Teardrops n Tiny Travel Trailers

I got my trailer frame and I am getting ready to get started. I'ts a 5'x'10' built with 2" tubing with 1 1/2 angle flush with the top on 24" centers for bracing.

If you look at the second pic in the url below I was going to attach 3/4 treated ply to the frame with bolts, and have a 1/4 overhang on the sides. On the sides I was going to use 3/4 non treated with a 1/4 mortise cut. I was going to have the sides come down flush with outside of the frame bottom. Then also bolt the sides to the side rails. I have four questions:

1. On most plans I see that there is a 3/4 rail mounted on all the frame parts and the floor is set on that. Is it Ok to mount the floor directly to the frame or should I put on the 3/4 x 2" wood rails?

2. What would be sufficient spacing for the bolts on the bottom and sides?

3. What should I treat the side wood where it contacts the frame and the exposed edge on the bottom with?

4. I was planning on putting in a false bottom for storage, hence the treated bottom. If I used exterior ply instead of treated would I be in for rot in a few years (I live in the humid south). I guess I am asking what is the best way to keep the floor from rotting.

Any suggestions would be appreciated.

https://picasaweb.google.com/114208724970218454913/TrailerDiagram?authuser=0&feat=directlink

For what it's worth, here are my answers

1) I'm not really what the reasoning behind adding a 3/4" wood frame over the steel frame is. I can't think of any advantage that you might gain. I do think someone said they needed the depth for some reason. Other than that, not sure you gain any advantage. I bolted my floor directly to the frame

2) I spaced at 16" centers. Not sure why other than that's a standard distance in the construction trade


3) I treated all raw surfaces of wood with asphalt based fence post paint from Tractor Supply Co. There's also all the gooey black stuff from Henry's that can be used. Lots of people treat raw edges with CPES from Rot Doctor. You can also make your own mix of 75% mineral spirits to 25% polyurethane (Varathane or similar)

4) If you properly treat the bottom with one of the materials above (be very thorough) you should be fine using a good grade of plywood. I did not used treated because I hate the way the stuff smells and due to all the precautions you've got to use when handling/sawing it. I'm also not sure if this stuff off-gasses and just thought it's a case of better safe than sorry.

Hope this helps

That's what I am looking for someone's advice who has done it, Many Thanks!! I was worried about using treated with the fumes and stuff.