When your event season ends or a construction project wraps up, it is easy to forget about your portable restroom units. However, storing them properly during the off-season is key to extending their lifespan, preventing damage, and reducing unnecessary maintenance costs later on.

This guide covers step-by-step instructions to help you store your portable restroom the right way, clean, dry, and protected.

Drain waste and water tanks completely

Watch out for your water tank and waste tank

Before storing your unit, make sure to empty all tanks. This includes both the waste tank and the clean water tank, which can hold up to 100 gallons, depending on the unit model.

Use the appropriate equipment and follow EPA-approved procedures to safely dispose of any remaining waste. Rinse the waste tank thoroughly with fresh water and disinfect it with a biodegradable chemical treatment.

Draining both tanks eliminates odors and prevents the growth of bacteria and mold during storage. It also protects the plumbing system and seals from freezing or cracking in cold weather.

Clean and dry all surfaces thoroughly

Check the system and types of items and furniture of the portable restroom

Once the tanks are empty, deep clean every part of the interior. Pay attention to:

• Toilet and urinal surfaces
• Hand-held bidet (if included)
• Handwashing sink
• Trash bin
• Floor and walls
• Ventilation fans and sensor lights

Use non-abrasive, eco-friendly cleaning products. Wipe down all surfaces and allow the interior to dry fully before closing the unit. Any leftover moisture can lead to mildew, mold, or corrosion, especially in units with solar-powered electrical components or motion-activated lighting.

Lock doors and secure the unit

Lock the restroom carefully to avoid break-ins.

To prevent unauthorized use, vandalism, or animal intrusion, always lock the doors of the unit during storage. If the unit will be left outdoors, use an additional padlock or a heavy-duty chain to secure it to a fixed object.

Note the unit’s VIN (Vehicle Identification Number), which is important for tracking, maintenance, and inventory records. You should also take photos of the unit’s condition before storing it and log this information for future reference.

Store in a cool, shaded, and dry area

Store in shaded places; avoid direct exposure to weather.

Exposure to extreme sun, wind, or moisture can weaken materials over time. If possible, store the restroom in a shaded area such as a garage, covered shed, or indoor warehouse. This helps preserve the plastic surfaces, electrical systems, and rubber seals.

If outdoor storage is the only option, place the unit on a level surface and cover it with a weather-resistant tarp. Make sure ventilation openings remain clear to prevent moisture buildup inside.

Units equipped with solar panels or battery-powered lights should be turned off or disconnected during long-term storage to preserve battery life.

Protect against pests and insects

Be careful of insects and their ability to destroy your portable restroom

Rodents, ants, and other insects are drawn to dark and enclosed spaces. To keep them out:

• Seal or cover any ventilation openings
• Close the toilet lid and all access panels
• Remove any leftover trash or organic material inside
• Use safe pest deterrents like essential oil sachets or ultrasonic devices

Inspect areas around the doors and floor for cracks or gaps and seal them if needed. A few simple steps can prevent major infestations and damage.

Perform periodic checkups.

Check regularly; 2 to 4 weeks is the best time

Even when not in use, your unit needs occasional attention. Schedule a checkup every 4 to 6 weeks to look for:

• Signs of water leaks or condensation
• Pest activity
• Structural damage or cracks
• Condition of the solar panel (if applicable)
• Door locks and security

If the unit is stored outside, check the tarp or covering to ensure it remains waterproof and properly secured.

Maintaining a written log of inspections helps you stay organized and ensures nothing gets overlooked.

Bonus: prepare for quick reuse

Taking good care of your portable restroom is taking good care of your monthly cash flow and profitability.

When the off-season ends and it is time to use the unit again, you will be glad you stored it correctly. A properly stored restroom will need minimal prep work, just a fresh rinse, refilling of water and chemical supplies, and a quick functionality check.

Make sure to test lighting systems, ventilation fans, hand-held bidets, and all plumbing before deploying the unit. Also, verify that the unit still complies with EPA, DOT, and local health regulations.

Storing your portable restroom properly is not just about keeping it clean; it is about protecting your investment. A few extra steps at the end of your project or event season can save you time, money, and hassle when you need the unit again.

Whether your restroom is equipped with modern features like solar-powered lights, motion sensors, or baby changing stations, these best practices will help preserve every component during the off-season.

Treat your portable restroom with the same care as any other professional equipment, and it will be ready to serve at full capacity again when the time comes.