Ladder Setup and Roof Access Standard

Purpose

Most roof-access injuries do not happen on a ladder. They happen in the three seconds of getting off it at the top and back onto it at the bottom, when the worker's weight moves sideways off the rungs onto a slope they cannot see under their boots. This procedure fixes the geometry at both ends of that transfer before anyone makes it, and it fixes the one number crews get wrong most often: a ladder that reaches the eave is not a ladder that reaches the landing.

Scope

Covers portable extension and straight ladders used to access a roof, the setup at both ends, and the transfer on and off. Covers duty rating selection and the electrical clearance decision.

Written to the construction rules at 29 CFR 1926.1053, since reroof and tear-off work is construction; on a maintenance visit that is not part of a construction project the general industry ladder rules at 29 CFR 1910.23 apply instead, and the setup geometry below is the same either way. Does not cover stepladders used inside the structure, podium ladders, or ladder jacks and plank staging, which is a work platform rather than access. Does not cover the harness, anchor or clearance calculation, which the fall protection setup SOP owns; that SOP runs after this one because the anchor connection is made at the top of this ladder.

Roles and responsibilities

The geometry both ends have to satisfy

Two rules govern, and they interact. A non-self-supporting ladder is set so the horizontal distance from the base to the supporting surface is a quarter of the working length, the 1:4 angle at 29 CFR 1926.1053(b)(5)(i). And the side rails extend at least 3 ft above the upper landing surface when the ladder is used to reach that landing, at 29 CFR 1926.1053(b)(1).

At that 1:4 angle the vertical rise is the working length times 0.968, since the rise is the square root of the working length squared minus the base offset squared. That factor holds only at the 1:4 setup; flatten the ladder and it drops. So a ladder's usable rise is slightly less than its working length, and its working length is well short of its stamped size, because a two-section extension ladder loses the overlap between sections - commonly 3 ft on ladders up to 32 ft, which is why a stamped 24 ft ladder gives about 21 ft of working length.

                      / top of rails
                     /   3 ft above eave, minimum
      eave  ========/
                   /|
                  / |
   working       /  | rise is 0.968 x working length
   length       /   |
               /    |
      grade   +=====+
              base out = working length / 4

Procedure

1. Pick the placement before you pick the ladder. Stand where the ladder will go and look up, then down. Acceptance: no overhead conductor within 10 ft of the ladder or the climber at any point of the raise or the climb, a base that is level or can be leveled, no door that opens into it, and no vehicle path across the base. Wrong looks like a placement chosen because it is closest to the truck. Stop rule: if a service drop cannot be cleared by 10 ft, do not raise there - relocate, or have the utility cover or drop the line. Hazard: the raise is when a metal ladder reaches its highest arc, and 29 CFR 1910.333(c)(3) sets 10 ft as the minimum approach for an unqualified person at 50 kV and under; where the employee or the ladder could contact exposed energized equipment, 29 CFR 1926.1053(b)(12) requires nonconductive side rails, which reduces the shock risk but does not license working inside that distance.

2. Size the ladder to the landing, not to the eave. Measure eave to grade, add 3 ft, and divide by 0.968 to get the working length needed. Acceptance: the selected ladder's maximum working length equals or exceeds that figure, with the overlap loss already subtracted. Wrong looks like reading the stamped size off the rail and assuming that is the reach. Stop rule: if the longest ladder on the truck is short, do not climb it and do not stand it steeper than 1:4 to gain rise - that is the setup that kicks out. Send for the right ladder or set staging. Hazard: a ladder set past vertical to make up reach fails backwards with the climber on it, and it fails at the top of the climb.

3. Inspect the ladder and confirm the duty rating against the real load. Sight both rails for bends, check every rung for looseness and grease, check the rung locks, the pulley, the rope and the feet. Then read the duty rating label: Type IAA is rated 375 lb, Type IA 300 lb, Type I 250 lb, Type II 225 lb, under the ANSI A14 standards the manufacturer certifies to, and that rating covers the worker plus clothing, tools and anything carried. Acceptance: no defect and the rating exceeds the heaviest climber plus load. Wrong looks like a Type II homeowner ladder under a roofer carrying a bundle. Stop rule: a defective ladder is tagged and removed from service the same day, not leaned in the shop corner. Hazard: a bent rail is usually only visible by sighting down the rail from the foot, which nobody does unless the SOP says to.

4. Set the base and prove the angle. Foot the ladder on firm, level ground or a leveled pad, feet flat and pointing correctly for the surface, and set the base out at a quarter of the working length. Acceptance: measured base offset within a few inches of working length divided by four, both feet bearing, and the ladder does not rock when pushed at the third rung. Wrong looks like one foot on sod and one on a walkway, or a base on wet clay. Stop rule: a base that rocks or sinks gets a solid pad or a different location - never a stack of shingle bundles or a scrap of plywood on soft ground. Hazard: an unsecured base slides out under the horizontal push a climber generates when stepping off at the top, which is exactly when nobody is watching the bottom.

