BS 6510:2010 pdf download – Steel-framed windows and glazed doors – Specifcation
6.2 Frame joints Welded frame joints shall have signifcant surfaces dressed square and fat.
NOTE 1 Signifcant surfaces are those visible after installation when windows and doors are closed and viewed from a distance of 1 m, unless specifed otherwise by the purchaser. When tested for bending resistance and torsional strength (see Note 2), sample welded corner pieces, selected at intervals appropriate to production volume and batch quantity (see Note 3), shall have their parent metal tear before failure of the welded joint.
NOTE 2 The test methods given in BS 4872‑1:1982, Clause 18 and Clause 19, or BS EN 287‑1:2004, Clause 6, or adaptations thereof, would be appropriate.
NOTE 3 Welded corner pieces tested at the start of each new production order, and at least once weekly per welding machine thereafter, would be an acceptable sampling rule for small batch production. Joints effected by mechanical means, such as cleating and screwing, shall be sealed. When tee glazing bars of solid hot‑rolled steel profle are incorporated, they shall be riveted and/or welded to frames, and shall interlock with rigid joints displaying face gaps of no more than 1 mm.
6.3 Weatherseals Weatherseals shall be clipped, clamped, or secured by adhesives. 6.4 Hardware Double‑point or multi‑point fasteners shall be ftted on opening windows over 1 200 mm long or 1 500 mm high. 7 Protective fnishes 7.1 Rust-protection Frames and ancillary profles shall be rust‑protected using one of the following methods, or otherwise treated to provide rust protection of demonstrably equivalent or superior performance:
a) hot dip galvanizing after fabrication in accordance with BS EN ISO 1461; or
b) hot dip galvanizing before cold‑forming in accordance with BS EN 10346:2009, coating designation Z200 or Z275; or
c) hot melt zinc spraying in accordance with BS EN ISO 2063; or
d) stoved epoxy zinc priming in accordance with BS EN ISO 12944 suitable for moderate environments and always over‑coated with a colour fnish.
NOTE One way of demonstrating “equivalent or superior performance” could be to compare specimen sample pieces of conventionally protected steel and of the proposed new fnish, subjecting both simultaneously to a BS EN 1670:2007, grade 4 (240 h) salt spray test.
7.2 Colour-coating Frames and ancillary profles shall be colourcoated, when required, either:
a) in accordance with either BS 6497 or BS EN 13438 with a paint thickness over zinc on signifcant surfaces of not less than 60 µm; or
b) otherwise treated to provide a colour coating of demonstrably equivalent or superior performance. NOTE Signifcant surfaces are those visible after installation when windows and doors are closed and viewed from a distance of 1 m, unless specifed otherwise by the purchaser.
8 Design for installation NOTE A guide to installation of steel windows is published by the Steel Window Association as Fact Sheet 3 .
BS 8213‑4 provides guidance on the survey and installation of replacement windows and external pedestrian doors.
8.1 Perimeter joint design gap Windows and doors shall be provided with a perimeter design gap as shown in Figure 1 that allows for thermal movement, fabrication size variance and aperture construction tolerance. NOTE 1 Gaps may vary to rationalize frame sizes measured to ft existing similar but not identical openings. Perimeter design gaps shall be not less than 2 mm and not greater than 8 mm once the frame is centralized in its opening, unless otherwise agreed (see Notes 3 and 4).
NOTE 2 To achieve this, the following rules should be observed.
a) For design opening heights and widths up to 1 m, frames should be sized 8 mm less than the design opening; actual opening heights and widths should vary by no more than ±4 mm from the design opening.
b) For design opening heights and widths over 1 m, frames should be sized 10 mm less than the design opening; actual opening heights and widths should vary by no more than ±6 mm from the design opening.
NOTE 3 When replacing windows in existing buildings, the “design” opening is the median of the range of sizes measured from actual heights or widths that are notionally similar but not identical. Actual perimeter gaps between frame and irregular openings outside the limits specifed in 8.1 can be acceptable, and effectively sealed by specialist contractors, on agreement between installer and client.