Cladding & Insulation Risks Explained

Learn how these issues impact your insurance and protect your property.

Why Cladding & Insulation Matter to Insurers

Since the tragic Grenfell Tower fire in 2017, cladding and insulation materials have become a major concern for insurers. Whether you own a residential block, commercial unit, or mixed-use building, insurers now require full disclosure of:

  • The type of external cladding used
  • The insulation material beneath or behind the cladding

Failing to provide this information — or providing incorrect details — can lead to:

  • Higher premiums
  • Cover exclusions
  • Declined claims or refusal to quote

This guide breaks down the common materials, how to identify them, and how to stay compliant.

Download the Guide

Common Cladding Types

  1. ACM (Aluminium Composite Material)
  • Thin aluminium sheets with a polyethylene (plastic) core
  • Widely used pre-Grenfell on high-rise and modern buildings

Risk: Extremely flammable in some forms — high fire risk

Insurance Note: Many insurers will not accept this unless removed or replaced

  1. HPL (High-Pressure Laminate)
  • Compressed wood or paper layers with a resin binder

Risk: Can be combustible depending on insulation used and installation

Insurance Note: Must be declared and may require risk assessments

  1. Timber Cladding
  • Visually attractive, especially on low-rise or eco builds

Risk: Flammable — fire risk can be managed with fire breaks and fire-retardant treatment

Insurance Note: Accepted with additional safety measures and limited height

  1. Brick Slips / Masonry Cladding
  • Real brick veneer applied to exterior walls

Risk: Low fire risk – considered safe and durable

Insurance Note: Usually favourable to insurers

  1. Render Systems (e.g., EWI)
  • Render applied to insulation board (External Wall Insulation)

Risk: Depends on insulation type used underneath

Insurance Note: Must be paired with non-combustible insulation for best results

Common Insulation Types (Behind Cladding)

Rockwool / Mineral Wool

  • Non-combustible
  • Good fire performance

Insurance View: Low risk, often preferred

Expanded Polystyrene (EPS)

  • Lightweight and cheap
  • Highly combustible if exposed to fire

Insurance View: May result in cover refusal or higher excess

Polyisocyanurate (PIR)

  • High thermal performance
  • Combustible if not properly fire stopped

Insurance View: May be acceptable with fire break systems

Phenolic Foam (e.g., Kingspan Kooltherm)

  • Good thermal rating, low smoke emission

Insurance View: Higher scrutiny post-Grenfell – may need fire reports

How to Find Out What You’ve Got

If you’ve purchased a building or manage one with unclear records:

Start with your building documents:

  • EPC reports
  • Fire Risk Assessments (FRA)
  • Planning/building control documents
  • Leaseholder packs or O&M manuals

Get a Fire Engineer or Surveyor

  • Commission a cladding material and insulation survey
  • Look for an EWS1 form (External Wall System Assessment) – especially for residential buildings over 18m tall

Photograph Visible Areas

  • Cladding panels, fixings, insulation (if exposed)
  • Share with your broker or surveyor for help with identification

Why Insurers Need This Info

  • Fire safety is a critical risk factor for underwriters
  • Accurate details allow insurers to set fair terms and respond to claims
  • Incomplete or false declarations may invalidate cover

Even if you “don’t know” – insurers need that flagged. We can help guide how to state this properly to avoid issues.

How Qudos Can Help

  • Guide you through identifying your materials
  • Liaise with underwriters on non-standard construction
  • Place cover with insurers that accept specific cladding/insulation types
  • Work with your surveyors or fire engineers