Abstract: Asbestos sheets are delivered from a forming machine to a stacking station at which the sheets are interleaved with flat or corrugated patterns before passing on to a seasoning store. The sheets and the patterns are carried on respective trolleys which move along guideways and through a transfer mechanism to a stack forming station. An auxiliary guideway is mounted above the guideway for the trolleys which carry the mixed stack, this auxiliary guideway being disengageable from the trolleys, for example by separating the auxiliary guideway rails, to allow an elevator at the stacking station to lower the stack carrying trolley to floor level, the auxiliary guideway then being reformed to receive a further trolley upon which a stack is formed while the first stack-carrying trolley is removed at floor level, so that stacking of the sheets can take place uninterruptedly.