend
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.

photo of pantile roof repairs

Repairs on this pantile roof were made with new tiles held in place with metal hangers. Photo: NPS files.

Not Recommended
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.

 

 

-GUIDELINES-

The Approach

Exterior Materials
Masonry
Wood
Architectural Metals

Exterior Features
Roofs
Windows
Entrances + Porches
Storefronts

Interior Features
Structural System Spaces/Features/Finishes
Mechanical Systems

Site

Setting

Special Requirements
Energy Efficiency
Accessibility
Health + Safety

The Standards

 

  HISTORICAL OVERVIEW - preserving - REHABILITATING - RESTORING - RECONSTRUCTING

 main - credits - email

Historical Overview