Torch-on bitumen roofing involves using an open gas flame to heat and bond felt membranes to a roof deck. This creates a significant fire risk, particularly on combustible decks, near insulation, and on timber-framed buildings. Several major construction fires in the UK have been caused by torch-on roofing work. This talk covers the specific fire risks and the controls required for safe torch-on application.
Key Hazards
Roof deck fire from flame contact with combustible insulation or timber substrate
Building fire spreading through cavities ignited by torch heat penetration
Burns to operatives from direct flame contact or hot bitumen splash
Gas cylinder leak or failure causing fire or explosion on the roof
Control Measures
Obtain a hot works permit before any torch-on roofing work begins on site.
Confirm the roof deck construction and check whether combustible materials are present beneath.
Use a flame-free bonding system on combustible roof decks where specified by the fire risk assessment.
Keep gas cylinders upright, secured, and at least three metres from the flame source during use.
Maintain a fire extinguisher and fire blanket within immediate reach of the torch operator at all times.
Clear the roof of all loose combustible materials before starting torch-on application.
Carry out a fire watch for at least 60 minutes after torch-on work is completed each day.
Inspect the underside of the roof deck from below during and after torch-on application where accessible.
Brief all operatives on the evacuation route from the roof and the nearest fire alarm call point.
Emergency / Rescue
If the roof deck ignites, raise the fire alarm immediately and evacuate the roof. Attempt to extinguish only small fires with the available extinguisher. Call 999 and direct the fire service to the roof access point on their arrival.
Remember
A hot works permit is mandatory before any torch-on bitumen roofing work begins
Check the roof deck construction for combustible materials beneath before using a torch
Gas cylinders must be upright, secured, and kept at least three metres from the flame
A fire watch of at least 60 minutes is required after torch-on work finishes each day
Know the evacuation route from the roof and the nearest fire alarm call point before starting
Applicable Legislation: Regulatory Reform (Fire Safety) Order 2005 · CDM Regulations 2015 · Health and Safety at Work etc. Act 1974 · BS 8217 (Reinforced Bitumen Membranes)