Temporary Large Scale Portable Restroom

Have you ever been to an outdoor concert, camping festival, or major event and thought, "There has to be a better bathroom solution"?

This project is a large, connected portable porta potty system designed to ride on top of a semi-truck trailer. It provides many private stalls in a compact and mobile package and it is perfect for temporary deployment at large outdoor venues.

This design can help solve long wait lines, improve cleanliness, and offer a much better overall experience for outdoor eventgoers. It's is also built with easy setup and takedown in mind!

In this Instructable, I'll walk you through the basic idea, planning, and construction steps for building this unit.

Plywood or durable plastic panels (walls, floors, doors)

Aluminum framing for lightweight structure

Water tanks (freshwater + greywater)

Plumbing and piping (toilets, venting, water lines)

Portable waste storage tanks (if not using direct connections)

Truck trailer or flatbed platform

Hinges, latches, door handles

Waterproof sealant

Weatherproof paint or coating

Vent fans (optional, battery/solar-powered)

Non-slip flooring material

CAD software (for design tweaks)

Advanced construction tools (Plastic injection molding, CNC machines, metal press machine)

Create a modular design that fits on a standard semi-trailer (~48–53 ft long, 8–8.5 ft wide).

Design individual stalls with walls and doors for privacy.

Include space for freshwater and waste storage if hooking up isn't available.

Create CAD models to refine stall layout, roof slope for rain runoff, and material thickness.

Build the main structure using lightweight aluminum framing.

Weld or bolt a rectangular base frame to match the dimensions of the truck trailer.

Add vertical supports for each stall and roof beams across the top.

Ensure the frame is strong enough to resist flexing during transport.

Focus front of design with aerodynamic frame design

Cut wall and roof panels from weather-resistant plywood or composite board.

Pre-drill holes and attach panels to the frame with rivets or bolts.

Seal edges with waterproof tape or caulking to prevent leaks.

Paint or coat panels with outdoor-grade waterproof sealant.

Weather-resistant materials for each door

Mount doors with stainless steel hinges; add inside slide latches

Extend roof panels 6–12 inches forward to create a protective overhang

Seal all joints to ensure durability during transport and outdoor use

Install toilet units in each stall (gravity flush, chemical toilets, or vacuum systems).

Run freshwater and greywater lines to tanks or hookup ports.

Install small vent pipes for each stall to reduce odors.

If possible, add solar-powered ventilation fans on the roof.

Add solar panels to power ventilation fans or LED stall lights

Install handwashing stations with foot-pump sinks and soap dispensers

Use a fold-out ramp for ADA accessibility compliance

Attach aerodynamic rear panels to reduce drag during highway transport on the semi trailer

Use quick-latch mechanisms for faster assembly and disassembly on-site