Chapter 4: Design

ACI Specifications
There are a number of qualities that every concrete skatepark should exhibit. The most important specifications are those that prevent the most common problems in skatepark construction: uneven finish work.

Kinks, bumps, washboard flat areas, or rough finish work can all result in a skatepark that is, at best, unattractive to skaters or, at worst, dangerous to ride. Most project specs involving concrete refer to standing specifications for particular aspects of the concrete elements instead of reiterating all of the basic instruction for how that concrete should be used. These “global” specifications are supplied by the American Concrete Institute (ACI) and are known to any construction company that specializes in concrete work. ACI specs contain instruction for different kinds of concrete structures and are referred to by section numbers.

There are many sections of ACI specs but some are of special interest to skatepark construction. The ACI section on concrete finishing, ACI 117, describes different degrees of concrete “roughness and flatness” that any concrete skatepark design specification should refer to. Without these specifications in the design, there is no instruction on how smooth or lumpy the skatepark surface should be.