Joist dimension (billiard table upper floor)

[s60]

Hi!
I need help choosing which type of joist to use.
The longest span I have is 520cm on the upper floor where there are 2 bedrooms.

My other thought is where I have a span of 380cm where I was planning to have a LARGE and heavy pool table.

Should I go for plywood joists, Masonite joists, or what do you suggest and what dimensions should I aim for??

Best regards

 

[miry]

I think you need to define the question a bit more.

Are you building a house or do you live in a house with a floor that has 380 in span in one direction and 520 in the other direction?
And what is it you want an answer to?

Are you making a floor where you have 380cm in span towards a support and you want to know what you should have in that floor for it to support a pool table or what is the question?

 

[s60]

I'm working on building a house, and the span is the measurements I've written. What I'm wondering about is what to use for the floor structure as I ideally don't want any flex in the floor where the pool table will be... what center-to-center measurement is required, etc. I plan to contact a company but want to have some more "meat on the bones" before I talk to them... and the upper floor is about 5.5 meters * 12 meters so the measurements I wrote earlier are the span between the load-bearing walls.

Best regards

 

[miry]

it would be helpful to see drawings of how everything looks and then I checked and saw that a pool table doesn't weigh more than 100kg and that's no more than a regular person :blushing:

but if you say you're using 45x220 with C/C 600mm, the deflection in the middle would be about 2mm with a point load of 100kg and 3.8m and about 5.5mm deflection with 5.2m

then you can reduce the deflection somewhat by using a sheet material that can take some of the load, which can stiffen everything up, but you still won't get the deflection down to what it should be designed for if you're going for 5.2m and not using glulam beams (which become much more expensive)

so if you go down to 45cm in c/c and a tensile material in the ceiling below, you might be able to get down to 2mm, and that's quite acceptable at least

 

[s60]

Thank you for the answer. I'm counting on a "real" table weighing several hundred kg, but I'll check it out.. But Kerto beams are probably stronger than 220*45 and cheaper than glulam, so maybe that's what we should go for.. I'll check if I can sort out the drawings so you can get a better look at how they look..