SPECIFICATION AND STANDARD FOR STRUCTURAL STEELWORK: GENERAL PART 9 - SURFACE PREPARATION

1.15.1       General

1.15.1.1    All steel surfaces to be painted including welds and connections shall be thoroughly cleaned to remove all dirt, grease and other contaminants.  They shall at no stage have rusted beyond the allowable levels as specified in Swedish Standard SIS 05

5900.    All  rust  and  loose  scales  shall  be  completely  removed  by  mechanical cleaning,  blast  cleaning,  wire  brushing  and any other  approved  method.    After

surface preparation, the surface roughness is to be compatible with the coating to be applied but nowhere exceeding a peak-to-trough amplitude of 80 micrometres. Application of coating, paint and bitumen, etc. shall be carried out as soon as the

surface preparation has been completed.

1.15.2       Mechanical Cleaning

1.15.2.1    Mechanical cleaning, if applicable, shall be carried out by power driven tools, such as carborundum grinding discs and chipping hammers, followed by steel brushing and dusting to remove all loosened materials.

1.15.2.2    Excessive burnishing of the steel through prolonged application of rotary wire brush shall be avoided.

1.15.3       Blast Cleaning

1.15.3.1    Blast cleaning, if applicable, shall be carried out in accordance with BS 7079.  The maximum grade of abrasive permitted is specified in BS 7079.

1.15.3.2    Non-metallic abrasive used for blasting shall be free from harmful contamination and recovered material shall only be reused subject to the approval of SCI.

1.15.3.3    Blasted surfaces shall be brushed or cleaned by vacuum and shall not be touched by hand or contaminated in any other way.

SPECIFICATION AND STANDARD FOR STRUCTURAL STEELWORK: GENERAL PART 9 - CORROSION PROTECTION

1.14.1       General

1.14.1.1    All structural steelwork, including welds and connections shall be protected against corrosion in the manner specified in BS EN ISO 14713 and where applicable BS

7361.

1.14.1.2   Other methods of corrosion protection may include metallic coating, painting, bituminous coating, cathodic protection, vermiculite  coating, etc. The Contractor shall provide equipment for measuring the thickness of coating when instructed by SCI.  The cost of the equipment is deemed to have been included in the Contract Price.

1.14.2       Temporary Protective Systems / Prefabrication Coatings

1.14.2.1    The Contractor shall provide at his own cost, any temporary protective system or prefabrication coating required during transportation and storage, and shall remove such system at his own cost.

1.14.2.2    The system shall be applied at the Contractor’s discretion and shall be additional to the main protective system. If a prefabrication coating is applied, the Contractor shall provide evidence to demonstrate that it is fully compatible with the main protective system or sprayed fire protection, where applicable.

1.14.3       Manufacturer’s Instructions

1.14.3.1    The  Contractor  shall  obtain  from  the  manufacturer  of  any  proprietary  product detailed instructions on the use of the product, specific to the situation found in the Contract.

1.14.3.2    The manufacturer’s instructions shall be complied with for the use of any product.

The Contractor shall notify the Engineer of any conflict with the requirements of this section of the Specifications, before the commencement of work.

1.14.4       Use of Red Lead Primer

1.14.4.1    Painting using red lead primer shall be deemed to be the method of corrosion protection if no other method is specified.

1.14.4.2    Surface preparation shall be by means of mechanical cleaning and no blast cleaning will be required unless otherwise specified.

1.14.4.3    The Contractor shall apply a minimum of two primer coats to the steelwork, one of which shall be applied after surface preparation is completed and approved by SCI. The second coat shall be applied only before erection. The primer coat shall be applied at a rate of not more than 13m2/litre of paint.

1.14.4.4    The dry film thickness shall be as recommended by the paint manufacturer and approved by SCI. The Contractor shall provide equipment for measuring the thickness of coating.

1.14.4.5    No painting shall be needed at the steel bearing surfaces when high strength friction bolts are used.

1.14.4.6    Any paint areas, which have been damaged or deteriorated during transportation or storage, shall be properly repaired and touched up, at the Contractor’s own cost.

1.14.5       Structural Steel Encased in Concrete

1.14.5.1    Unless otherwise specified, steel surfaces to be encased in concrete shall be left unpainted and shall be cleaned and free from loose rust and scale at the time of

concreting.

1.14.6       Bituminous Coating

1.14.6.1    Bituminous coating, when specified, may include bitumen and coal tar pitch and shall be applied in accordance with BS 1070, BS 3416, BS 4147 and BS 4164.

1.14.7       Cathodic Protection

1.14.7.1    Cathodic  protection,  when  specified,  shall  be  carried  out  in  accordance  with

BS7361.

1.14.7.2    Upon completion of the cathodic protection works, the Contractor and specialist sub- contractor shall jointly furnish the warranty as specified by SCI, against product failure.

1.14.8       Hot-dip Galvanising

1.14.8.1    Hot-dip galvanising of structural steelwork, where specified, shall be zinc coating in accordance  with  BS  EN  ISO  1461.  Minimum  coating  thickness  shall  be  in accordance to that specified in BS EN ISO 1461, in relation to the articles and its thickness.