HPCS U.S. Projects - Alexander Hamilton House

Where HPCS Non-Shrink Grout was born

Upper Manhattan, New York City (1804)


The Building:
National Historic Site, former residence of one of America’s founding fathers. 


The Problem:
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 GroutTM - 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 GroutTM  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.


GR Non-Shrink Grout 
GR Non-Shrink Grout™
TOOLS USED:            HPCS Micro-Jacks™