Understanding fire stopping systems — from linear gap seals to service penetrations — and why third-party certification is essential for compliance.. What is Fire Stopping? Fire stopping refers to the sealing of openings and gaps in fire resisting elements (walls, floors, and ceilings) to maintain their fire resistance. Without effective fire stopping, even the best designed compartmentation is compromised, allowing fire and smoke to spread through service penetrations, construction joints, and movement joints. Why Fire Stopping Matters The Grenfell Tower Inquiry and subsequent investigations have highlighted widespread failures in fire stopping across UK buildings: Missing fire stopping at floor/wall junctions Incorrect products used for specific applications Poor workmanship and installation quality No inspection or sign off of concealed fire stopping Degradation of fire stopping over building lifetime Types of Fire Stopping Penetration Seals Sealing around services passing through fire resisting elements: Pipe penetrations — plastic, metal, and composite pipes Cable penetrations — individual cables, cable bundles, and cable trays Duct penetrations — HVAC, kitchen extract, and smoke control ducts Busbar and cable tray — large electrical distribution systems Linear Gap Seals Head of wall joints — between partition top and structural slab Wall to wall junctions — between different wall constructions Curtain wall perimeter — between curtain wall and floor slab Movement joints — accommodating structural movement while maintaining fire resistance Fire Stopping in Cavities Cavity barriers in external wall systems Fire barriers in roof voids Dampers in ductwork passing through compartment boundaries Product Selection Intumescent Products Intumescent sealants — expand when heated to seal gaps Intumescent wraps and collars — for plastic pipe penetrations Intumescent pillows — removable fire stopping for cable transits Intumescent boards — for large openings and builders' work holes Non Intumescent Products Mineral wool packing — with intumescent sealant facing Mortar and concrete — for permanent, large scale fire stopping Ceramic fibre products — for high temperature applications Ablative coated batts — for cable penetrations in power stations Third Party Certification Fire stopping products and installations should be third party certified: Product Certification CERTIFIRE — product certification based on fire testing BBA Certification — agrément certificates for construction products Warrington/Exova — fire testing and product approval Installer Certification FIRAS — fire stopping installation certification scheme IFC Certification — installation quality scheme BRE Global — installer competence certification Using certified installers is increasingly required by building control bodies and insurers. Inspection and Documentation During Construction Photographic evidence of all fire stopping before concealment As installed records showing product type, location, and installer Quality checks against manufacturer's installation instructions Independent inspection by fire stopping specialist In Use Buildings Regular inspection of accessible fire stopping Re inspection after building alterations or maintenance work Condition assessment of aged fire stopping materials Remediation programme for deficient fire stopping Our Fire Stopping Services Magnus Opifex SEVEN LTD provides fire stopping survey, specification, and inspection services. Our fire engineers assess existing fire stopping installations, specify appropriate products for new construction, and inspect installed fire stopping to ensure compartmentation integrity is maintained throughout the building lifecycle. 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.