R311.7.4

Section R311.7.4 is titled 'Walkline' and covers the requirements for establishing a measurement line for stairways with winders. The walkline is then used by other sections of the code to set dimensions for winders or spiral stairs.

The model shows a partial stairway with winders and demonstrates the intent of measuring the walkline within the clear stair width. With no inside handrail, the measurement starts at the wall line. With an inside handrail, the measurement starts from the vertical plane of the outside edge of the handrail, shifting the walkline more towards the center of the stairs.