Construction Method
General
A schedule of work, where Shop Drawings, Material Purchase Order/Deliveries and Programmes for Installation are clearly shown, shall be prepared and submitted for review prior to commencement of work at site. The schedule of work can be prepared under three main following heading:
a) Preparatory Work
b) Installation on Site
c) Handover
The schedule of work shall also show the installation duration for every area separately including the necessary main power required on site. This schedule of work for Stone Cladding and Paving shall follow the dates and sequence of work mentioned in the schedule of work for the total project. Sufficient time for approval should be allowed for purchase orders and deliveries.
The subcontractor shall also plan and carry out Quality Control Scheme throughout the job, to ensure the quality of the finish product. It will be the subcontractor's responsibility to ensure that at every phase of the work:
a) Sufficient resources and material are available,
b) The quality of the material is not less than specified,
c) Slabs are installed securely and properly as stated in the specification.
It is also responsibility of the subcontractor to perform the final check on complete elevations, and release them for Handover. The subcontractor shall also adopt a Safety Plan in accordance with the General Requirements and Specifications. A safety officer should be appointed by the subcontractor to be present on site at all times to inspect the safety aspects regularly.
The subcontractor's Project Manager on site shall be fully responsible in implementation of the above, and shall employ the staff required to perform the work. The PM shall follow the Schedule of Work for Submittal, Purchase Order and Deliveries closely not to hinder the work on site. The PM shall also hold weekly co-ordination meetings with the Main Contractor's PM and prepare a report on the work progress.
Schedule of Work:
The subcontractor, prior to commencement of work, shall prepare a schedule of work for Cladding and Paving. The Schedule of Work for the project shall be studied thoroughly and the subcontractors' work schedule shall be prepared accordingly. The work schedule for structural, curtain walls and aluminium sub frames will be checked and the sequence of jobs for places where different trades meet will be defined clearly. The subcontractor shall co-ordinate with related trades for the design of connection details and shall submit the detailed drawings for approval. The Schedule of Work shall be composed under three main headings:
a) Preparatory Work,
b) Installation on Site,
c) Preliminary Handover.
Preparatory Work:
As Built Dimensions from site: As built dimensions from the site shall be measured and will be basis to shop drawings. Levels will be co-ordinated with the site management to mark the start and finish levels on the evaluations.The measurements will then be conveyed to design preparation of shop drawings.
Actual Site Conditions: A co-ordination meeting, with the PM will be held on site in order to be familiar with the actual site conditions to determine the locations of workshop, stockyard and warehouses.
Submittal for Approval:
a) Material Submittal: All stainless steel fixing systems and accessories will be subject to approval. The subcontractor shall prepare drawings and calculations for fixing systems according to general requirements and specifications. The biggest stone size and cavity are to be used as basis to calculations. Submittal shall include Material Specifications, manufactures, data, structural calculations and detailed drawings.
b) Shop Drawing Submittal: The subcontractor shall prepare shop drawings for cladding and paving work. The actual Architectural drawings shall be used as guidelines to shop drawings. Where possible, stone sizes will be standardised, so that the number of stone sizes are minimised. Upon approval of shop drawings cutting list shall be prepared for the manufacturer. The cutting list not to be submitted for approval since the subcontractor is fully responsible regarding dimensions and estimated wastage at site.
c) Mock-up on Site: During the approval stage of shop drawings, the subcontractor shall prepare a full mock-up on site. The location shall be co-ordinated with the PM. The fixing systems to be used for mock-up shall be the actual fixing systems for the job. Installation on Site The subcontractor shall prepare installation schedule for the work according to project schedule and will be followed up closely not to hinder the work on site. In general the following sequence of work shall be as following:
Datums and Grid Lines:
The main reference lines shall be provided by the Main Contractor. The subcontractor shall appoint and setting out engineer to tranfer and mark the lines at each floor. These setting out shall be checked during installation.
Plump Lines:
Plump Lines shall be provided for every corner and also where required, the PM shall be informed immediately.
Alignment:
Lines to check alignment will be provided for every row before installing. These lined shall be moved after the completion of the row and shall be relocated for the following row.
Installation:
Holes for Dowels shall not be drilled bigger than required to ensure proper fixation. The expansion bolts shall be tighten by torque spanners and sufficient torque shall be applied. The plump and alignment lines shall be fully observed.
Quality Control:
Upon completion of a row, the subcontractor's site supervisor and quality control officer together shall check the work and rectify any defects if any before continuing for consecutive row.
Cleaning and Remedial Work:
The completed elevation or floor shall be thoroughly cleaned and jointly inspected as described above, for any defects or remedial wok. The Subcontractors Quality Control Officer shall then release the elevation or floor for preliminary handover.
Preliminary Handover:
Upon completing an elevation or a floor the subcontractor shall move to a new area for installation. At this stage it is not practical for the subcontractor to follow up the protection measures for the completed elevation or floor. Hence elevation or floor is preliminarily handed over until final hand over. The main contractor shall take necessary steps to protect the elevation or floor as required by PM and leave the area protected to the satisfaction to the PM. The subcontractor shall not be responsible for any defects occurring afterwards unless these defects are related to installation but physical impacts by other trades, accidents and the likes. The preliminary hand over procedure shall be proposed by the subcontractor and submitted for review by Main Contractor. The competed areas will be cleaned thoroughly and inspected for defects. The Subcontractors Quality Control shall give the final release for the elevations or floors to be handed over. the representative for the Project Management will be invited to site and will be requested accept the preliminary handover of completed areas. Snag list shall be prepared at this stage, if any.