When should I double stagger panels?

With non-load-bearing dry fillers, select the boarding for the floor finish. For a thick or rigid floating floor, such as multilayer parquet or laminate, one 22 mm OSB or Durelis board may be sufficient if a timber reinforcement strip is screwed below every joint in each 50 × 50 cm grid space. For thin, flexible finishes, such as cork, carpet or vinyl, use double boarding: first 12 mm and then a staggered top layer of at least 18 mm; screw the top board into the lower board. Use screws approximately 2 cm longer than the board thickness. With load-bearing dry fillers, follow the instructions for the selected board and floor system, as the permitted build-up can differ by system.