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Fire resistance

Reasons why gypsum is strong against fire
Gypsum is strong against fire. The secret is in crystallized water equivalent to about 21% of its weight.

This crystallized water is very stable in normal condition and does not disperse, but once it comes in contact with the heat of fire it will cause thermal decomposition and start to evaporate. The temperature of gypsum does not rise above a certain temperature until all of the crystallized water evaporates into water vapor and is released. To put it in simple words, imagine the same phenomenon that when you blow a flame with a burner onto a lump of ice, that part gradually dissolves into water and the ice temperature is kept below 0C until all the ice melts.

Fire resistance regulations in the Building Standards Act
  • The fire resistance requirement for each part of fire resistant building is prescribed in Article 107 of the Building Standards Act Enforcement Ordinance.
  • Fire resistance requirement is classified into damage resistance, thermal insulation, and flame retardancy, and fire-resistant time is specified for each part.
  • According to the Building Standard Act, it regulates that fire partition compartments should be provided to prevent the spread of fire and the transmission of smoke.
    It also regulates that columns and beams should be encased with fire resistant materials to prevent collapse of building due to fire.

Technical standard on fire resistance performance
Structural part Fire resistant structure (Article 2 clause 7 of the Act)
Floors where the number of floors counted from the top floor is more than 2 and less than 4, including the top floor itself
(Article 107 of the Ordinance)
Floors where the number of floors counted from the top floor is more than 5 and less than 14
(Article 107 of the Ordinance)
Where the number of floors counted from the top floor is more than 15
(Article 107 of the Ordinance)
Partition Walls (Non-loadbearing wall) 1 hour 1 hour 1 hour
(Limited to shear wall) 1 hour 2 hour 2 hour
Outer wall Shear walls 1 hour 2 hour 2 hour
Parts where there are risk of fire spreading 1 hour 1 hour 1 hour
Parts other than the above 30 minutes 30 minutes 30 minutes
Column 1 hour 2 hour 3 hour
Floor 1 hour 2 hour 2 hour
Beam 1 hour 2 hour 3 hour
Roof 30 minutes
Staircase 30 minutes
Related designated structure Ministry of Construction Public Notice No. 1399 Year 200
* gMinistry of Constructionh is the former name of the current gMinistry of Land, Infrastructure, Transport and Tourism (MLIT)h

Fire partition
A section to prevent fire from spreading and to secure an evacuation route. (Building Standard Act Enforcement Ordinance, Article 112)
Regarding certification of fire resistance by the Minister of Land, Infrastructure, Transport and Tourism
Fire resistance of walls, floors, ceilings, pillars, etc. is certified by performing fire resistance tests at a public laboratory and satisfying certain criteria (fire resistance requirements).

Classification of fire resistance performance requirements
Damage resistance Performance that does not cause deformation, melting, destruction or other damage
Heat insulation Performance to prevent the temperature on the non-heated side rising above the ignition temperature of combustible matter
Flame retardancy Prevents occurrence of cracks or other damage that will cause the fire to spread from the indoor side to the outdoors
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