The proper treatment and care for a roof isn’t only important for the preservation and protection of the resource. A roof is a major part of the overall character and interpretation of the structure and site. Despite proactive maintenance, the roof is a sacrificial layer for protecting the building and will ultimately require replacement.
Historic New England developed the following general guidelines for roof replacement:
Research and document the history and evolution of roofing on the resource as well as the failure mechanisms to understand the management requirements of the roof.
Monitor the condition of the roof and perform maintenance on the roof as required.
Generally, flashing and small roof leaks can be repaired without the replacement of the entire roof structure.
All roofing materials are sacrificial and will require replacement eventually.
Periodic cleaning and the routine application of appropriate preservatives may be necessary to prolong the lifespan of the roof.
Document the existing roof type and details before any work commences.
The first approach is to replace the roof in-kind, matching extant materials and details. The roofing system and appearance of the roof is part of the overall interpretation of the site and part of the historic accuracy.
Material replacements should match type and style as best as possible.
It is understood that roofing materials are a resource that requires cyclical renewal and preserving the previous generation of shingles in situ is not possible.