keystone arch

A keystone arch is a polyurethane decorative arch element with a keystone placed at its centre top. On window and door openings, on facades and in interiors, it is used to create a curved arch line and highlight the centre point. It joins with the side surrounds and arch profile to form a continuous frame. Polyurethane is lightweight and attaches directly to the surface with mounting adhesive; it resists moisture and impact, does not crack or blister, and is paintable. Being much lighter than its stone and plaster equivalents, it is easy to install even at high points. Being mould-cast, the arch profile and keystone detail are identical on every piece. Polure produces the keystone arch in different span and profile sizes.