19th Century Brick, Paint and Plaster Investigation—Flag House and Star-Spangled Banner Museum
The Flag House and Star-Spangled Banner Museum is a complex of three buildings, the earliest of which was the home of Mary Young Pickersgill, who sewed the enormous flag inspiring the national anthem. The 1793 structure is a two story building with a shallow basement and an attic under a pitched roof. The exterior walls are load-bearing red brick masonry on a rubble wall foundation. The building has undergone numerous interventions and additions over subsequent years.
The building was exhibiting widespread failure of the interior paint and plaster finishes on the perimeter walls, up to a height of three feet above grade, suggesting significant rising damp. The paint was splitting and peeling, and the plaster beneath it was blooming with salt crystals (efflorescence). Wood baseboards in the hallway had rotted and already had been removed. Troubling piles of salt and disintegrated stone particles had accumulated along the rubble stone foundation.
We were contracted to assess the current conditions and determine the likely causes of the failures and possible solutions. We performed a thorough survey of the building and site. Several openings were made to gain insight into hidden structural conditions. Brick porosity and moisture content were measured in-situ, and samples of mortar, salts, and paint were removed for off-site testing. We developed a comprehensive treatment plan with recommendations for correcting drainage, installing means of waterproofing, and for dehumidification and salt removal within the house. Recommendations were tailored and prioritized based on the most immediate needs and budget of the client.