ScaFixTypes of scaffolding
Scaffold ladders and access: what OSHA requires
OSHA's access paragraph is one of the most specific in Subpart L: it gives rung lengths, rung spacing, rest platforms and the gap you may step across. Here it is, rule by rule, with what the Work at Height Regulations add in Great Britain and how a planned scaffold gets its ladders.
By Ole Emil Frikstad Urstad · How the numbers are computed ·
When does a scaffold need a ladder?
Under 29 CFR 1926.451(e)(1), a scaffold platform more than 2 ft (0.6 m) above or below the point of access needs a proper means of access: a ladder, stair tower, ramp or integral access frame. Cross braces never count. Hook-on and attachable ladders start no more than 24 in above the base; above 35 ft they need rest platforms.
The access options OSHA accepts
Paragraph (e)(1) lists them: portable ladders, hook-on ladders, attachable ladders, stair towers, stairway-type ladders such as ladder stands, ramps, walkways, integral prefabricated scaffold access, or direct access from another scaffold, structure, personnel hoist or similar surface. The same sentence closes the door on the most tempting shortcut: «Crossbraces shall not be used as a means of access».
| Access type | Key dimensions | Where |
|---|---|---|
| Hook-on and attachable ladders | Bottom rung no more than 24 in (61 cm) above the supporting level; rungs at least 11½ in (29 cm) long; uniform spacing, no more than 16¾ in apart; designed for the scaffold type | 1926.451(e)(2) |
| Rest platforms on ladders | At 35 ft (10.7 m) maximum vertical intervals on supported scaffolds more than 35 ft high | 1926.451(e)(2)(iii) |
| Stairway-type ladders | Bottom step no more than 24 in up; rest platforms every 12 ft (3.7 m); steps at least 16 in wide (11½ in on mobile scaffolds); slip-resistant treads | 1926.451(e)(3) |
| Stair towers | Stairrail of toprail and midrail on each side, 28–37 in above the tread; landing at least 18 × 18 in at each level; stair at least 18 in wide; 40°–60° from horizontal | 1926.451(e)(4) |
| Ramps and walkways | Guardrails from 6 ft above a lower level; no steeper than 1 in 3; cleats at most 14 in apart when steeper than 1 in 8 | 1926.451(e)(5) |
| Integral access frames | Rungs at least 8 in long, no more than 16¾ in apart; not a work platform when rungs are under 11½ in unless fall protection is used; rest platforms every 35 ft | 1926.451(e)(6) |
| Direct access from another surface | Only when the scaffold is no more than 14 in (36 cm) away horizontally and 24 in (61 cm) vertically | 1926.451(e)(8) |
Scaffold ladders in Great Britain
In Great Britain the ladder rules sit in Schedule 6 of the Work at Height Regulations 2005, and they start one step earlier than OSHA: a ladder may be used for work at height only if a risk assessment shows that more suitable equipment is not justified, because the risk is low and the use short, or because of site features the employer cannot change. For a ladder used as scaffold access, the schedule adds:
- A stable, firm surface of sufficient strength, so that the rungs stay horizontal (paragraph 2).
- A portable ladder prevented from slipping by securing the stiles at or near the top or bottom, an effective anti-slip or stability device, or an equivalent arrangement (paragraph 5).
- An access ladder long enough to protrude sufficiently above the landing, unless other measures give a firm handhold (paragraph 6).
- Where a ladder or a run of ladders rises 9 m or more above its base, safe landing areas or rest platforms at suitable intervals, where reasonably practicable (paragraph 9).
- A secure handhold and secure support always available to the user (paragraph 10).
Access during erection, and a practical order of work
Erectors are covered by their own paragraph, (e)(9). A competent person decides whether safe access is feasible during erection; hook-on or attachable ladders go in as soon as the scaffold has progressed far enough to install and use them. On tubular welded frame scaffolds, the end frames themselves may be climbed during erection and dismantling if their horizontal members are parallel, level and no more than 22 in apart vertically, but the cross braces may never be used to get on or off.
- Decide where the ladder bay goes before the first lift, usually at one end of the run and clear of doors and the material hoist.
- Fix the ladder to the scaffold so that it cannot tip it, with the bottom rung within 24 in of the base.
- Put a hatch deck at each lift the ladder passes, and keep the hatch closed when nobody is climbing.
- Above 35 ft of climb, add a rest platform, and line the rungs up vertically between rest platforms (1926.451(e)(7)).
How ScaFix plans the ladders on a wall
| Part | Length | Pieces |
|---|---|---|
| Frames | 6'-4" | 12 |
| Frames | 3'-3 1/2" | 2 |
| Top-lift guardrail posts | 2 | |
| Decks without ladder | 10' | 6 |
| Decks with ladder | 10' | 3 |
| Front guardrails | 10' | 12 |
| Toeboards | 10' | 9 |
| Diagonals | 10' | 18 |
| End guardrails | 6 | |
| Wall ties | 8 | |
| Wall-anchor fittings | 8 | |
| Base jacks / legs | 8 |
What the example shows
The 3 decks with a ladder are the access: one per decked lift, stacked in the same bay so the rungs line up. On a longer wall a second ladder bay shortens the walk to the ladder; where the crew carries material up and down all day, a stair tower is the better access (in ScaFix, stair towers are part of Pro).
Questions and answers
Can you climb the cross braces of a scaffold?
No. 1926.451(e)(1) says cross braces shall not be used as a means of access, and (e)(9)(iv) repeats it for erectors on tubular welded frame scaffolds.
How far apart can scaffold ladder rungs be?
Hook-on and attachable ladders and integral access frames have uniformly spaced rungs no more than 16¾ in apart. Ladder rungs must be at least 11½ in long; integral access frame rungs at least 8 in.
When does a scaffold ladder need a rest platform?
On supported scaffolds more than 35 ft high, hook-on and attachable ladders and integral access frames get rest platforms at 35 ft maximum vertical intervals. Stairway-type ladders get them every 12 ft.
Can I step onto the scaffold from a roof or a window?
Only if the scaffold is no more than 14 in away horizontally and 24 in vertically from that surface (1926.451(e)(8)).
Sources
Federal text as published on the eCFR and the UK regulations as published on legislation.gov.uk, read on 25 October 2026. A planned ladder layout is planning information, not a structural approval or an inspection.
Limits
- The number of wall ties follows the system's tie rule. Their positions must be checked against the manufacturer's assembly instructions.
- Round corners, silos and hanging scaffolds are in Pro. A round scaffold is not a standard configuration and needs a calculation or the supplier's documentation. A hanging scaffold (Layher Allround and HAKI Universal) always needs a structural calculation from the supplier or an engineer.
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