Guards and handrails are like peanut butter and jelly: They can be in the same sandwich, but they’re distinct ingredients. While guards and handrails often coexist in the same assembly, they serve different jobs. But due to the casual use of the terms “handrail” and “guardrail,” the distinction can get blurred in code applications.
At least some of that confusion can be attributed to phrasing in older versions of the code. For example, up through the 2012 IRC, the code used the term “guardrail” without defining it, and referred to the use of a “guardrail or handrail” on the side of a stairway, as if the two served the same purpose and were interchangeable (even then, they were not). The 2015 IRC purged all use of the term “guardrail” and replaced it with “guard”—a term that was already in use and defined—to allay confusion.
There’s nothing in the definition of “guard” that says it has to be the typical railing that comes to the minds of many. Though we’re not talking about decks specifically here, the reason for the change in terminology was so that features on decks such as benches, planters, and built-in kitchens were not precluded from serving as guards. “Handrail” is also defined in the IRC, but it, on the other hand, does require a rail. Here are the definitions in the building code:
Guard: A building component or a system of building components located near the open sides of elevated walking surfaces that minimizes the possibility of a fall from the walking surface to the lower level.
Handrail: A horizontal or sloping rail intended for grasping by the hand for guidance or support.
As the definition implies, guards have only one purpose: They stand as a barrier at the edge of raised walking surfaces to reduce the possibility of an accidental fall. While serving in this protective role, they also invite users to purposefully lean against them or on them. Because of this, features that fit the definition of a guard must be designed to resist minimum required live loads, whether the guard is required or not. However, the architectural limitations of guards, such as minimum height and the size of openings between guard components, only apply to required guards.
A guard is required at any portion of an open-sided walking surface, including stairs, ramps, landings, and decks, that are more than 30 in. above the surface below. And not just immediately below—if the floor or grade below drops more than 30 in. within any point 36 in. out from the edge of the elevated surface, a guard is required. This clarification came into the code to address decks that may be less than 30 in. above grade at their edge, but are located on a downslope or near a retaining wall with a greater drop. Once a guard is required, the minimum height can be no less than 36 in. (with one caveat to come). This is a reduced height from the 42 in. required in commercial buildings, and is a safety trade-off to allow greater visibility for individuals seated on decks. Safety provisions are often reduced for private residences due to occupant familiarity and to protect design freedom in our homes. These dimensions have been unchanged in the code since the 1970s.