PDFWAC 296-874-20024
Make sure stairway-type ladders meet these requirements.
(1) You must make sure stairway-type ladders meet all of the following:
(a) Position the bottom step not more than twenty-four inches (61 cm) above the scaffold supporting level;
(b) Have rest platforms not more than twelve feet (3.7 m) apart vertically;
(c) Have slip-resistant surfaces on treads and landings;
(d) Have steps that:
(i) Are at least sixteen inches (41 cm) wide; and
(ii) Line up vertically between rest platforms.
(2) You must make sure mobile ladder stands have steps that are at least eleven and one-half inches (30 cm) wide.