How To Prevent Freezing of Portable Toilets

Can toilets freeze?

Few people enjoy the idea of using a porta-potty during the cold winter months. The chilly temperatures combined with the uncomfortable level of exposure make for an unpredictable experience, but you can make the experience more comfortable by learning how to prevent the freezing of portable toilets.

Since portable toilets remain exposed to outdoor elements, many people have to answer nature’s call while combating nature’s forces. Porta-potty water is subject to freezing over. Even more modernized portable restrooms risk frozen plumbing.

However, below-freezing temperatures don’t stop construction work, renovations, and other events that put regular restrooms temporarily out of commission. So, how do you keep a toilet from freezing outside? Below, our team at Wilkinson Portables gives you the scoop. 

Why You Should Learn How to Keep Toilets from Freezing

If you already know how porta potties work, then you know that they are sanitary, durable facilities that can handle all types of weather. However, a portable toilet with frozen water can’t do its job as well.

What happens when a portable toilet freezes? When technicians encounter frozen toilets, they can’t empty the waste chambers as needed. A frozen potty usually means that all of its contents have frozen solid, including numbers one and two.

As a result, the technician will have to wait until temperatures rise enough to thaw the contents. So you’ll have an outdoor toilet that’s out of commission for the foreseeable future. Fortunately, most portable toilet water contains a solution that prevents freezing unless the temperatures dip extremely low.

Porta-potty water doesn’t freeze easily. It contains chemicals that prevent ice from forming. However, certain temperatures can still cause a portable toilet to freeze without some winterizing ingredients.

If your weather forecast predicts these extreme temperatures, you should take proactive measures to learn how to keep an outdoor toilet from freezing. After using the right amount of antifreeze solutions, you’ll easily maintain usable, winterized portable toilets until the weather warms up again. 

How to Keep an Outdoor Toilet From Freezing

To learn how to keep a toilet from freezing outdoors, purchase the substances listed below that prevent water from freezing. Add the recommended amounts straight into the water or combine them for an effective mixture. 

Rock Salt

Rock salt provides an inexpensive and readily available solution to prevent your portable toilet from freezing. You should use two pounds of rock salt for every gallon of liquid in the tank to achieve optimal protection. This proactive solution will keep you covered throughout the winter.

Rock salt works best for portable toilets in southern regions. It doesn’t work effectively for areas where temperatures regularly dip below zero degrees. If your local forecast regularly predicts lower temperatures, you’ll need a stronger solution to prevent the toilet from freezing.  

Magnesium Chloride

While magnesium chloride costs more than rock salt, it works effectively until temperatures reach minus 26 degrees Fahrenheit. You can choose a crystal or liquid composition to add to your tank. Add 2.25 pounds of magnesium chloride for every gallon of water in your toilet’s tank to achieve optimal results.

Remember to mix the combination well to ensure even distribution. The mixing process can present a challenge. Some portable toilet renters or owners prefer that a professional technician tackle the process. 


Unlike magnesium chloride, methanol is only effective at temperatures above minus 9 degrees. However, you don’t have to mix it thoroughly to get the prevention you need. Still, methanol requires precise measurements if you want to avoid creating a flammable substance.

A flammable porta potty presents a unique and smelly danger to anyone in the facility. First, calculate how many gallons your portable toilet holds before adding the methanol. Then, add enough methanol to account for 33% of the tank’s liquid contents.

Ensure you schedule a technician to pump the contents as soon as the temperatures rise above freezing. The fumes created by water, excrement, and methanol can present a health hazard with long-term exposure. 


If you can’t purchase the above ingredients in time, you’ll inevitably end up with a frozen outdoor toilet in your hands. Your next option is to call a technician to pick up your frozen porta potty and replace it with a fresh one. Some services can also switch out your water tank with a fresh one for a simpler process.  

How to Prevent Portable Toilets From Freezing

What if you have portable facilities that have running water and flush? Do you know how to keep these toilets from freezing? Fortunately, experts have a tried and true method to prevent frozen tanks.

Luxury portable restrooms, campers, and RVs often have flushing portable toilets. If you’ve ever wondered whether the same process applies, learn more below.

Porta Potty Antifreeze 

Ready to learn how to prevent the freezing of portable toilets? First, purchase the ingredients for porta potty antifreeze. This mixture requires rock salts and antifreeze. Follow the instructions below. 

Step 1

Calculate how many gallons your water tank currently holds. You’ll need a cup of antifreeze for every five gallons of water. You should also have a cup of rock salt.  

Step 2

Flush the measured amount of antifreeze down the toilet. It will travel through the pipes and into the holding tank. This helps protect most components of your portable plumbing system. 

Step 3

After flushing all the antifreeze into the holding tank, pour a cup of rock salts into the toilet. Flush the salt. It will mix with the antifreeze in the holding tank. 

Step 4

Allow any faucets to drip for extra protection. Your portable toilet with running water should remain safe from cold temperatures and frozen contents. 

Choose Wilkinson’s Portables for Professional Porta Potty Solutions

By implementing these methods, you’ll quickly discover how to prevent the freezing of portable toilets.

At Wilkinson’s Portables, we are a trusted supplier of high-quality porta potties serving El Dorado County, Folsom, Plymouth, and Placerville. When you need reliable porta potties to keep your outdoor event or worksite sanitary, call us at (530) 531-8295 to learn more about our competitive pricing, comprehensive knowledge, and other services

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