民用工程合同书(31)

　　provided always that a certificate of completion given in respect of any section or part of the permanent works before com - pletion of the whole shall not be deemed to certify completion of any ground or surfaces requiring reinstatement， unless such cer - tificate shall expressly so state.
27　guarantee against defects and liability for de- feetive work
　　in these conditions the expression "period of maintenance'shall mean a period of guarantee for one year from the date of completion of the works certifiecd by the employer in accordance with 26 hereof.
　　upon notification from the employer， the contractor shall rectify or reconstruct without delay， free of cost to the employ - er， any defects of damages arising out of faulty materials or workmanship.
　　if the contractor shall fail to do any such work as aforesaid required by the employer， the employer shall be entitled to em - ploy and pay other persons to carry out the same and if such work is work which， in his opinion， the contractor was liable to do at his own expense under the contract， then all expenses con- sequent thereon or incidental thereto shall be recoverable or which may become due to the contractor.
　　in the event the contract is terminated prior to completion of the work， the liability of the contractor for faulty material or defective workmanship shall apply to the partially completed work for a period of one year after the work has been fully com - pleted and taken over by the employer.
28　alterations， additions and ommissions
　　the employer shall make any variation of the form， quality or quantity of the works or any part thereof that may， in his opinion， be necessary and for that purpose， or if for any other reason it shall， in his opinion be desirable， he shall have power to order the contractor to do and the contractor shall do any of the following:
　　　　（a）increase or decrease the quantity of any work included in the contract
　　　　（b）omit any such work;