Fire resistance tests refer to testing of systems designed to contain or resist fire over a specified period of time. They are very different to reaction to fire tests but are sometimes confused. Fire resistance classifications are often expressed as a period of time such as ‘1 hour fire resistance’ or three numbers such as 60/60/60. It is important to understand what each classification means.When it comes to fire resistance, which is usually expressed in the form xx/yy/zz, the key elements to consider are structural adequacy (xx), integrity (yy), and insulation (zz).
For external wall systems, fire resistance criteria depends largely on application and proximity to the building boundary, and proximity to other buildings. These are an integral part of the NZBC. In general more demanding applications and closer proximity to boundaries or other buildings requires higher levels of fire resistance.