BS 644-2012 pdf free download

BS 644-2012 pdf free download.Timber windows and doorsets — Fully finished factory-assembled windows and doorsets of various types — Specification.
The coating system shall be selected in accordance with BS EN 927-1 and shall meet the criteria for stable end-use.
The coating system shall be assessed in accordance with BS EN 927-2:2006 and shall meet the performance criteria for stable end-use under medium exposure conditions. The coating shall also meet the requirements of the optional tests within BS EN 927-2:2006, Table 2 for being mould-resistant.
7 Fabrication
7.1 Profile design
Windows and doorsets shall be designed to be glazed in accordance with
BS 8000-7.
The glazing rebate sizes and design shall be appropriate for the glazing and the glazing method.
For drained and vented glazing systems, the profile shall be designed such that water is prevented from accumulating anywhere within the rebate. Any drainage channels shall be kept clear.
Unless otherwise agreed (see Note 1), exposed arrises shall be replaced with a radius of not less than 3 mm to avoid thinning of the coating system.
NOTE 1 There might be circumstances where it is not acceptable to have a radius of 3 mm, e.g. owing to planning considerations. Under these circumstances, a smaller radius may be applied with the agreement of the coatings supplier.
Sills and sill nosings shall have a throat formed in their undersurface adjacent to the front face to prevent water running back across the underside of the sill. Sill members shall finish flush with the other main frame components.
When installed, sill nosings shall be designed to shed water away from the window or doorset and over the construction below the window or doorset.
NOTE 2 Sill nosings may be In timber but should not exceed 100 mm in width to avoid distortion or rapid deterioration of the coating system, in formation to this effect should be included with the manufacturer’s installation information (see Clause 9).
The exposed top surfaces of horizontal members of frames, casements, sashes, door leaves, sill nosings and glazing beads shall be profiled or angled, with a slope of not less than one in eight (70), to shed water from external surfaces.
The top surfaces of internal horizontal members of windows or doorsets shall, where practicable, be profiled or angled to shed any water from condensation or cleaning away from the internal face of the glass and the glazing rebate.BS 644-2012 pdf free download.