To supersede the requirements of Sentences 9.10.17.1.(1) and 9.10.21.1.(1), which would otherwise limit the flame-spread rating to 150, and require a lower limit over not less than 90% of the exposed surface area, on the basis that the corridors and walkways will be used as part of a means of egress and are thus required to have increased protection from the spread of fire.
To limit the probability that certain finishes having an inappropriately high flame-spread property will be used in the corridors and walkways of construction camps, which could lead to the spread of fire across the exposed surfaces of the finishes, which could lead to delays in the evacuation or movement of persons to a safe place, which could lead to harm to persons.