PLASTERING WORK

1.0 OBJECTIVE

1.1  To define the requirements and procedure for plastering works for the contract no GTC.101/ED/01 Engineering, Procurement, Installation and Commissioning (EPIC) of Ras Laffan Utilization Project –Buildings and utilities and support service Phase 1-Utilities.

2.0 SCOPE

2.1 Applicable to all the buildings and utilities at Service Base Area, Service Berth Area, FSO Marine and Telecom buildings.

3.0 REFERENCE

3.1  Project Approved Drawings

• Qatar Petroleum standard Spec. Vol. 1, section 9.34.2, 9.34.3 and 9.34.5, 9.36
  • British Standard BS 812, BS 12 &  BS 4027

4.0 PROCEDURE

4.1 MATERIAL REQUIREMENT:

• Material approval for Sand, cement and water has to be obtained from QP prior to take up the plastering work.

• Cement shall be of Portland cement  conforming to BS 12, SRC shall comply with BS 4027.

• Sand for mortar shall be of beach or dune sand washed clean free from clay, chalk, shells organic materials and other impurities. The sand shall comply with BS 1200.

• Water shall be potable.

4.2 RENDERING:

• Mortar mix shall be accurately gauged by volume using approved gauge boxes.

• The ingredients shall first be mixed dry thoroughly to obtain a uniform color before water is added to the mix.

• Rendering shall be composed of one part cement to three parts sand by volume.

• Only sufficient material shall be prepared  which can easily be applied within the initial setting time of the material and no water shall be added after the initial mix. Unset plaster shall be discarded when initial set occurs and no reconstituted mix shall be allowed.

• Surfaces to receive plasterwork shall be brushed down to remove dust loose flecking material shall be removed and the projections of mortar and the like shall be clipped off or ground away. Surfaces shall be dampened sufficiently to ensure uniform absorption.

• Backgrounds shall be prepared as required to suit the finish being applied. Dense, smooth concrete shall be keyed with PVA emulsion bonding agent, blockwork shall be hacked if necessary.

• Junctions between dissimilar materials such as blockwork and concrete shall be covered with a continuous strip of galvanized expended metal lathing at least 300 mm wide securely nailed in position with plated masonry mails.

• Metal angle beads, casing beads and the like shall be fixed in placed before commencing plastering and the plastering shall be worked up to the bead to finish flush.

• Rendering to finish 12 mm thick may be carried out in one coat. Rendering over 12 mm thick shall be carried out in two coats. In two coats of works the coats shall be of equal thickness, the first coat shall be properly scratched and keyed for the second coat.

• The finished surface of the rendering shall be smooth with a wood float.

• Rendering shall be prevented from drying out too quickly. All external rendering shall be protected by properly constructed hessain or similar  screens during hot period.

• The surface of the finish coat shall be smooth and free from waviness irregularities or blemishes with straight level and plumb angles.

• Curing shall be done with approved potable water for a period not less than 7 days in any case.

5.0 Records :

• Material approval for cement, sand and water.

• Inspection reports.

• Checklist.