Here's my Recipe, for a Waterproof Instant Garage, or Trailer Tent!!
You'll need: (Depending on the size of your trailer)
1 or more, empty "Pringles can(s) w/plastic lid(s)" (for pitch)
Cotton clothes line, lots of it!
4 to 6 (1/2") PVC pipes
6 or more thick rags (cheap washrags work great)
Thick Plastic Sheeting (enough to cover top as far down the sides of your trailer you want
1 UGLY TARP w/gromets
Prep: Use old punch type can opener to punch 3 or 4 holes into the bottom of each can, then punch holes (or cut them) into the cardboard side just below the holes in the aluminum lip.
Tape half of each rag folded into fourths, onto each corner of the trailer, toward the top middle. And tape one to the "middle of the roof."
Thread one end of your clothes line thru opposite can holes, make it as long as you need it to be, to reach opposite corners of the trailer. (looping it thru the holes will give it more support)
Thread each line thru one piece of PVC pipe. (Make sure you cut line long enough to reach your tie off point on both ends) You are making an X on top of your trailer. It should begin to look like you're making an umbrella.
Loop or tie into the opposite rope at the punch out can "top". Put the "pringles can(s)" with the lid on it, upside down, on the roof. (plastic lid on the rag. Pull each rag up over the end of the pipe, and tape it. THIS IS YOUR FRAME. Tie it off, to your trailer.
Tie a tight knot or 2, into each corner of your plastic sheeting and tie them down with cotton line, to your frame. Put UGLY TARP over the top of the plastic "tarp."
TIE off GROMETS! Square off UGLY TARP at the corners. It's used as a "CAP." You can use old 1 GALLON water or milk bottles to hold it down, via line thru accessible gromets.
Check tarp a couple of times the first month, to make sure lines are snug. This should last 2 or 3 winters. I you take care of it. Not bad for a Trailer Tent that costs about $25. to build, depending on the size you need.
The rags will protect the trailer, & tarps from frame rubbing holes in them. Goo Gone will take off residual glue from tape.
PS if you need more "pitch," try putting an empty paper towel roll inside 2 pringle cans, taped together.
If you need a graphic look at the design, let me know... I'll see what I can draw up. Good Luck!