Floor Question

[les45]

Newbie question about floors. I plan to use an uninsulated 5X8X 3/4" plywood deck flush with the frame edges and 2X4 cleats for fastening the two sides flush with the frame edges. Is there anything wrong with waterproofing the bottom of the plywood and bolting it directly to the trailer frame without the 2X2 framework that I see on most installations? My logic is to gain the extra 1 1/2" of headroom.
I have not seen this type of deck construction in any of the pics or videos of actual projects. I will be insulating the top only since I will be camping mostly during the two moderate seasons here in sunny South Carolina.

[absolutsnwbrdr]

Thats exactly how I built my first. Worked out well for me.

[eaglesdare]

i bolted mine down directly to the frame also.

[terryjones1]

I screwed my 1/2" plywood floor directly to the frame.
See photo below.
The lowered part of floor in lower right is a "dropped" floor.