Bill wrote:


I was hoping to use the 3/4" floor as a shelf, for stuff like drills
and what have you. Maybe in addition to the two2 2by4s shown, under
the floor, I could add 3 more going the other direction. The simplest
joinery would be to screw them to the floor from above, but I'm not
confident whether that will give satisfactory performance.


Yeah - I kinda figured you'd want to use that base as a shelf. That 3/4"
plywood will be plenty strong enough all by itself though, to carry any
weight you're going to want to put on it, with no 2x4's under it. You might
want to put a band around it that is higher than the shelf itself, to form a
lip so that items can't roll or slide off the shelf so easily. That band -
even if it is only made out of 1x2 will add strength, all by itself - though
you don't really need it for what you're doing. Your span down there just
is not that great. You'd be just fine with nothing more than the 3/4"
plywood. All the rest is just up to your preferences. And... that's a part
of all of it, just as well.

--

-Mike-