I made a gypsum board ceiling, and the carpenter added a layer of joinery board between the gypsum board and the light steel keel. Can the main light be directly installed on the blockboard?

Depending on the weight of the main lamp, it is not allowed to exceed 3kg.

The Code for Acceptance of Construction Quality of Building Electrical Engineering stipulates that the fixing and hanging devices of large lamps should be embedded and installed after construction design and calculation. In order to check whether its firmness meets the requirements of the drawings, an overload test should be carried out.

When the weight of lamps and lanterns is more than 3kg, hooks should be embedded in the top surface of the original building, and the diameter of hooks is less than the diameter of hanging feet of lamps and lanterns or less than 6mm, so the overload test should be twice that of lamps and lanterns.