Surface Finishes

The surface finishes, as specified in the drawings shall be one of the followings:

a) Anodised Finished (Natural/Black)

Where described as anodised extruded aluminium, the anodic coating shall be minimum 15 microns, or such other minimum thickness as shown in S.O’s drawing.

Where described as anodised aluminium, the aluminium shall be finished by either be:

(i) anodic coating to 15 microns minimum complying with BS 3987.

(ii) combined coating to comply with BS 4842 with minimum 9 microns anodic coat and 7 microns for the liquid organic coat. All surface treatments shall be applied by an approved specialist factory and shall conform to the requirements of BS 1615:1972 or as amended or the relevant S.S. code. The Contractor shall submit samples of the finished aluminium and submit details of the anodising process in the schedule of Technical information.

b) Polyester Powder Coat Finished

Unless otherwise specified, the surface finishing for all the aluminium works shall comply with the requirements of BS 4842 or the relevant S.S. codes.

The polyester powder coating shall be applied by an approved specialist factory to a minimum thickness of 70 microns or such other minimum thickness as shown in the S.O's drawings and shall be in a colour approved by the S.O.

The Contractor shall submit samples of the finished aluminium and submit details of this powder coating process in the Schedule of Technical information.

17.9 Installation

a)

Generally

Doors, windows, etc., shall be set in their correct location, as shown in the Drawings, and shall be level, plumb and square, at their proper elevation and in alignment with all works and fixed within the tolerance permissible for aluminium works, all to the satisfaction of the S.O. Joints at heads, cills and jambs between metal and masonry or concrete shall be grouted with cement and sand filling of thickness not greater than 20mm and shall be fully caulked all round and pointed with an approved waterproof mastic. The waterproof admixture when installation work is completed to be used shall be of a brand approved by the S.O.

Frames shall be set and fixed to walls with lugs. No screw fixing through the aluminium frame will be allowed.

b) Doors and Windows

All doors and windows shall be fixed strictly to the manufacturer's instruction and must be fully watertight. All joints shall be sealed with an approved waterproof mastic and finished to a neat flush joint with the window door frame.

The operating devices, mechanisms and ironmongery shall be installed so that they will operate smoothly and freely, without excessive friction, noiselessly and shall be adequate for the purpose of which they are intended.

Doors, casement and top hung window sashes shall be hung on aluminium butt hinges. Lockset shall be approved by the Architect and shall be supplied with push/pull handles.

In sliding units, adjacent aluminium members shall not slide upon each other but shall be separated by a material that does not react with aluminium and does not interfere unduly with the sliding.

All sliding sashes shall be supported on bearing devices that facilitate the movement and prevent direct contact between the sashes and the aluminium tracks.

The design of louvered panels shall prevent any back flow of rainwater into the interior of the buildings under any conditions.

Swing doors shall be hung on approved single or double action floor springs. Locksets shall be approved by the S.O and shall be supplied with push/pull handles.

In two leaf doors, one leaf shall be in addition fitted with two concealed bolts.

Glazing to doors shall be from the inside, secured by aluminium beads fitted into the extruded frames, having PVC glazing gaskets and/or approved sealant.

c) Fixed Panels

Glazing to fixed panels shall be from outside, secured by aluminium beads fitted into the extruded frame having PVC glazing gaskets and/or approved sealant.

d) Dissimilar Materials

Where treated aluminium surfaces, may come in contact with concrete, plaster, steel or other dissimilar metal or material, with other metals, water absorbent or porous materials, or incompatible materials, the aluminium surfaces shall be kept from direct contact with these materials with one coat of approved anti-corrosive and anti-bimetal chemical reaction paint applied before fixing.

e) Protection before and after installation

All aluminium sections shall not be stored in a manner where they rub or slide against each other or against other metallic surfaces.

All components where possible shall be delivered to the Site in individual plastic wrapping, stout papers, cardboard or other protective covering which shall not be allowed to get damp.

The Contractor shall provide cover on all exposed aluminium surfaces, etc., during transportation and installation against damage by contaminated moisture, staining, abrasion, wet cement, wet plaster and other injuries, including provision of proper storage sheds for materials delivered to site.

Any aluminium unit which is damaged in any way during transportation, before or after installation shall be replaced by the Contractor at his expense.

f) Application

All finishing treatment of aluminium surfaces shall be carried out by an approved licensed applicator in strict conformity with the specifications for cleaning, priming and finish coat applications and quality control. The Contractor shall submit the specification for the proposed anodising and/or coating to the aluminium works.

All aluminium surfaces shall be free from scratches, blemishes and/or any defects that will affect the appearance and/or performance and shall be thoroughly cleaned and etched before pre-treatment.

The Contractor shall keep proper records of the entire anodising and/or coating production. The records shall be submitted by the Contractor to the S.O upon request.

g) Colour Match Tonality and Texture

All surface finish of the same stipulated colour must have the same tonality throughout.

The completed work shall present an uniform appearance in regard to colour and texture and shall be a satisfactory match with identical samples of colour patches held by the S.O.

h) Workmanship (i) Fabrication

The Contractor shall be responsible for checking the dimensions of all opening sizes on site prior to fabrication of the aluminium sections.

Aluminium members shall be fabricated to the best standard of workmanship under experienced factory supervision and control.

Joints in frames, at corners, junctions or intersections, are to be welded and so assembled to be as strong and rigid as adjoining sections. Welded joints shall be permanently watertight.

Permissible tolerance shall be provided for expansion and contraction in members exposed to weather. Any distortion in the aluminium members or any glass cracked or broken due to inadequate provision for tolerance must be replaced and made good by the Contractor at his expense.

Components shall be delivered, stored and handled to prevent damage of whatever nature, factory-finished metals shall be protected in an approved manner (e.g. removable PVC sheeting/lining) during transportation and installation and such protection shall be removed when directed.

(ii) Modifications

The Contractor may make minor changes in construction details of the units in order to facilitate erection on site, such changes shall not be made without prior approval by the S.O in writing.

No extra cost shall be payable to the Contractor in respect of these changes.

(iii) Tolerances

The limits of sizes for the overall length and overall height shall be stated by the Contractor taking into account permissible deviations in size and squareness.

The tolerance for windows on overall dimensions shall not be greater than +/-1.5mm.

The tolerances for the location of centre lines of mullions and transoms etc. shall be +/-1.5mm except where transoms or mullions form part of a continuous strip where the tolerance shall not be greater than +/-0.4mm.