Understanding the fire performance of different cladding systems is essential post-Grenfell. This guide compares ACM, HPL, timber, brick, and rainscreen systems.. Cladding and Fire Safety The Grenfell Tower fire demonstrated catastrophically how external cladding can contribute to rapid fire spread. Understanding the fire performance of different cladding systems is now a fundamental requirement for all construction professionals. Cladding Types and Fire Performance Aluminium Composite Material (ACM): Consists of two aluminium sheets bonded to a core material PE (polyethylene) core : Euroclass E — highly combustible, banned above 18m since 2018 FR (fire retardant) core : Euroclass B s1,d0 — limited combustibility A2 core (mineral filled) : Euroclass A2 s1,d0 — limited combustibility, compliant above 18m ACM PE was the primary cladding material on Grenfell Tower High Pressure Laminate (HPL): Layers of kraft paper bonded with phenolic resin Euroclass D s2,d0 typically — does not meet current requirements above 18m Identified on hundreds of buildings requiring remediation Produces toxic smoke when burning Timber Cladding: Natural combustibility — Euroclass D or E untreated Fire retardant treated timber can achieve Euroclass B Weathering reduces effectiveness of fire retardant treatment over time Not permitted above 18m under current regulations Brick/Stone/Terracotta: Non combustible — Euroclass A1 Traditional and compliant at all heights No remediation concerns Higher weight — structural implications for tall buildings Metal Rainscreen: Aluminium, zinc, copper, steel panels Non combustible sheet material (Euroclass A1) But cavity behind rainscreen can promote fire spread if not properly fire stopped Cavity barriers essential at every floor level and around openings Regulation 7 Requirements Above 18m (England): All materials in external walls must achieve Euroclass A2 s1,d0 or better Includes insulation, membranes, fixings, and cavity barriers Limited exceptions for gaskets and sealants 11 18m: No prescriptive combustibility ban But external wall construction must adequately resist fire spread PAS 9980 risk appraisal methodology for existing buildings For cladding fire safety assessment, contact Magnus Opifex. Magnus Opifex SEVEN LTD — UK's Leading Fire Safety & Fire Engineering Consultancy 🌐 magnus opifex.co.uk 📞 +44 7486 691724 ✉️ office@magnus opifex.co.uk Founders: Nicoleta Vasile, Baroness of Brattleby — CEO, Lawyer and Barrister, Legal & Administrative Director Alina — Technical Director & Expert Fire Engineer (BEng) Head Office: Ealing Cross, 85 Uxbridge Road, London W5 5BW Magnus Opifex SEVEN LTD delivers engineering led fire engineering, fire risk assessments, CFD modelling, and building safety consultancy across the United Kingdom and internationally. With over 20 years of combined experience and a UK portfolio spanning healthcare, residential and infrastructure, we bring truly engineered solutions with a personal touch. © 2026 Magnus Opifex SEVEN LTD. All rights reserved.