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 behavior 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 behavior, 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.
Quotes & specification help
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.