Recommended Railing Height for Stairs

Codes

• Local and state building codes define building standards. These codes demand that contractors obtain permits and inspections when constructing stairs and railings. Jurisdictions model their requirements either directly or with some modification from the International Building Code, also called the IBC or I-Codes. The International Code Council, a nonprofit organization, creates these rules to “protect the health, safety and welfare of people.” Federal agencies such as the Department of State and the General Service Administration also follow these codes.

Basics

• According to the IBC, the gripping surfaces of railing must be from 34 to 38 inches above the walking surfaces of a stairway. They must be at least 1 1/2 inches from adjacent surfaces to allow continuous gripping throughout the rail. Handrail surfaces must be continuous within the full length of each flight, uninterrupted by posts or other obstructions, and must not have sharp or abrasive parts. The cross sections of circular rails must be from 1 1/4 to 2 inches in diameter. If the cross sections are not circular, then the maximum cross section is 2 1/4 inches, with a perimeter from 4 to 6 1/4 inches.

ADA

• The Americans with Disabilities Act defines slightly different standards for railings so people with disabilities can safely negotiate stairs. It also puts the height of rails at from 34 to 38 inches, with a further requirement that they be at a consistent distance above all walking surfaces. Clearances and cross-sections follow IBC basics. Both the ADA and IBC also define the handrails of ramps as extending at least 12 inches beyond the top and bottom of a run. These extensions must return to the wall, guard or floor, or remain continuous with the handrail of an adjacent run.

One City's Approach

• The codes of Portland, Oregon, form examples of how a local jurisdiction follows and modifies the IBC to suit its needs. Handrails are required on stairways with more than three risers. They must be a minimum of 34 inches high. Any intermediate or decorative rails between the top rail and the bottom rail must have a pattern or spacing that prevents a 5-inch sphere from passing through -- that is the average size of a child’s head. Rails must be at least 1 1/2 inches away from any adjacent surfaces, and might project over steps by a maximum of 4 1/2 inches on each side of the stairs.