We're a contractor building a hospital addition. We just found out that the new handicapped ramps have to be built to standards set in the Americans With Disabilities Act (ADA) that went into effect January 26, 1992. To help sight-impaired people, the act requires detectable warnings on walking surfaces of ramps. The detectable warnings must consist of raised truncated domes with a diameter of 0.9 inches and a height of 0.2 inches. The domes must be spaced at 2.35 inches and must contrast visually with adjoining surfaces. The material used to provide visual contrast must be an integral part of the walking surface. I understand that this surface also will be required on the ramped portions of sidewalk surfaces at intersections. My question: How do we produce this surface?
We just found that there's a patented concrete stamping mat available to produce the surface you described. A charcoal black release agent used with the mat also reportedly provides the required visual contrast. Concrete can be stamped with the mat when a 1/2-inch-deep depression made with the finger holds no water and the concrete maintains its shape in the depression. After the mats are placed, adequate pressure must be applied using body weight or stamping tools to ensure that the mat bottoms out and yields the desired detail on the surface. The mats can be purchased from Stampcrete, 17 Blackwood Dr., Liverpool, NY 13090, telephone 800-233-3298. We've also heard that Bomanite Corp. has developed a stamping tool. Bomanite provides tools only to licensed dealers. Its address is Bomanite Corp., P.O. Box 599, Madera, CA 93639, telephone 800-854-2094.