Teardrops n Tiny Travel Trailers

Hey guys, So I have my frame/floor built and the next step is to attach it to the frame. I used treated, exterior grade 2x4 and plywood without insulation. My question is what should I coat the bottom with that will endure the weather/ water coming up off the road. I am not covering it with aluminum on the outside, so If i can get sealant that I can use for the underside and exterior, bonus. What do you think?

Most people seem to use that black tar based waterproofing goop

Asphalt paint

I got a gallon of Black Beauty fence post paint from tractor supply near my house
http://www.tractorsupply.com/tsc/produc ... _vc=-10005

easiest stuff I could locate. three coats on the bottom of mine and I'm pretty comfortable with it.

What about using :

Vycor Plus 6 in. x 75 ft. Roll Fully-Adhered Flashing

or

Nashua Tape 6 in. x 75 ft. Select Window and Door Flashing Tape

A butyl based flashing tape. I saw it used in a video teardrop build ( Scott 2010 ?? ) I have used it around windows. Adheres well to wood/plywood (unfinished/unsealed??) No smell. Easy to handle. Nothing to stick to after applied. Follows contours well. High temperature range (20F - 180F). Obviously will work on house to temperatures below this. Designed for what you are trying to do -- seal out rain driven water and air-infiltration and mold. Overlapped properly (1 in or so), should be really quite a good seal.

May not be good enough for cold conditions.

Personally thinking this will work for my build ( off in the future. I have not built a teardrop using this yet. )