Stability of OSB boards

I want to convert my roof space and primarily use it as storage. The attic floor consists of wooden joists spaced one meter apart. I now want to screw OSB boards onto them. The salesperson at the hardware store advised a board thickness of 22 mm. He also saw no problem with some of the board joints lying directly between the joists. That seems a bit weak to me, but I also don’t want to always place the joints exactly on a joist for more stability. What do you think, are the boards stable enough? I also want to store some heavy furniture in the attic.

Butting panels between the rafters is not possible, as this will become unstable; furthermore, the distance of 1.0m is too wide for most floor covering boards, certainly for the 22mm board. I once consulted a table for the load-bearing capacity of OSB boards: with a support spacing of 1.0m and a board thickness of 25mm, you reach a maximum permissible live load of 1.0 kN/m². This is barely enough to designate an attic as walkable. For storage purposes, this is not sufficient; I assume (analogous to the live load of balconies) about 4.0 kN/m², which you would need to achieve with your floor construction. It is best to inquire with a manufacturer of OSB boards and describe your project; they will certainly explain the best option (type of board, board thickness, support spacing).

Thank you Hertweck, I can work with the answer. I will inquire directly with the manufacturer.

Hi,

I have this idea, or something similar. That is why I am looking for solutions. I have therefore inquired about these OSB boards. This is a good and inexpensive option. These OSB boards are well suited for interior construction. Here I am using the OSB2 board.

I also used these OSB boards for the attic. I decided on a thickness of 22 mm. I placed some furniture on the floor and I think this thickness is the right one.

Okay, the rafter width is one meter, so not a large distance. I have also installed OSB panels and they have a thickness of 30 mm. That is sufficient and loads can also be stored here.