Installing a bathroom in your cargo trailer gives you the freedom of having a bathroom on hand even in the remotest of places. Using some basic materials and a little mechanical knowledge and guidance, constructing a bathroom in your cargo trailer can be easily done. This bathroom will be a 4 foot by 4 foot enclosure and have all the amenities of a regular bathroom with a working sink, toilet and shower.
Installing the Privacy Wall
Measure and mark a spot 4 feet into the trailer from the front wall and 4 feet into the trailer from a side wall. This will be the spot for the vertical support post for the wall.
Place one of the 8-foot long 2x4s vertically from the floor of the trailer to the roof at the spot marked in Step 1. This is the vertical support post for the wall.
Attach the 8-foot long vertical 2x4 to the trailer roof and the floor using screws and L-brackets.
Measure and mark a spot on the front wall 4 feet over from the side wall of the trailer.
Place the second 8-foot long 2x4 vertically on the spot marked in Step 4 on the front wall. This 2x4 should be vertical but parallel to the vertical support post you attached in Step 3.
Attach the second 8-foot long 2x4 to the front wall with screws. This creates a second vertical post for support of the privacy wall.
Attach the 4'x8' sheet of ½-inch thick exterior plywood to the two vertical posts using screws. This will create a privacy wall 4 feet wide by 8 feet high.
Installing the Shower
Measure and mark a spot about 6 feet from the floor on the privacy wall. This will be where the brass clothes hanging hook will go for hanging the solar shower bag.
Attach the brass clothes hanging hook to the wall using screws at the spot marked in Step 1.
Hang the camping solar shower bag onto the brass hook.
Measure and mark a spot on the trailer floor 2 feet out from the privacy wall and towards the side wall that the brass hook is pointing to. Then drill a 4-inch hole into the floor of the trailer at this mark with a 4-inch circular cutting bit. Glue a 5-inch stainless steel sink strainer in place over this hole with epoxy glue. This creates a drain outlet in the floor for the shower.
Installing the Toilet
Measure and mark a 1-½ by 1-½ foot square on the floor of the trailer along the trailer's side wall where you are placing the bathroom. This will be the area where the portable toilet will sit.
Attach the 1 ½-foot long 2x2s to the floor of the trailer on the lines drawn in Step 1 using screws. This will create a square of 2x2s that measures 1-½ foot by 1-½ foot.
Place the portable camp toilet into this 1-½ foot by 1-½ foot square. It should rest securely in this spot so that it will not shift while the trailer is moving.
Installing the Sink
Measure and mark two spots on the same horizontal line 4 feet up from the floor on the side wall of the trailer next to where the portable toilet is placed. This will mark the spot for the sink's countertop.
Measure and mark two parallel lines running 2 feet down from the marks made in Step 1 towards the floor of the trailer. These lines need to be 2 feet apart from each another. This will mark the spots where the sink countertop supports will go.
Create two 2 by 2 foot squares with the 2-foot long 2x4s by attaching them to one another on their ends using screws and flat brackets. This will create two 2-foot high square supports on which the sink's countertop will rest.
Attach the two 2 by 2 foot squares to the wall on the lines marked in Step 1 using L-brackets and screws. You should now have two parallel, 2 inch wide by 2 foot long support squares made from 2x4s sticking out from the side wall of the trailer.
Attach the 2'x2' sheet of ½-inch thick exterior plywood to the support squares using screws. This should now create a countertop next to the toilet on the side wall of the trailer and opposite the shower wall.
Place a 16-inch pizza pan into the center of the countertop. Using the pizza pan as a template, draw a circle on the counter with a pencil. This will give you a 16-inch diameter circle on the sink countertop. Then drill a ½-inch hole at a point on this circle.
Cut out the 16-inch diameter circle by placing a jigsaw blade through the hole made in the countertop in Step 6 and then cutting along the guideline.
Measure and mark a spot 3 feet up from the floor of the trailer on the side wall underneath the sink counter. This will be the exit hole for the drain pipe from the sink. Then cut a 2-inch circular hole at this spot with a 2-inch circular cutting drill bit. This is the exit hole for the drain pipe from the sink.
Glue an 18-inch diameter mixing bowl into the 16-inch diameter hole that has been cut into the counter. Use epoxy glue to secure the bowl in place.
Cut a 2-inch circular hole in the bottom of the mixing bowl with the drill bit. Then glue one end of a 3-foot long garden hose into this hole.
Measure and mark a spot 1 foot down on the garden hose from the bottom of the sink bowl created in Step 10. Then bend the garden hose into a U shape at this spot and push the other end of the garden hose through the hole in the side of the trailer wall underneath the sink countertop. Glue the other end of the garden hose into the drain hole.
Place a 5-gallon water jug on the sink countertop with the valve spigot opening into the sink bowl. This will allow the water to pour from the jug into the sink then drain out of the garden hose drain pipe.
Installing the Privacy Curtain
Measure and mark a spot on the side wall of the trailer 6 feet high from the floor on the open end of the bathroom cubicle.
Measure and mark a spot on the privacy wall vertical support 6 feet high from the floor on the open end of the bathroom cubicle. This mark should be on the same horizontal line as the mark on the side wall of the trailer.
Attach a 4-foot long shower curtain rod to the wall and vertical post using screws on the open end of the bathroom cubicle at the spots marked in Steps 1 and 2.
Attach the shower curtain hooks to the shower curtain rod then attach the shower curtain to the shower curtain hooks. This will enclose the bathroom cubicle and provide a privacy curtain for when someone uses the bathroom.