This standard specifies the plastic film used to form a separate moisture-proof layer to prevent dew in the heat-insulating structure, mainly when a house has a heat-insulating structure.
JIS A 6930:1997 history
2008JIS A 6930 AMD 1:2008 Plastic films vapour barrier for residential use (Amendment 1)
1997JIS A 6930:1997 Plastic films vapour barrier for residential use