FIR/Specific/TBT-FIR-009

Cladding and Insulation Fire Risk

Fire SafetySpecificCladding and Insulation Fire Risk

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Cladding and Insulation Fire Risk

Toolbox Talk Record

Ref: TBT-FIR-009  |  Issue: 1  |  Date: March 2026
PresenterProject
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What?

  • Combustible cladding and insulation materials contributed to the Grenfell Tower fire in June 2017.
  • The Building Safety Act 2022 introduced stricter requirements for external wall materials on all buildings.
  • Materials with a Euroclass below A2 are banned on buildings over 18 metres under the amended Building Regulations.
  • During construction, exposed insulation and partially completed cladding systems are highly vulnerable to fire.
  • Combustible insulation includes PIR, phenolic foam, and EPS — all burn rapidly when ignited.
  • Hot works near exposed insulation is one of the most common causes of cladding fires during construction.
  • Fire breaks and cavity barriers within cladding systems must be installed as the work progresses.
  • The Regulatory Reform (Fire Safety) Order 2005 requires fire risk management during the construction phase.
  • Waste insulation and packaging materials left on scaffolds create additional fuel for any fire.
  • A construction phase fire strategy must address cladding and insulation risks specifically.

Why?

Rapid fire spreadCombustible cladding and insulation allow fire to spread across entire building facades.
Post-Grenfell dutiesThe Building Safety Act imposes strict new duties on material selection and installation.
Construction vulnerabilityPartially installed cladding is more fire-vulnerable than completed systems.
Life safetyCladding fires in occupied or partially occupied buildings endanger residents and workers.
Do Don't
  • Verify the fire classification of all cladding and insulation materials before installation.
  • Install cavity barriers and fire breaks progressively as cladding installation proceeds.
  • Keep combustible insulation and cladding waste off scaffolds and away from ignition sources.
  • Obtain a hot works permit before any work near exposed insulation or cladding.
  • Store combustible insulation materials in a secure area away from the building facade.
  • Follow the construction phase fire strategy for cladding and insulation risks.
  • Brief all trades on the fire risks of working near exposed insulation materials.
  • Maintain fire extinguishers on every scaffold lift where cladding work is underway.
  • Report any missing or displaced cavity barriers to the site manager immediately.
  • Comply with the Building Safety Act requirements for external wall material selection.
  • DON'T install cladding materials that do not meet the specified fire classification.
  • DON'T carry out hot works near exposed insulation without a hot works permit.
  • DON'T leave combustible insulation offcuts or packaging on scaffold platforms.
  • DON'T skip cavity barrier installation — they are critical to preventing fire spread.
  • DON'T store large quantities of combustible insulation adjacent to the building.
  • DON'T ignore the construction phase fire strategy for cladding activities.
  • DON'T substitute specified materials with cheaper alternatives without design approval.
  • DON'T allow smoking on scaffold platforms near exposed insulation materials.
  • DON'T leave partially completed cladding systems unprotected overnight.
  • DON'T assume modern insulation does not burn — many types are highly combustible.

See also: Fire Safety Awareness on Site | Fire Door and Compartmentation

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