There is no double-layer requirement for the glass balcony rails, but it requires the use of safety glass that is not less than 6mm (the thickness is related to the area of the single piece, and the larger the area is, the thicker the thickness is).
If the outdoor ground is more than 5 meters away from the glass, it must also be laminated glass (also a type of safety glass, in which a glass of safety glass is sandwiched between two layers of glass. This type of glass does not fall down and hit the pedestrian when destroyed). .
In addition to glass, there are structurally supported metals and other components that are required to meet strength requirements. Finally, the connection between glass and other components requires sufficient strength. If it is connected with structural adhesives, it is generally imported structural adhesives.