Thanks to the thermal properties and poor burning of cork, cork oaks are more fire resistant than other trees. The slow burning of cork makes it a natural flame retardant, creating a fire barrier. Its combustion does not emit smoke or toxic gases.
Cork, like other insulation products, is subject to fire classification. Fire classification has two basic functions:
- allows you to embed the given materials into the facility by confirming their fire properties,
is the starting point for the selection of security
Fire classifications are issued by the relevant research units for manufacturers of systems or products. An important part of each classification is the description of the solution to which it applies and the scope of its application (validity).
The fire resistance classes of a structure, here a wooden structure, indicate the ability to perform specific functions during a fire. The fire resistance parameter is marked with the letter “R” and numbers, e.g. 15 (this is the number of minutes after which the load-bearing elements cease to fulfill their function). Important parameters are also fire tightness “E” (flame and gas impermeability) and fire insulation “I” (temperature impermeability). On the basis of these parameters, the fire resistance class of the building is determined. Fire resistance is most often determined by the architect and firefighter on the basis of the law.
In cork studies, cork is assigned fire class E. Cork has a heat resistance of R-3.6 to R-4.2 per inch. This is a better value range than loose fiberglass (R-2.2 to R-2.9 per inch) and fiberglass mats (R-2.9 to R-3.8 per inch). Cork has a low thermal conductivity – cork is an ideal thermal insulator. Its thermal conductivity coefficient is 0.045W/mK. Due to its poor thermal conductivity, cork is always warm to the touch. The fire safety of cork is also supported by the fact that it is used in space shuttles due to its lightness, in a mixture with other materials for insulating e.g. fuel tanks in rockets or insulating landers.
In the video below you can see how hard it is to set fire to a cork.https://www.youtube.com/watch?v=YdSWJypDSbI