Thanks. I’ll add some blocking. Makes perfect sense.

I can still use 2x4s. Should I put them flat or vertical? Vertical I’d assume? Then I just may throw some in horizontally to prevent slippage. I went with 2x2s to make sure it couldn’t shift.

I am hoping this solution is over engineered.

I want to put my full rack in my loft on the 2nd floor. I will have it as close to the exterior wall as I can.

The joists run length ways perpendicular from the wall. I am going to build a platform using two 4x8x3/4 sheets of plywood. I will use 20 slats, 2x2, running perpendicular to the joists (parallel to the wall) to spread the weight. They will be 4” apart with two joining the middle.

The weight will be upwards of 500lbs including me near the center of the platform.

Code says that the floor needs to support at least 40lbs per square foot. I know I’m not getting full distribution, but it’s gonna be 64sqft to distribute the weight over.

I gotta imagine this will be good enough? I do not slam weights.

Any thoughts?

Here's a few pictures of the proposed design: https://imgur.com/a/VWHNiGN