610 – Bathtubs Quick Guide

610.2 Bathtub Seats. 
The top of bathtub seats shall be 433 mm (17″) minimum and 485 mm (19″) maximum above the bathroom finish floor.  The depth of a removable in-tub seat shall be 380 mm (15″) minimum and 405 mm (16″) maximum.  The seat shall be capable of secure placement.  Permanent seats at the head end of the bathtub shall be 380 mm (15″) deep minimum and shall extend from the back wall to or beyond the outer edge of the bathtub.

610.3 Shower Compartment Seats.
Where a seat is provided in a standard roll-in shower compartment, it shall be a folding type, shall be installed on the side wall adjacent to the controls, and shall extend from the back wall to a point within 75 mm (3″) of the compartment entry.  Where a seat is provided in an alternate roll-in type shower compartment, it shall be a folding type, shall be installed on the front wall opposite the back wall, and shall extend from the adjacent side wall to a point within 75 mm (3″) of the compartment entry.  In transfer-type showers, the seat shall extend from the back wall to a point within 75 mm (3″) of the compartment entry.  The top of the seat shall be 430 mm (17″) minimum and 485 mm (19″) maximum above the bathroom finish floor.  Seats shall comply with 610.3.1 or 610.3.2.

610.4 Structural Strength.
Allowable stresses shall not be exceeded for materials used when a vertical or horizontal force of 250 pounds (1112 N) is applied at any point on the seat, fastener, mounting device, or supporting structure.