Most of the building codes require outdoor stair railing to be between 34 inches and 38 inches above the stair nosing. This means that the height of a handrail is measured from the top of the treads, or step-by-step horizontal members. The upper part of the handrail is the upper limit of this measurement. Even if it includes a decorative molding or gripping surface applied on the upper part of the structural part of the track and vertical uprights.
In addition to the provisions of local building codes, the Americans with Disabilities Act addresses external stairs and ramp railings. The ADA states that outdoor stair railing must be within the normal range of 34 inches to 38 inches. It is also required that all railings keep the height constant over nosings stairs. And are free of peaks or surfaces that prevent proper use.
In addition to the height of a railing, the space between the wall and the railing, known as railing clearance, is also important. Building codes and ADA regulations require a minimum distance of 1.5 inches when railings are attached to a wall rather than vertical uprights that are part of the staircase. External railing height requirements are not necessarily the same as height and space requirements for internal stair rails. Make sure you have the latest code information from your local building code office before purchasing the materials or building an exterior stair hand railing.