10.Effect of non-registration.- No employer of an establishment to which this Act applies shall,----(a) in the case of an establishment required to be registered under section 7, but which has not been registered under that section;(b) in the case of an establishment the registration in respect of which has been revoked under section 8 and no appeal has been preferred against such order of revocation under section 9 within the period prescribed for the preferring of such appeal or where an appeal has been so preferred, such appeal has been dismissed.Employ building workers in the establishment after the expiry of the period referred to in clause (a) or clause (b) of sub-section (1) of section 7, or after the revocation of registration under section 8 or after the expiry of the period for preferring an appeal under section 9 or after the dismissal of the appeal, as the case may be.