July 4, 2012 I bought a 4 x 8 Harbor Freight Haul Master Folding Trailer, to haul my motorcycle's.
Assembled it in my garage, pretty straight forward design.
I had seen one at a gas station with a diamond plate steel deck, that had been painted and sanded. The owner told me the diamond plate was very expensive, looked nice unpainted, but it was too slippery. He regretted not using plywood.
I put plywood decking on with a removable locking front wheel chock. It worked well for me. All that said, don't let anyone fool you into thinking that you will be folding it and STANDING IT UP on its casters without help. You have to unpin and unbolt the folding parts, flip the back over onto the front. At this point you should secure the two half's together.
Now start lifting both half's up on to the casters, while the tongue drops down. You're trying to tip 150 to 200 lbs or more.
If you try to do this on smooth concrete the caster support won't have anything to bite into and will just slide away from you.
If you happen to be built like "The Rock" aka Dwayne Johnson it shouldn't be a problem. I'm over 6 foot I couldn't do it safely by myself. I ended up buying a electric hoist. I attached the hoist to the ceiling joist in the garage. That was the only way I could safely fold and stand the trailer up for storage.
Good Luck.
DW