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Passive Fire Protection FAQs

Frequently Asked Questions

Specifying passive fire protection means getting the detail right, from cavity barriers and fire stopping through to the test evidence behind every product. We’ve pulled together the questions our technical team gets asked most, with straightforward answers you can act on.

Tenmat has manufactured passive fire protection in the UK for over 100 years, developing our own high performance intumescent technology in-house in Manchester. The answers below are grounded in our independently tested fire protection products and the standards that govern them. If your question isn’t here, contact us and our team will answer it directly.

Common passive fire protection questions

Browse the topics below, covering the basics of passive fire protection, cavity barriers and cladding, testing and certification, specification support, and how we work. Each answer links through to the relevant product and technical detail.

What is passive fire protection (PFP)?

Passive fire protection (PFP) refers to built-in building components that contain or slow the spread of fire and smoke without requiring activation. Unlike active systems such as sprinklers or alarms, passive measures are always in place and form part of the building’s fabric. Examples include fire-resistant walls and floors, cavity barriers, fire stops, fire doors, and intumescent materials. PFP works by dividing a building into fire-resistant compartments, giving occupants time to evacuate and emergency services time to respond. It is a legal requirement under UK Building Regulations and is essential to any fire safety strategy.

Fire compartmentation is the practice of dividing a building into sealed sections using fire-resistant walls, floors, doors, and cavity barriers. Each compartment is designed to contain fire, smoke, and heat for a specified period, typically 30, 60, or 120 minutes. This containment protects escape routes, limits property damage, and gives firefighters greater control. Compartmentation is a core requirement of Building Regulations Approved Document B and applies to residential, commercial, and public buildings. Cavity barriers play a critical role by sealing concealed voids where fire could otherwise spread unseen between compartments.

Tenmat specialises in the development and manufacture of advanced passive fire protection materials, with over 100 years of engineering expertise. Unlike many competitors, we produce our own unique intumescent technologies in-house at our Manchester facility, giving us full control over quality and innovation. Our product range includes open-state / ventilated and closed state / unventilated cavity fire barriers, intumescent pipe fire sleeves and oversleeves, socket box inserts and covers for electrical penetrations, fire and acoustic downlight covers, fire-rated ceiling air valves and vent duct fire sleeves, linear gap seals, and Firefly intumescent materials for OEM applications. All products are independently fire tested.

Tenmat cavity fire barriers support a wide range of external cladding and facade applications. Our product range covers rainscreen cladding, brick slip systems, timber frame construction, masonry cavity walls, and weatherboard facades. Products include the FF102/50 intumescent strip cavity barrier, VFB cavity barriers for open-state / ventilated applications and the NVFB range for closed-state / non-ventilated applications, and dedicated brick slip cavity barrier systems. Each product is fire tested for specific construction types and cavity sizes, helping specifiers meet the requirements of Building Regulations Approved Document B. Contact our technical team for project-specific guidance on the right barrier for your facade system.

A cavity barrier is a fire protection component installed within concealed spaces in a building, such as wall cavities, roof voids, and behind cladding, to prevent fire from spreading through these hidden pathways. In the event of a fire, intumescent cavity barriers expand to seal the gap. Under Building Regulations Approved Document B, cavity barriers are required at junctions with compartment walls and floor and around openings. They are essential in rainscreen cladding, timber frame, masonry, and brick slip facades. See our comprehensive guide to cavity barriers for full details.

Yes. All Tenmat products are independently fire tested by accredited third-party laboratories and hold relevant certifications. Key standards include BS EN 1363-1 (general fire resistance testing), BS EN 1366-4 (linear joint seals and cavity barriers), and ASFP TGD19 (open-state cavity barrier testing). Relevant products are classified under EN 13501-2 for fire resistance performance and many carry IFC third-party certification. Our testing covers a wide range of construction types and substrates to more closely replicate project details or site conditions. Tenmat products are designed to meet the requirements of Building Regulations Approved Document B, with fire resistance ratings of up to 120 minutes. All test reports, certificates, and data sheets are accessible through contacting our Technical Hub.

When specifying passive fire protection, look for products with independent third-party testing and certification, not just manufacturer claims. Key certifications include IFC Certification (issued by IFC Certification Ltd, part of KIWA) and UL-EU (issued by Underwriter’s Laboratories (UL)), which verify that products have been tested and then assessed by an independent body. Also look for test evidence against relevant standards such as BS EN 1366-4, BS EN 1363-1, and ASFP TGD19. CCPI (Code for Construction Product Information) assessed status provides further assurance that published product data is accurate and verified. Tenmat products carry IFC and UL-EU certification supported by extensive fire test data across multiple construction types.

Tenmat provides hands-on technical support at every stage of a project, from early design through to installation. Our IFE Level 3 qualified technical team and regional specification managers can advise on product selection for specific construction types, cavity sizes, and fire rating requirements, helping you meet Building Regulations with confidence. For quick self-service, our online Product Selector lets you filter by performance criteria to find suitable solutions. For complex or non-standard projects, we offer direct consultations to ensure the correct products are specified. Get in touch with our technical and specification teams to discuss your project.

Tenmat offers a RIBA-approved CPD on passive fire protection, covering cavity barrier technology, intumescent material performance, fire testing standards, and regulatory requirements. The one-hour technical discussion is suitable for architects, specifiers, contractors, and anyone involved in the design or construction of external facades. Sessions are delivered by our National Specification & Supply Chain Manager and can be arranged in-person or virtually for individuals or full teams. We also provide practical product guidance for site teams during installation. Book a CPD session for your team to fulfil your professional development requirements.

All Tenmat technical & product documentation is available through our Technical Hub. This includes product data sheets with installation guidance. Documentation is organised by product category – cavity barriers, electrical service penetrations, ventilation, lighting, mechanical service penetrations, and millboard for quick access. Individual product pages also contain downloadable resources specific to that product. If you require additional documentation, such as project-specific test evidence or application guidance, our technical team can assist directly.

Tenmat’s primary market is the construction sector, where our passive fire protection products are used in façades, walls, and for service penetrations across residential, commercial, high-rise, healthcare, education, and modular buildings. We also serve marine and shipbuilding, manufacturing, and supply high-temperature and intumescent materials for safety-critical applications.

Tenmat products provide reliable passive fire protection that slows the spread of fire and smoke in buildings. Our materials are engineered for high performance, regulatory compliance, and long service life. As a vertically integrated manufacturer, Tenmat develops and produces its own intumescent materials in-house, giving us direct control over quality, consistency, and innovation. Many of our solutions also deliver thermal and acoustic insulation benefits. Products are designed for efficient installation and are independently fire tested. Our advanced low-smoke, zero-halogen technologies support safer and more sustainable building design.

Tenmat is committed to responsible manufacturing and sustainable product design. Our intumescent materials use low-smoke, zero-halogen formulations, reducing toxic emissions in a fire event and supporting safer building environments. As a UK-based manufacturer, we maintain short supply chains and direct control over production processes. Tenmat products are designed for long service life and consistent performance, reducing the need for replacement. We are actively working to develop Environmental Product Declarations (EPDs) across our range to support specifiers with transparent lifecycle data. For current sustainability information, contact our team.

Still need an answer?

Our technical team supports projects from specification through to installation, advising on product selection for specific construction types, cavity sizes and fire ratings. Send us your question or project detail below and we’ll come back to you with a clear recommendation.