Attic Flooring

[ebikeNoob]

Hi guys,
We bought an apartment (the block is only 1 floor high with retail units below) and the developer said it was OK to floor the attic for storage, so using loftlegs I've started to make raised storage areas to sort out the mess.

I was hoping to use timber joists (2"x6") to make an area to take a heavier load than 40kgs per squared meter but will the ceiling joist take it?

Here's the space, its 1.4m by 3.6m....

https://s23.postimg.org/vnzsgf50r/IMG_0022.jpg

I'm hopeful its possible as our water tank sits spanning 4 ceiling joists and that weighs between 200-240kgs.

Thanks for any help.

[koko]

what about using floor boards or plywood, ply may be better as you can get it in 1 inch thick as well as thinner