Building Code Guide for Stair Railings

Foundation

• In one sense, the country boasts thousands of building codes, since all state and many local jurisdictions manage their own. In another sense, the country only has one set, since building authorities generally take their rules either verbatim or with modifications from the International Code Council (ICC).

  Founded in 1994, this nonprofit organization streamlined a hodge-podge of duplicate and sometimes conflicting construction standards into the current single set. The ICC also runs educational and certification programs, sells technical handbooks and workbooks, reviews plans and publishes proposed code changes.

IBC

• The International Building Code (IBC) lays the foundation for all other codes, since it applies to residences, commercial buildings, educational institutions, government offices and other structures.

  Specific provisions for stair railings include requiring two handrails, one on each side, except for stairways within dwelling units and spiral staircases having handrails on one side only, or elevations with three or fewer risers within residential units, which do not require any handrails. These must have a height of 34 to 38 inches, as measured from the edges of stair steps or from a ramp slope.

  Handrails transitioning between flights can exceed these requirements.

IRC

• The International Residential Code (IRC) applies to one- and two-family dwellings, though many of its provisions duplicate those in the IBC. In both codes, handrails with a circular cross section must have an outside diameter of 1.25 to 2 inches. Those without circular dimensions need a perimeter dimension of 4 to 6.25 inches, with a maximum cross-section dimension of 2.25 inches.

  One difference requires handrails on only one side of the stairs.

ADA

• The Americans with Disabilities Act (ADA) adds to all state building codes and modifies IBC and IRC codes so the disabled have access standards. Its guidelines are mandated for public spaces that require disabled accessibility, but is optional for private residences, unless disabled homeowners require the guidelines.

  The ADA specifies that handrails are needed on both sides of the stairs, and must be continuous for the full flight of stairs. However, switchback or dogleg stairs must have handrails that are also continuous between flights. Height standards must follow those in the IBC, except for handrails designed for children, which must have a maximum height of 28 inches. Upper and lower handrails require a minimum clearance of 9 inches between them.