Duhring Wing Exterior Restoration
that is listed on the Philadelphia Register of Historic Places. Constructed in 1916 as an addition to the main library of the University of Pennsylvania, the 22,000-square-foot building was converted to offices in the 1960s. Kelly Maiello led the project design team.
The scope of work included restoration of the masonry and terra cotta facade, window replacement, and upgrades to mechanical and electrical systems. The design team provided an energy model showing existing and designed conditions in order to review alternative and HVAC options. All restoration and replacement was designed to meet the requirements of the Philadelphia Historical Commission.
The design team conducted a thorough survey of the building’s exterior from swing and high reach and determined that the masonry would require repointing and cleaning. An analysis of the original mortar guided the team in selecting the mortar mix for the repointing.
The masonry cleaning required removal of atmospheric and biological staining, efflorescence and vegetation. To evaluate which cleaning method would be most effective in removing the stains without damaging the masonry, sample panels of brick and terra cotta panels were tested using:
Ultimately a light duty chemical cleaner and pressure washing water rinse was used on the majority of the masonry. In localized areas of stubborn staining this process was augmented by using a heavy duty cleaner and rinse. Vegetation growing in the masonry was treated with herbicide and all plant growth including the root system was removed.
The existing windows, original to the Duhring Wing, were single glazed, fixed steel, mulled window sashes with an operable awning type vent in the upper part of the window opening. On the fifth floor of the east and west elevations, the operable sashes have a decorative curved profile.