ISO 3729:1976

Fibre building boards — Determination of surface stability

Applies to hard and medium grades as defined in ISO 818. The method specified is similar to that described in ISO 3546: Measurement of the air escaping from a measuring head placed on the surface of a test piece conditioned in a specified atmosphere, repetition of the measurement after conditioning in a second specified atmosphere, and then again after reconditioning in the first specified atmosphere.