What are acceptable viewing standards for residential glass?
• Both panes of the glass sealed unit should be viewed at right angles to the glass from the room side at a distance of approx 2 metres in natural daylight (not direct sunlight). The area to be viewed is the normal vision area, with the exception of a 5 cm wide band around the perimeter of the unit. Flat glass shall be deemed acceptable if the following phenomena are neither obtrusive nor bunched: • Totally enclosed seeds, bubble or blisters • Hairlines or blobs • Fine scratches not more than 2.5 cm long • Minute embedded particles Obtrusiveness of blemishes is judged by looking through the glass, not at it, under normal daylight conditions as described above.
