Wood Enclosure

• If building a wood enclosure for the utility trailer, it must be secure going down the road. The last thing an operator needs is for the enclosure to come loose or, worse, come off in a 50-mile-per-hour headwind on the highway.
  
  Create a frame using 2-by-2-foot pieces and secure them to the trailer floor with angle brackets. Space the vertical supports every 18 inches. Attach horizontal pieces every 24 inches from bottom to top. Use woodscrews over nails for this procedure. Connect the two sides, front and rear with transverse 2-by-4 studs. Cover with 3/8 plywood cut to size. Again, attach with screws. Seal all joints with caulk and thin strips of aluminum flashing. Install a door where convenient.
  
  

Soft Enclosure

• Contact a marine supply store for a waterproof material large enough to enclose the wooden frame. Reinforce the edges with grommets at a maximum of every 12 inches. Cover the wooden frame with the cut-to-size fabric and secure with line to the trailer frame at every grommet.
  
  The advantage of the cloth enclosure is that it can be removed in the event any outsized tall or wide items need to be loaded on the trailer.
  
  

Metal Enclosure

• Although involving more work than maybe a home hobby craftsman wants to perform, a third option for enclosing the utility trailer is using metal. Complete the wooden frame as described above. Using corrugated galvanized sheeting, install with panhead screws around the frame and the roof. The corrugated galvanized sheets can be overlapped to ensure a good seal. Apply a layer of caulk between each seam to make the trailer water tight.
  
  The advantage of the metal frame is, once painted, it will stand up to weather for much longer than any other material. The disadvantage is the interior of the trailer may be insufferably hot in high summer.