Laminated glass shall conform to BS 952-1 part 1- section 4 and shall be an approved proprietary product comprising two toughened glass sheets bonded together and incorporating an interlayer to the performance specified. When incorporated in the works, all edges shall be effectively sealed against the ingress of moisture or any other medium or condition which could result In delamination. No bubble of P.V.B. laminate shall be acceptable in the visible body of glazing. At ·resin/tape Interface one bubble per meter of max 3 mm. shall be acceptable, other than on open edge of laminate ie. visible glass.