How to Prefab an Outhouse

This facility has seen better days, but is the basic type of outhouse structure.

An outhouse is a protective shell for primitive sanitary facilities. The building part can range from a simple roofed wood frame structure to a sophisticated little house including heat, light and a hand-washing station. In times past, outhouses were frequently "pre-fabbed," and a favorite method of maintaining this little building was to move it to a new location and to back-fill the original septic hole. Directions given here will be for a basic one-holer without added amenities.

Things You'll Need

• Two inch by four inch lumber
• Two inch by 12 inch lumber
• One inch by 6 inch lumber
• One inch by 2 inch lumber
• Felt roofing paper
• Asphalt roll roofing
• Saw
• Saber saw
• Hammer
• Nails
• Drill
• Carriage bolts
• Wood rasp
• Sand paper
• Toilet seat (optional)

Instructions

Creating the Pieces

1. Cut two two-inch by four-inch boards five feet long, and two two-inch by four-inch boards six feet long. Nail them together to create a five foot by six foot, six inches -- outside measurement -- rectangle. Cut two more two-inch by four-inch board five feet long.From the outside edge of the rectangle on the six foot side, measure 30 inches and mark the spot. Make a corresponding mark on the other six foot side. Insert an added five foot board at the mark, and nail it into place. Place the second board next to the first one, and nail it into place also. The thirty inch space behind the boards will be the BACK of the outhouse, and the 36 inch, more or less, space in front of the boards will be the FRONT of the outhouse. Cut one inch lumber that will reach from the back edge of the front two inch by four inch board to the outside edge of the front of the rectangle. Nail them in place. This will create a front platform for feet, and a space to fit over a septic hole or waste containers.

2. Use two inch by four inch lumber to create a rectangle of wood that is six feet tall by five feet wide. Insert two upright studs in the rectangle. If desired, add framing for air vents or a clean-out door. This is the back wall.

3. Use two inch by four lumber to create a rectangle of wood that is seven feet tall by five feet wide. Cut three additional boards, that will fit inside the rectangle, from top to bottom. Measure over six inches from one side of the rectangle on the five foot edge, and insert one of the boards. This will be the opening side of the door. Measure over 36 inches from the inserted board on the five foot edge, and insert the other two boards, side by side. This is the hinge side of the door. Nail everything together. This is the front wall.

4. Cut six two-inch by four-inch boards six feet tall, and four two-inch by four-inch boards that are seven feet tall. Lay out the boards on a level surface, using one six foot board as the base, and placing a six foot board at the back edge and a seven foot board at the front. Make sure the corners are square. Lay a fourth two-inch by four-inch board across the ends that are not against a board. Let it extend about six inches on either end. Make lines on the uprights where the board goes across them, creating an angle on the ends. Cut along the lines. Use the set of boards as a pattern for the angles on the second set of boards to make sure both sides have the same angle. Nail the sides together. These are the side walls.

5. Nail one inch thick boards to the outside of the prepared wall frames, leaving the 36" door space open. If you use planks, nail one inch by two inch boards -- sometimes called furring strips -- over the cracks; if you use plywood or a similar covering, you can skip the furring strips.

6. Cut two two-inch by six-inch boards the same length as the sloped boards on the side walls. Cut five two-inch by four-inch boards five feet, five and five/tenths inches long. Nail the first two boards to the ends of the five foot, five 5/10 inch boards, creating a hat that will fit on top of the walls. Cover it with the same material used to cover the walls, then top it off with a water-proof barrier such as asphalt roofing material. This is the roof.

Fastening the Walls, Roof and Floor Together

1. Stand the back wall up on the hole side of the platform. Nail it on with double-headed nails or with regular nails that are not driven in all the way.

2. Stand the side walls up on the ends, with the short ends against the back wall. Nail to the platform and to the back wall using double headed nails or not driving regular nails in all the way.

3. Stand the front wall on the front edge of the platform -- the part with the solid floor, matching the top to the high end of the side walls, and fasten down using double-head nails or regular nails not nailed in all the way.

4. Drill holes in the uprights and in the floor plates at regular intervals at the various joins. Thread carriage bolts through the holes and tighten down securely. Remove the temporary nails.

5. Place the roof piece over the top of the structure. Secure temporarily using double headed nails or regular nails not driven in all the way. Drill holes in the side boards. Thread carriage bolts through the holes, and tighten securely. Remove the temporary nails.

Making the Seat

1. Measure up two feet on the inside of the side walls. Mark across the two inch by four inch boards above the open space in the platform on the side walls and across the back. Nail support two inch by four inch boards to the walls along the lines; but be sure not to nail the side and back walls together. That would make it hard to take apart later.

2. Cut two two-inch by four-inch boards the correct length to reach across the front opening of the platform hole. Nail a twenty-four inch piece of two-inch by four-inch lumber on the ends of the boards, creating a rectangle that will fit on edge from one side of the structure to the other, with its bottom edge resting on the edge of the open part of the platform. Add upright bracers at twenty-four inch intervals, then cover the front side of this structure with the same material used on the outside walls. This will form the splashboard and front support for the seat.

3. Measure the distance across the seat from wall to wall on the inside, and cut three two-inch by twelve-inch boards to fit. Lay the boards out on a level surface, just as they would be arranged inside the outhouse, and draw an egg-shaped oval for the seat hole. If you happen to have an old toilet seat handy, the inside of the seat makes a good pattern.

4. Separate the boards. Use a saber saw to cut along the curved lines. Place the boards back together, and nail a two-inch by four inch connector board across the bottom, leaving room at the edge for the two-inch by six inch boards to rest on the two-inch by four-inch frame. If desired, these pieces may also be bolted together.

5. Use the wood rasp to rough shape the edges of the opening, then sand smooth with sandpaper. Fasten on a commercial toilet seat, if desired. Settle the seat assembly on the supports in the building.

6. Dig a hole slightly smaller than the floor opening and deep enough to accommodate the waste or place a large water proof container under the opening.

The door

1. Create a solid door by cutting a piece of plywood the size of the door, or cutting one inch planks to fit the door frame. Nail a one-inch plank across the door about 1/3 of its length from the top, and one 1/3 of the way up from the bottom. Cut another board to fit diagonally across the door between these two boards. This will fasten individual planks together. If you are using plywood, the boards will reinforce the door and help keep it from warping.

2. Use hinges or leather straps to attach the door to the doubled two-inch by four-inch door facing.

3. Add a leather loop and a button or a hook and eye hardware assembly to fasten the door from the inside for privacy. Or install a regular door knob or screen door latch.

4. If secure privacy is not an issue, simply hang a curtain over the door. An opaque shower curtain works nicely.

Tips & Warnings

• Keep a container of ashes or sawdust in the outhouse to cover waste.

• Rig a holder for toilet paper.

• Place a basin, water container and soap just outside the building.

• Air vents or a clean out hatch on the back of the facility can make caring for it and using it more pleasant.

• Always check with local utilities before digging.

• Check local regulations on sanitary facilities before setting up an outhouse.

• If you are planning to use your outhouse more than a day or two, you may want to add an exhaust pipe running from the dug out hole up through the ceiling to vent any gas build-up.

References

• The Humanure Handbook: A Guide to Composting Human Manure by Josepth Jenkins, 2005.
• Outhouse Equipment
• Thinking About Building an Outhouse?