Reference
Hot works & fire matting glossary
Plain-English definitions of the fire-classification, hot-work and material terms used across this site. Where a term is a standard, we link the source. We don’t use “fireproof” — no matting is.
Fire classification & test standards
How a floor covering’s reaction to fire is measured and described in the UK and Europe.
- EN 13501-1
- The European/British standard that classifies the reaction to fire of construction products. For floor coverings it uses a dedicated scale with the “fl” subscript and a separate smoke sub-class. Source: measurlabs.com
- Flooring classes (A1fl–Ffl)
- The reaction-to-fire ladder for floorings: A1fl (best, effectively non-combustible) through Bfl, Cfl, Dfl, Efl to Ffl (no performance determined). A mat lower on the ladder ignites or spreads flame more readily. Source: measurlabs.com
- s1 / s2 smoke
- The smoke-production sub-class added to a flooring class; s1 is less smoke, s2 is more. Floorings only use s1 or s2 — there is no s3 for floorings. Source: measurlabs.com
- Bfl-s1
- A higher flooring reaction-to-fire class with low smoke. Some modular hot-work tiles (e.g. Workwell Link-Fire) state this class. Always confirm it on a named product’s test certificate. Source: workwellmats.co.uk
- Cfl-s1
- A common flooring class for popular anti-fatigue welding mats (e.g. COBA Diamond Tread). It is a step below Bfl-s1, which matters where a higher class is specified for hot work. Source: coba.com
- EN ISO 9239-1
- The radiant-panel test for floorings that measures flame spread, smoke and the critical heat flux — one of the two tests behind the Bfl/Cfl/Dfl classes. Source: ri.se
- EN ISO 11925-2
- The single-flame ignitability test applied to construction products; for floorings it is required alongside EN ISO 9239-1 for the higher classes. Source: measurlabs.com
- ISO 9150
- A method that counts how many molten-metal drops a material withstands before a set temperature rise. It is a clothing/material test — a drop count, not a temperature rating, and not a flooring standard. Source: iso.org
- EN ISO 11611
- The standard for protective clothing used in welding. It is PPE, so a floor mat does not “carry” it — useful for context, not as a mat specification. Source: iso.org
Hot work, hazards & site terms
The work, the by-products and the controls around welding, grinding and cutting.
- Hot work
- Any task that produces heat, sparks or flame — welding, grinding, cutting, brazing and similar. It usually requires a permit, controls and a fire watch.
- Fire watch
- A person who monitors the area during and after hot work to catch smouldering fires. Required durations vary by scheme; in the US OSHA requires at least 30 minutes after work, and NFPA 51B (current edition) requires at least 1 hour. Source: osha.gov
- Exclusion / clearance zone
- The area around hot work kept clear of combustibles or protected. US guidance (NFPA 51B / OSHA) uses 35 ft (10.7 m); UK practice (HSE HSG168 / FPA RC7) typically clears or protects to about 10 m, set by the risk assessment. Source: hse.gov.uk HSG168
- Spark
- A small, hot, fast-moving particle thrown from welding, grinding or cutting that can ignite combustibles or pit a floor.
- Spatter
- Droplets of molten metal flung from the weld pool that land nearby and can fuse to, burn or stain a floor.
- Slag
- The crust of solidified flux and oxides that forms over a weld or cut; hot slag falling to the floor is a common ignition and damage source.
- Dross
- Molten and re-solidified metal expelled during thermal and plasma cutting, often thrown further than arc-welding spatter.
- Swarf
- Metal chips, filings and abrasive dust produced by grinding and machining; abrasive underfoot and a slip and housekeeping hazard.
Material & fire behaviour terms
The words used (and misused) to describe how a mat reacts to heat and flame.
- Fire-resistant
- Able to resist ignition and limit fire damage for its rated use. The honest term for hot-work floor matting — it withstands exposure, it is not immune to fire.
- Flame-retardant
- Treated or built to resist catching alight and to slow flame spread. Describes material behaviour, not a guarantee against all heat sources.
- Self-extinguishing
- Stops burning once the flame source is removed. Accurate only where a product is tested to behave this way.
- Fireproof
- A term we avoid. It implies a material cannot burn or be harmed by fire, which is not true of any matting. We say fire-resistant, flame-retardant or self-extinguishing instead.
A class or temperature only means something on a specific product. Always request the named product’s test certificate or datasheet. Seefire classification for flooringandwhat fire rating welding mats should have.
Enquiries
Tell us about your hot work area.
Welding bay, grinding station, fabrication cell or temporary site hot work — send the process, area size and any oil, coolant or fire-classification requirement. We’ll help specify spark-resistant floor protection.