5. Set the top so both rails bear on structure. Land both rails on a solid surface, not on a gutter, and use a standoff or stabilizer where the fascia or gutter is in the way. Acceptance: 3 ft of rail standing above the eave, both rails in contact, no load on the gutter. Wrong looks like rails resting on a K-style gutter that is quietly deforming, which shows up later as a low spot that ponds. Stop rule: no solid bearing means a standoff goes on before anyone climbs; if there is no standoff on the truck, the access point moves. Hazard: aluminum gutter crushed under a rail can let the ladder shift sideways several inches without warning at the moment of transfer.

6. Secure both ends before the first climb. Tie the top to a fixed point, an anchor or a screwed cleat, and secure the base by tying it back or having a person foot it. Acceptance: the ladder will not move laterally when pushed hard at the top by the setter standing on the third rung. Wrong looks like a top tie made to a gutter or a downspout. Stop rule: if the top cannot be tied, a person foots the base for every climb and does not leave that post. Hazard: making the top tie is itself a climb, so it is made from inside the rails with a hand free, never by reaching around the outside.

7. Make the transfer with empty hands and a called move. Climb facing the ladder with three points of contact, hoist tools and material separately by rope, call the move down, and step off between the rails. Acceptance: nothing in either hand on the climb, a verbal call before the step-off, and the fall protection connection made per that SOP before the worker leaves the transfer zone. Wrong looks like a bundle on a shoulder. Stop rule: material carried up by hand goes back down before the climb continues. Hazard: the step-off is a lateral weight shift onto a slope carrying granules or frost, so test the surface with one boot while still holding the rails, and if it slips, step back onto the rung rather than committing.

8. Re-check the setup through the day and take it down deliberately. Look at both ends after lunch, after any delivery, and after any weather change. Acceptance: base offset and both ties still as set, feet still bearing. Wrong looks like a ladder that has walked sideways off its chalk mark, the tell that the base is moving. Stop rule: any movement and the ladder is reset from step 4 rather than nudged back. Hazard: at take-down the ladder is at its longest with nobody on it to steady it, so lower the fly section before walking it down, and keep step 1's 10 ft conductor clearance on the way down as on the way up.

The record this produces

A roof access line on the job ticket, written once at setup: date and address; measured eave height; working length required and the ladder actually used; base offset as measured; how the top was secured and to what; how the base was secured; whether a standoff was used; and any stop rule that fired with the substitution made.

The next crew to that address reads it and does not repeat the trip for the longer ladder. The office reads it if a gutter dents or a fall is reported, because "top tied to a screwed cleat at the north gable, standoff used" is a specific defensible statement and "we set the ladder" is not.

Worked pass: two-story gable, north elevation

Eave measures 18 ft 0 in to grade. Step 2 arithmetic: 18 plus 3 is 21 ft of rise required, divided by 0.968 gives 21.7 ft of working length required. The crew pulls the stamped 24 ft extension ladder, whose two 12 ft sections overlap by 3 ft, giving 21 ft of working length.

Step 2 fails. At 21 ft of working length the rise is 21 times 0.968, or 20.3 ft, which puts the top of the rails 2.3 ft above an 18 ft eave. That is under the 3 ft the standard requires, and the stop rule forbids steepening the ladder to make up the difference. The crew swaps to the stamped 28 ft ladder, two 14 ft sections with the same 3 ft overlap, giving 25 ft maximum working length. They extend it to 22 ft: rise is 21.3 ft, 3.3 ft above the eave, and base offset is 22 divided by 4, or 5 ft 6 in. Both numbers go on the ticket, including the failed one, because the next crew at this address needs to know the 24 ft ladder does not reach.

Step 1: service drop enters at the south-west corner, more than 10 ft from the north placement. Step 3: Type IA at 300 lb, climber plus belt well under. Step 4: offset measured at 5 ft 5 in on a leveled pad over a garden bed, no rock at the third-rung push. Step 5: aluminum K-style gutter present, so a standoff goes on and both rails bear on the fascia with no load on the gutter. Step 6: top tied to a screwed cleat in the fascia, base tied back to a stake. Step 8: after the afternoon material drop the offset re-measures 5 ft 9 in, outside tolerance, so the ladder is reset from step 4 rather than pushed back, and the reset is noted.

One check the general section forces: the 5 ft 6 in offset comes from the 22 ft actually set, not from the 25 ft the ladder can reach. Extending to 25 ft would have put the rails 6.2 ft above the eave, legal but springy and awkward to transfer past, and it would have needed a 6 ft 3 in offset. The working length set is the one the offset is calculated from, every time.

References

• 29 CFR 1926.1053, portable ladders in construction, including the 1:4 setup angle at (b)(5)(i), the 3 ft landing extension at (b)(1), and the nonconductive side rail requirement at (b)(12)
• 29 CFR 1910.23, general industry ladder requirements, which govern maintenance work that is not part of a construction project
• 29 CFR 1910.333(c)(3), minimum approach distance for unqualified persons working near overhead lines
• ANSI A14 ladder series, in the edition the manufacturer certified the ladder to, which binds the maker and reaches you through the duty-rating label on the rail
• See related: the fall protection setup SOP, which owns the anchor and clearance work that begins at the top of this ladder