A.Bill Palmer, former editor of Concrete Construction and the president of Complete Construction Consultants in Lyons, Colo., responds: There are several ways to build climbing walls. John McGowan, president of Eldorado Climbing Walls (303/447-0512, eldowalls.com) in Boulder, Colo., says glass fiber reinforced concrete (GFRC) panels are the best solution for realistic-looking rock walls.

His company casts GFRC panels in 6-foot-by-6-foot silicone molds made from imprints of actual rockfaces. During wall assembly, embedded steel plates within each panel are welded to a structural steel frame. The seams between the panels are reinforced with steel, then filled with GFRC sculpted to match the panels. Bolt holes fitted with tee nuts are placed in each panel to accommodate urethane handholds, which can be altered as needed to allow variations in climbing routes.

Climbing walls can also be made from OSB, then coated with a stonelike polymer concrete texture coat; or from molded fiberglass panels. These materials offer more climbing flexibility but look less like natural stone.

Finally, climbing walls can be constructed from shotcrete on steel lath, although they must be carved on the spot, a process that takes considerable experience and craftsmanship.

No matter what technique is used, it’s best to leave the design and construction of climbing walls to experienced companies. Safety and liability are obvious issues, but even details like the size of the landing zone at the foot of the wall and the placement of handholds require careful planning. Companies like Eldorado make predesigned walls that can be installed by a builder; to find them — or get more information about climbing walls in general — contact the Climbing Wall Association (720/838-8284, climbingwallindustry.org)