Construction Plans for a Custom Designed Low (Mini) Tunnel

If you intend to cover an auto tire bed, cut the pipe into 6-inch pieces. You will need to prepare 22 pieces to construct a 30-foot-long tunnel. Drill a 7/16-inch-diameter hole completely through the side of each piece of pipe 2 inches from one end. Attach the receptacles to the bed sides using 2-inch wood screws. Locate one screw in the middle of the pipe and the other 1 inch above the base of the pipe. The use of two screws will keep the pipe from rotating. When attached, the top of the pipe should be no higher than the side of the bed, and the drilled holes should run parallel to the side of the bed. Space the hoop receptacles 3 feet apart starting at the end of the bed.

If you are covering a corrugated sheet metal bed, cut the 1-inch PVC pipe into 4-inch pieces. You will need to prepare 22 pieces to construct a 30-foot-long tunnel. Attach the pipe to the 2-inch by 4-inch wood frame using 2-inch wood screws. Locate one screw in the center of the pipe and locate the other 1 inch from the base of the pipe. When attached, the pipe should be level with the top of the frame. Space the hoop receptacles 3 feet apart starting at the end of the bed.

Fabricate hoops for the tunnel out of 1/2-inch schedule 40 PVC pipe. We recommend cutting a 20-foot joint of pipe into three equal sections measuring 80 inches. An 80-inch hoop will create a tunnel about 2 1/2 feet high when used in conjunction with a 40-inch-wide bed. You will need to prepare 11 hoops for use with a 30-foot-long bed.

We recommend using 6-mil greenhouse film for the tunnel cover. Thinner film will work, but isn't as durable and will need to be replaced more often. Construction grade plastic film may be used, but will need to be replaced annually due to sunlight degradation. Porous floating row covers may be used, but only the heavier weight covers will provide any long-term serviceability due to the wear and tear on the fabric that occurs with repeated opening and closing of the tunnel.

The tunnel cover will need to be wide enough and long enough to hang over the sides and the ends of the tunnel. When using 80-inch-long hoops on a 30-foot-long bed, you will need to prepare a piece of film 8 feet wide and 38 feet long.