The application or installation of synthetic siding can severely compromise the appearance and integrity of historic buildings, often obscuring and damaging original or later historic details and materials. While application of synthetic siding may cover a problem, it will not rectify it and may even accelerate existing causes of damage. For example, paint failure and clapboard damage are often caused by faulty gutters and downspouts. If this drainage system is not repaired before installation, runoff water may get trapped behind the siding, causing even more damage. In addition, synthetic siding may create its own moisture problems.
Wood clapboards breath by allowing moisture created by differences in temperature between the inside and outside of
the house to migrate to the exterior before condensation occurs in the walls. Unless an interior vapor barrier is
installed, the impenetrable layer created by aluminum or vinyl siding will trap excess water vapor which
condenses and not only damages wood but can also contribute to the formation and growth of mold.
Retain original or historic siding material if possible. If residing is required, repair or replace with new
materials that duplicate or match the original or later historic materials as closely as possible. The
appropriate historic siding materials are clapboard, brick, and on certain historical building styles, wood
shingles. Siding materials such as aluminum, vinyl, asphalt, mineral or synthetic that were unavailable
when a building was originally constructed are not appropriate and their installation will not be
Exception: Composite siding materials might be considered on a case by case basis.
Determining factors might include but not be limited to durability, application, and visibility of the
material from a public way. Samples of composite siding materials should be reviewed
by the Historical Commission to find a visually acceptable substitute.
The Historical Commission strongly recommends the use of white or red cedar for replacement exterior siding and
trim due to its decay resistance and long lasting properties. Back priming all exterior wood materials
prior to installation is also encouraged.
Removal of vinyl and aluminum siding is encouraged.