BS 4873:2009 pdf download – Aluminium alloy windows and doorsets – Specification
5.5 Fixings all straps, clips, brackets, lugs, and similar fixing devices and their attendant screws, bolts etc. shall be capable of meeting the applied wind and operational loads and shall achieve a minimum corrosion resistance of grade 3 (96 h) as specified in BS En 1670:2007.
NOTE 1 Screws, nuts, bolts, rivets, metal washers, shims and other fixings should be tested in the “as used” condition.
NOTE 2 Spacer shims used at fixings, which serve only as packing and do not influence the structural integrity of the fixing, may be of extruded or moulded plastics material.
NOTE 3 Austenitic stainless steel is the preferred material for fixings subject to external forces and corrosive influences.
5.6 Glazing materials Glass thickness and type shall be selected using the recommendations given in BS 6262‑1, BS 6262‑2, BS 6262‑3, BS 6262‑4 and/or BS 6262‑7, as appropriate, to withstand the design wind pressure calculated in accordance with BS 6375‑1 or BS 6399‑2. the exposed edges of glass adjustable louvre blades shall be arrised, ground or polished. insulating glass units shall conform to BS En 1279.
6 Construction and design NOTE The accessible parts of finished windows should as far as reasonably practicable be free from all sharp edges, burrs etc.
6.1 Work sizes the work sizes for overall length and height shall be documented.
6.2 Manufacturing tolerances the size of an assembled frame shall be within ±1.5 mm of the documented work size (6.1) in any dimension, and the difference between the diagonals of the assembled frame shall be not more than 4 mm.
6.3 Design for glazing the frame design shall be such that: the window can be glazed in accordance with BS 6262;
a) reglazing is possible without the need to remove the outer frame
b) from the structure of the building; it is possible to renew the weatherseals without removing the
c) outer frame from the structure of the building; it is possible to replace the hardware without removing the outer
d) frame from the structure of the building.
6.4 Openable windows and doors For windows and doors that are intended to be openable, the opening sashes or door leaves however designed shall move freely and smoothly without hindrance throughout their intended range of movement. in horizontally and vertically sliding windows and sliding doors, adjacent aluminium members shall not slide upon each other. in horizontally sliding windows and sliding doors, the sashes or door leaves shall be supported on bearing devices that facilitate movement and prevent direct contact between the sashes and the aluminium tracks. in vertically sliding windows, the mechanism or balancing device shall be accessible for adjustment, repair or replacement, after the windows have been installed.
6.5 Frame joints Joints in frames shall be made either by welding or by mechanical means (e.g. cleating, screwing and gluing) and shall have flush, stepped or lapped surfaces. For flush joints formed by mechanical means, any deviation from the same plane shall be within the limits set by the use of extrusion tolerances given in BS En 755‑9 or BS En 12020‑2.
NOTE The use of “L” shaped plates (chevrons) in mitred joints can help achieve the required finish, and the weather performance of metal‑to‑metal joints will benefit from the application of suitable sealing compounds during manufacture. Welded joints shall be cleaned off smooth on surfaces that are exposed when the window is in the closed position and where the joints would otherwise project into the glazing space. 7 Glazing Windows and doorsets shall be glazed in accordance with the recommendations given in the relevant part of BS 6262 and BS 8000‑7.
NOTE Attention is drawn to the glazing safety recommendations of BS 6262‑4, particularly the requirements for marking the glass.