Ladders are the most common way to reach a roof and a frequent source of serious falls. Rules for portable ladders are broadly similar across jurisdictions, and most roofing safety programmes teach the same core practices.
The 4-to-1 rule
A straight or extension ladder should be set so that its base is one unit out from the wall for every four units of height to the top support. The US OSHA construction standard, 29 CFR 1926.1053, expresses this as a horizontal distance equal to one-quarter of the working length of the ladder, which gives an angle of about 75 degrees. Canadian industry guidance allows a horizontal-to-vertical ratio between 1/4 and 1/3.
Extension above the roof
For access to a roof, OSHA requires the side rails to extend at least 3 ft (0.9 m) above the upper landing; where that is not possible, a secure grab rail must be provided. Canadian guidance specifies at least 900 mm (3 ft) above the landing or roof edge.
Securing
- Set the base on firm, level footing with non-slip feet.
- Tie off the top to the structure, and secure the bottom against slipping.
- On extension ladders, overlap the sections by at least three rungs, or more if the manufacturer requires.
- Do not set up or extend a ladder in doorways or driveways without barricades.
Use
- Face the ladder when climbing, keep a firm handhold and do not carry loads that prevent holding on; hoists or ladder lifts are used to raise materials.
- Do not stand on the top two steps of a stepladder.
- Choose a ladder rated for the user, tools and materials.
Inspection and electrical hazards
Ladders are inspected before use and after any incident; defective ladders are tagged and taken out of service. Canadian guidance says aluminium ladders must not be used near overhead power lines, and OSHA requires non-conductive side rails where a ladder could contact energised equipment.
Roof ladders
On steep pitched roofs, separate roof ladders with hooks over the ridge, and roof brackets with planks, provide footing on the slope itself.
Sources
Reviewed 2 November 2026 · 3 sources · Editorial policy · Plain-text version · Suggest a correction
- OSHA Ladder Requirements: 29 CFR 1910.23 and 1926.1053 ExplainedWC Safety · wcsafety.com
- Canadian Roofing Reference Manual: 1.7.1 LaddersCanadian Roofing Contractors Association · roofingcanada.com
- Roof workHealth and Safety Executive (UK) · hse.gov.uk