Decorative keystone
Decorative keystone refers to a wedge-shaped central accent element molded in high-density polyurethane designed to crown the apex of window surround architraves, arched portals, or door pediments. Replicating the classic structural masonry Voussoir stone that locks arch spans together, polyurethane keystones present an ultra-lightweight alternative that will not overload wall substrates or risk detachments. Weatherproof, frost-impervious, and UV-stable for interior or facade applications.
Frequently Asked Questions
Where is a decorative keystone applied?
It is positioned at the exact central apex of arch spans, exterior window headers, and door pediment assemblies.
What advantage does a polyurethane keystone offer over natural stone?
It is dramatically lighter than stone, bonds effortlessly with mastic adhesive, and never cracks under severe freeze-thaw weather.