Originally Posted by
Toeslider
Yeah, like if your frame you have now is 2 feet wide by 4 feet long, just cut a 2' x 4' piece of plywood, or even OSB (cheaper), turn the whole thing over and run some screws into each piece of existing wood. It will keep the frame you have now from shifting out of square.
Imagine you have a picture frame that just has the sides. It is easy to apply a little pressure and shift the whole thing so it isn't square anymore, but if you have a back on it you can't do that. This is the same thing, it is just lying down on the floor.
ok, I did say I was a bit of a ****** when it came to building so I had to expect someone to explain in detail. I get the idea of the plywood

. I was just confirming you meant the bottom and not the top. Someone else recommended the top which isn't an option. I like the carpet/rubber option. I'd like to make a step somehow but not sure where to put it or how to design it. Getting on without a step is a bit cumbersome.