Window Washing Guide
TOOL 23 / 23
◆ Specialist Practice · The Ladder Safety Calculator

More trade injuries come from ladders
than from any other equipment.

Nine inputs — ladder type, working height, setup angle, base surface, footing, reach, weather, crew, rail condition — assemble a safety score. Five hard-override conditions supersede the score for the documented catastrophic failure modes: rail damage, wet aluminum near electrical, lightning, extended reach at height, and rails on glass.

◇ Working height of the panel
14feet · 4:1 base offset = 3.5 ft
STEP LADDERRESIDENTIAL (16 FT)FALL-ARREST LINE (40 FT)
◇ Ladder type
◇ Setup angle (base offset)
◇ Base surface under the feet
◇ Top-rail footing support
◇ Reach beyond the centerline
◇ Weather and wind
◇ Solo or teamed
◇ Visible ladder condition
◆ SAFE — SETUP IS WITHIN THE WORKING ENVELOPE

The configuration is in the safe envelope.

proceed with the planned work

Safety score: 14/100. The combination of ladder type, working height, setup angle, base surface, footing support, reach, weather, crew, and rail condition lands in the safe band where documented incident rates are at their lowest. Continue with the planned work; maintain the routine pre-work checks (rail inspection, base stability test, equipment-clear-of-electrical confirmation).

SAFETY SCORE
14/ 100
4:1 BASE OFFSET
3.5ft
HARD-OVERRIDE
◆ Companion reference
ENCYCLOPEDIA
Working at height: a safety primer for the residential window cleaner
THE TOOLS
The Pole Reach Calculator — the pole side of the same question
THE TOOLS
The Scratch Risk Calculator — substrate and method risk