Outdoor privies are in use all over the world on both a temporary basis and as the permanent alternative to indoor plumbing. For convenience, farmers and ranchers who work large areas of land build and use outdoor privies. Residents of long-term campsites find the use of outdoor privies a luxury compared to the obvious alternative. Your privy must meet basic construction guidelines to ensure as much comfort as possible and also to conform to basic health and safety guidelines. The better it is constructed, the more enjoyable your privy will be to use and to be in close proximity to it.
Dig a waste deposit pit 2 feet square and 5 feet deep. The bottom of the pit must be at least 3 feet above the water table, and the sides of the pit should be as straight up as possible.
Dig four post holes 2 feet deep and 6 inches in diameter. These holes should form a perfect square, with the two rear post holes on a line with the back edge of the waste deposit pit.
Form the front of the privy by placing two 4-by-4-by-72-inch corner posts in the two holes farthest from the edge of the waste deposit pit. Fill the holes with dirt and tamp down firmly.
Form the rear of the privy by placing two 4 by 4 by 66-inch corner posts in the two holes nearest the edge of the waste deposit pit. Fill these holes with dirt and tamp down firmly.
Frame the inside of the corner posts by nailing four 2-by-4-by-48-inch boards at the base of the four corner posts, on the inside of the privy. Use a carpenter's level to ensure that the boards are level.
Repeat the framing process with the 2-by-4-by-48s in the middle of the upright corner posts, on the inside of the privy.
Nail 2-by-4-by-48s, on the inside of and extending from the tops of the 72-inch corner posts down to the 66-inch corner posts. Place these boards so that half of the width of each board is 2 inches above the tops of both corner posts. These two boards will form a frame to which a slanting roof will be attached later.
Attach a 2-by-4-by-48 on the inside of and flush with the top of both the 72-inch corner posts and the 66-inch corner posts.
Use a jigsaw to cut single sheets of 1/2-inch plywood to nail to the corner posts to form each wall for the two sides and the rear of the privy. Leave the front of the privy open for now.
Measure and cut a 56-inch square of 1/2-inch plywood, and nail it to the top of the two corner post braces to form the roof. There must be at least a 4-inch overhang on each side of the privy.
Nail wire mesh screen between the roof and the top of each wall to form an insect barrier to cover the vent space between the roof and the walls.
Cut a 44-inch square of 1/2-inch plywood and nail it to the four 2-by-4s that frame in the bottom of the corner posts to form the floor of the privy.
Draw a pencil line 18 inches from the floor on the walls of both sides and the rear of the privy. Use a carpenter's level to make certain the lines are level. On the two sides, place a 2-by-4-by-48 board so that the top of the boards are level with the lines, and nail them to the corner posts.
Cut a 1/2-inch plywood board 36 by 24 inches to form a bench that will rest on the 2-by-4-by 48s. Cut a hole in the board with a jigsaw that is one foot in diameter and that is centered in the middle of the waste deposit hole.
Place the board on the two 2-by 4s and attach it with nails. Attach two 2-by-4-by-18s, evenly spaced against and standing upright on the rear wall, to act as supports for the back of the bench.
Attach a piece of 1/2-inch plywood board measuring 48 by 18 inches to the front of the bench.
Install a tightly fitting seat made of an 18-inch square of 1/2-inch plywood over the hole in the bench. Attach the cover with two hinges at the rear of the hole. Install a spring attached to the middle of the cover to either side of the hole in the bench to close the cover firmly.
Paint the inside of the privy with two coats of polyurethane paint to prevent the wood from absorbing odor. Paint the outside with outdoor weather-resistant paint.
Drill a 3/4-inch hole in one side of the bench next to the seat cover. Drill a matching hole in the roof.
Attach a 3/4-inch PVC pipe extending into the hole for a distance of 12 inches and extending above the roof for 12 inches. This pipe will act as a vent for the waste deposit hole.
Caulk around the pipe where it penetrates the bench and the roof.