Upper Manhattan, New York City (1804)
National Historic Site and former residence of one of America’s founding fathers.
The flat plaster was failing in the principal rooms.
The Development of a New Product:
Historic Plaster Conservation Services worked closely with Naomi Kroll, Senior Conservator for the National Park Service, to develop a new product – HPCS GR Non-Shrink Grout™ – to fill and secure the space between the plaster and wood lath. The “non-shrinking” characteristic of this product is essential where the stress of shrinkage will produce alligator cracks in delicate plaster. Although GR Non-Shrink Grout™ is based on the original Morgan Phillips formula for re-attaching plaster, important improvements were made during this project, and both the HPCS formula and mixing cartridge are now patented.