usually harder than brick or even stone masonry and will cause cracks in surrounding masonry units , or separate from the masonry , leaving gaps where water can penetrate . To maintain exterior masonry :
1 . Replace deteriorated or missing mortar with an appropriate mortar that includes lime in the mix . ( See the National Park Service Preservation Brief on mortar for guidance on mortar color and appropriate pointing techniques , available online at
https :// www . nps . gov / tps / how-to-preserve . htm . Click on Preservation Briefs and then select Brief 2 , “ Repointing Mortar Joints .”)
2 . Look for settlement cracks around windows and doors — open mortar joints in a step pattern , usually at the top or bottom or beginning at the corners . These open joints should be repointed and monitored . If cracks persist , retain the services of a qualified conservator or structural engineer to determine whether additional work is needed ( for example , the lintel at the top of the opening may require replacement ).
Wood Windows , Doors , and Siding
Wood windows and doors allow the nice weather in , and more importantly , keep the nasty weather out ! The easiest way to maintain these wooden building elements and features — and clapboard siding , cornices , and brackets — is to keep them painted . Unpainted wood will absorb water quickly , and wet wood will eventually rot . It is essential to replace missing and deteriorated window glazing putty , which keeps water ( and air ) from seeping around the window glass and , with small metal glazing points , helps to keep the glass in place .
1 . Look for signs of glazing putty deterioration such as cracking and water staining or peeling paint on the interior sides of the window muntins .
2 . Look for staining or peeling paint , especially at window and door sills , and along the bottom of doors where water may pool on a door threshold , and at downspout locations in cornices .
3 . Do not forget to look at masonry elements far above eye level , such as chimneys and towers . ( Binoculars are not just for bird watching !)
3 . Fill the gap between windows and doors and surrounding masonry with a flexible sealant to keep water out .
All building materials and systems have a natural life span and may need to be repaired or replaced simply because they have reached the end of their useful life . With diligent and proper maintenance , you can help minimize the need for and frequency of significant repairs .
ABOUT SUZANNA BARUCCO
Suzanna Barucco is the principal at sbk + partners , LLC , a historic preservation consulting firm providing professional services for the documentation , preservation , restoration , rehabilitation , and adaptive reuse of historic buildings , sites , and landscapes . She also teaches graduate courses in the historic preservation program at Jefferson University and serves on the Designation Committee of the Philadelphia Historical Commission .
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