Suspended ceiling types W, X, Y, Z - Material and classification requirements

Ceiling type Description W Surface of ceiling exposed to the cavity should be Class 0 or Class 1 (National Class) or Class C-s3,d2 or higher (European Class). X Surface of ceiling exposed to the cavity should be Class 0 (National Class) or Class B-s3,d2 or higher (European Class). Y Surface of ceiling exposed to the cavity should be Class 0 (National Class) or Class B-s3,d2 or higher (European Class). Ceiling should not contain easily openable access panels. Z Ceiling should be of a material of limited combustibility and not contain easily openable access panels. Any insulation above the ceiling should be of a material of limited combustibility.