Bearing capacity in planed edgewise timber?

[öringen]

I will build a grate in the floor of the existing stairwell to the upper floor (the staircase will be torn down). I had considered grating but think it would be uncomfortable to walk on barefoot. So now the idea is to lay pine wood on edge with gaps of about 1.5-2cm. They need to support about 50cm. What dimensions would be needed for this? The thickness of planed boards is usually 21-22mm but the height is the question. It must withstand jumping, playing children, and adults, etc.

 

[KnockOnWood]

If you excuse me, I don't think the construction you're sketching is sensible.

gaps about 1.5-2 cm
jumping playing children

I envision many broken toes and also some fingers when the children play on this grid

Maybe you should invest in a sheet of makrolon/polycarbonate instead.
With some anti-slip strips attached.

 

[useless]

What is the purpose of the grid?

 

[öringen]

It might happen that I make slightly smaller gaps, like decking approximately. The question was what dimension you think is required to compare with regular decking wood that is on cc60. It should hold for foot traffic.

 

[vanpire]

If it is ventilation that the grid is supposed to ensure, perhaps a sheet with X number of drilled holes could serve the same function?

 

[öringen]

What is the purpose of the grille?

Heat transfer. Utilize existing stairwell, avoid changing the ceiling in the room below. Avoid fans to transfer the heat (which I imagine cannot move as much air as the existing stairwell).

 

[öringen]

If the grill is meant to ensure air exchange, perhaps a board with X number of drilled holes could serve the same function?

I've also thought about that, but what kind of board would it be, and how many holes can be drilled before it becomes too weak? I've also considered laying the pine floor that's going to be installed upstairs over the hole and then adding several round vents with grills in them. But I'm not sure if it would weaken the floor too much.

 

[öringen]

Have also looked at these products. But I'm considering building something myself that will rest on joists.

http://www.kungsprofiler.se/galler/galler/tragaller_for_golv/

 

[mexitegel]

If it is to hold up, you need to frame a floor structure, check span tables. Then it's not a problem to make some holes for vent grills, but wouldn't it look nicer to place rectangular ones next to a wall?

 

[öringen]

If it has to support foot traffic, you will need to install a framework with joists, check span tables. Then there's no problem to make some holes for vent grilles, but wouldn't it look better to place rectangular ones next to a wall?

Yes, if I lay the floor over it, there will be extra support joists in the hole. The floor will be 25x158mm pine. I was thinking about installing several round vents (100mm in diameter). If you drill the holes so the center is at the seam between two floorboards, then insert cast iron grilles and countersink the grille rim to be flush with the floor.

 

[Rabbithole]

Holding it securely with 30mm is fine but 28x70 and a 5mm gap should work, it might look nicer with 45x120 studs. It feels stable at least.

Perhaps I would have built a frame with mitered corners and then screwed from the outside into the studs. Built a frame underneath to place the grid on. All in 45x120.

 

[öringen]

It will certainly hold with 30mm but 28x70 and 5mm gap should work, maybe it will look nicer with 45x120 beams. It feels stable anyway

Maybe I would have built a frame with mitered corners and then screwed from the outside into the beams. Built a frame underneath to place the grid on. All in 45x120

You understand the way I'm thinking. I was also thinking of a mitered frame around it. Building the grid from 45x120 beams will be stable, however, it reduces the amount of air since the beam takes up more space.

 

[öringen]

Thank you for the feedback. More ideas are gratefully received.
It might be a completely crazy idea, but I like old houses with some unusual solutions