Traffic & Fire Protection

Fire protection is not optional — it is a life safety requirement. Whether insulating structural steel, compartment walls, ventilation ducts, or cable trays, the insulation material must deliver proven fire resistance, prevent flame spread, and maintain structural integrity under fire conditions for the rated period.

Rosetexwool rock wool and ceramic fiber solutions offer Class A1 non-combustible fire performance with melting points above 1000°C. Our products are tested to international fire resistance standards including BS 476, EN 1366, ASTM E119, and EN 13381, providing reliable passive fire protection for buildings, tunnels, and industrial facilities.

Selecting fire-protection insulation for buildings, transport infrastructure and vehicles means balancing fire rating, service temperature and weight. How rock wool compares with the materials used across traffic and fire-protection projects:

For most traffic and fire-protection assemblies rock wool delivers the best balance: A1 non-combustible, mechanically strong and cost-effective, while ceramic fiber handles extreme temperatures in tunnel and furnace zones.

Typical Traffic & Fire Protection Application Scenarios

Across buildings, transport infrastructure, vehicles and marine structures, rock wool, ceramic fiber and calcium silicate deliver certified fire safety and thermal control:

• Curtain-wall fire stopping — rock wool slabs fill the cavity between floor slabs and the facade, forming a fire and smoke barrier at every floor line (tested to EN 1364 / ASTM E2307).
• External wall insulation fire barriers — non-combustible rock wool break strips interrupt combustible EIFS layers on high-rise facades.
• Tunnel lining & escape-route protection — ceramic fiber and rock wool boards line tunnel crowns and evacuation corridors, protecting escape paths.
• Marine fire divisions & A-60 bulkheads — rock wool is the standard SOLAS-compliant material for A-60 class bulkheads and decks; calcium silicate boards (100% asbestos-free, salt-spray resistant) are widely used for ship fire-division walls and LPG-tank fire barriers.
• Ship exhaust & power-system insulation — ceramic fiber jackets insulate marine exhaust uptakes and boiler piping to 1200°C, cutting heat radiation in engine rooms.
• EV battery-pack thermal runaway protection — rock wool fire layers and calcium-silicate nano super-insulation boards sit between cells and modules. The nano board meets UL 2580, withstanding 2000°C+ transient shock and giving 2-hour no-ignition protection at ~0.03 W/(m·K).
• Turbocharger & exhaust heat shields — ceramic fiber shields wrap turbochargers and heavy-machinery exhausts (to 1200°C), improving safety and under-hood efficiency.
• Energy-storage system safety — calcium-silicate boards block thermal propagation from a failing battery cell to other units in storage cabinets.
• Rail & rolling-stock interiors — rock wool and glass wool meet EN 45545 fire-safety requirements for train ceilings, walls and underfloor insulation.
• Steel-structure fireproof encapsulation — rock wool boards clad exposed steel beams and columns, preserving load capacity during a fire.

Material choice follows the hazard: for facade and compartment fire stopping rock wool is preferred for its rigidity and A1 rating; for high-temperature tunnel, exhaust and turbocharger zones ceramic fiber is specified (to 1200°C); in humid, salt-spray marine areas calcium silicate adds moisture and corrosion stability, and its nano super-insulation board is the go-to for EV-battery and energy-storage fire safety. Rosetexwool supplies cut-to-size boards, slabs, blankets and jackets with the required fire-certificate documentation for each project.

Related Articles

• Rock Wool Applications in Construction
• Rock Wool External Wall Insulation Installation
• Rock Wool Marine & Offshore Applications

Fire-safe transport and infrastructure require certified non-combustible insulation. Related safety and building applications:

• Building insulation for fire-rated building assemblies
• Green building insulation for safe, acoustic, and fire-resilient design
• Marine and offshore insulation for marine and offshore fire protection
• Pipe insulation for fire-rated pipe enclosures

Tunnel Lining & Traffic Infrastructure Fire Performance

Tunnel fires are among the most punishing thermal events an insulation system can face. A design fire of tens of megawatts develops inside a confined bore, the concrete lining is spalled by rapid thermal shock, and the steel reinforcement in the crown loses strength within minutes. In a tunnel, insulation is not a comfort or efficiency item — it is what keeps the structure standing and the escape route passable long enough for people to get out.

Concrete linings are already non-combustible, so the question is not flame spread but thermal protection of the structure and of the services running alongside it. Three material families cover that duty inside one bore:

• Crown and high-heat zones — ceramic fiber board and blanket, rated for continuous service far above any fire-time gas temperature, used as the hot-face layer behind a protective facing.
• Escape galleries, cross-passages and cable ducts — rock wool board at 100–180 kg/m³, A1 non-combustible under EN 13501-1, holding geometry and thermal performance through repeated wet/dry cycling and traffic vibration.
• Wet or seeping sections — calcium silicate board, dimensionally stable where water runs down the bore instead of being absorbed and degrading the layer.

Fixing matters as much as material choice. Tunnel boards are anchored to the concrete with welded pins or drive-in anchors carrying washers, fitted with compression so the board stays in contact under traffic vibration and any pressure wave. Board joints are closed, and the layer is protected against water ingress before the final rendering, paint or facing is applied.

Where the bore carries hazardous-goods traffic or sits close to petrochemical plant, the design fire follows the hydrocarbon (HC) heating curve rather than the standard building curve — a far higher peak and rate of rise. Size the hot-face layer for that curve. Do not size it from a standard fire test and assume the margin holds.

Every tunnel package ships with EN 13501-1 classification reports, non-combustibility test data and fixing details for the lining profile you supply. For the background behind A1 ratings and non-combustible systems, see non-combustible insulation systems and A1 fire ratings.

From Fire Rating to Millimetres: Sizing Passive Fire Protection

Every steel fire-protection job starts with the same question, and the honest answer is more nuanced than a rule of thumb: how thick does the board have to be? For fibre boards such as rock wool and ceramic fiber the governing behaviour is thermally thick — once the layer is deep enough that its cold face no longer reaches thermal equilibrium during the test period, the fire resistance rating depends far more on the section factor of the steel (heated perimeter divided by cross-sectional area) and on the critical steel temperature you design to than on the conductivity of the board.

That is why the industry sizes protection from the rating tables built on EN 13381-4, the fire test method for load-bearing steel sections, read together with the thermal guidance in EN 1993-1-2 (Eurocode 3, design of steel structures exposed to fire). Those tables give the required thickness for R30, R60, R90 and R120 for a given section factor and critical temperature. In practice: set the critical steel temperature from the fire design calculation, read the thickness from the table, add the fixing and compression allowance, then verify the assembly for the exact profile rather than trusting the generic row.

Indicative ranges our engineers work from, before section factor and critical temperature are applied:

Three details decide whether those numbers hold on site. First, fixing: pins must be long enough for the full compressed thickness, spacing is kept tight enough that no board bridges a void, and every pin carries a washer bearing on the board face. Second, joints and penetrations — a fire-rated wall or floor is only as good as the cables, ducts and conduits passing through it; those are closed with rated penetration seals and linear joint strips tested to the EN 1366 series, and the insulation is cut and fitted tight rather than left to fill a gap. Third, access for maintenance: valves, flange pairs and inspection hatches get removable panels built from rock wool board inside a wired mat, fastened with quick-release closures so the rating survives the tenth opening as well as the first.

Fire-rated assemblies also need a defined inspection path. Where the protection is buried in a ceiling, above a suspended grid or inside a cable duct, specify access panels at the intervals the maintenance plan requires — otherwise nobody learns that the board has settled until the next audit, or the next fire.

Related guides: fire rating comparison.