Ladder, stair and walkway checker
Enter the dimensions of a fixed ladder, a stair or a walkway and see each requirement of the chosen rule, with its clause, before the FRP ladder, stair treads or grating are detailed.
- Ladders
- OSHA · EN ISO 14122-4
- Stairs
- OSHA · EN ISO 14122-3 · IBC
- Walkways
- EN ISO 14122-2
Clear width is measured between the inside faces of the side rails, so it is the overall width minus both rails. Australia and New Zealand (AS 1657:2018) and Canadian provincial rules are not encoded; check their limits on the drawing.
- Rung spacingMeets300 mm (11.8 in)10 to 14 in (254–356 mm), centerline to centerline · 1910.23(b)
- Clear width between side railsMeets420 mm (16.5 in)At least 16 in (406 mm) for fixed ladders · 1910.23(b)
- Clearance behind the rungsMeets180 mm (7.1 in)At least 7 in (178 mm) from the rung centerline to the nearest permanent object · 1910.23(d)
- Side-rail extension at the topMeets1070 mm (42.1 in)42 in (1,067 mm) above the access level for through and side-step ladders, or grab bars · 1910.23(d)
- Fall protectionMeets6.00 m (19.7 ft)Not required: the ladder does not extend more than 24 ft (7.3 m) above the lower level · 1910.28(b)(9)
A geometry check against the listed clauses only. Loads, fixings, the fall protection system and the complete drawing are reviewed for the rule adopted on the site.
Before you detail an FRP access system
Geometry is only one part. The fall protection concept, the loads on rungs, treads and grating, the fixings and the substrate are designed for the same rule. The fixed ladder requirements guide explains the OSHA timeline and the EN ISO 14122-4 cage rules, and the handrail load check covers the guardrails at platform edges and stairs.
Frequently Asked Questions
Which rules does the checker cover?
Fixed ladders to OSHA 1910.23 and 1910.28(b)(9) or EN ISO 14122-4; stairs to OSHA 1910.25 (standard and ship stairs), EN ISO 14122-3 or IBC 2024 §1011; walkways to EN ISO 14122-2, with the ASCE 7-22 and OSHA floor-load references for the grating. AS 1657:2018 for Australia and New Zealand and the Canadian provincial rules are named but not encoded yet, so check their limits on the drawing.
Do cages still count as fall protection on US fixed ladders?
Only on existing ladders. A fixed ladder more than 24 ft above the lower level that was installed on or after 19 November 2018 needs a ladder safety system or a personal fall arrest system. Existing cages remain acceptable until the ladder or cage is replaced and until 18 November 2036. OSHA proposed in April 2026 to remove the 2036 date; until a final rule is published, plan for it.
Why does one ladder design rarely fit both the US and Europe?
OSHA spaces rungs 10 to 14 in apart and requires at least 16 in clear width, while EN ISO 14122-4 uses a 225–300 mm rung pitch and a 400–600 mm clear width, and it still accepts a cage above a 3 m fall height where OSHA does not for new ladders. State the destination rule on the drawing before the side rails are cut.
How is the grating opening checked?
EN ISO 14122-2 does not let a 35 mm ball pass through the walking surface, or a 20 mm ball where people or workstations are below. For a square-mesh molded grating the clear opening is the mesh pitch minus the top bar width, about 32 mm for the 38.1 mm mesh. Where the smaller ball applies, a solid top or cover plate closes the openings.