If you’ve got a stubborn stain on your garage floor or patio that you just can’t shift with regular water and your pressure washer, you may need some extra help in the form of a detergent or chemical. So, what are the chemicals for pressure washing, and should you be using them at home, without the help and expertise of a professional service?
Detergents and chemicals can remove more stains and marks from concrete, stainless steel, glass, and masonry than water alone. They can also speed up the time you spend on the job. However, there are some precautions you need to take before choosing a detergent or chemicals to help you out.
Using the wrong chemical or detergent can damage your car, home, or decking. Using the incorrect ratio of chemicals to water can be downright dangerous to you and the surrounding environment. You’ll need to ensure you select detergent chemicals that are specifically designed for use with the best pressure washers (opens in new tab).
We’ve talked to a gardening and home maintenance expert for their take on pressure washing with chemicals at home, and taken a look at some of the most commonly used chemicals and detergents, and what they’re best used for.
What are the chemicals for pressure washing?
Jenkins recommends these key safety tips, "The safest way to use chemicals with your pressure washer is to apply the chemicals manually to the area beforehand. Allow the chemical to settle for a few minutes, and then spray it away with your pressure washer. When using any harsh chemicals, it’s important to wear the appropriate safety gear. Wear protective clothing, gloves, and eye protection."
When pressure washing with simple water doesn’t shift dirt, grease, or grime, the following chemicals may help.
Detergents designed for use with pressure washers are widely available. They can come ready-made, so can just be added to your pressure washer’s tank, or as concentrated solutions. If they’re concentrated, be sure to read the instructions carefully for the ratio of detergent to water that’s required.
If you don’t have a tank fitted to your pressure washer, pop its detergent hose into a bucket containing the detergent instead. Or you can use a foamer or soap shooter. Soap shooters sit on the end of your hose and shoot out the detergent into the pressurized water stream, while you spray foamers directly into the surface you’re cleaning.
Depending on the job at hand you can purchase one of the following:
Concrete detergents: These can help remove oil from your driveway or garage floor.
Vehicle detergents: Use these on your car, motorcycle, or even your boat - but be aware that each one will contain different ingredients to remove specific dirt. So a boat detergent won’t do the same job as a car detergent, and may even harm your car’s paintwork.
Home cleaning detergents: Used for cleaning exterior wall sidings to remove dirt, grime, and dust.
Wood detergents: Used for decking, fences, and wooden gates to remove mold, mildew, and moss.
We recommend looking for detergents that are biodegradable. This means they can be safely washed away down drains without causing any damage to the environment.
2. Oxalic acid
Oxalic acid can help to remove hard water marks and rust stains from concrete, but it can also be used on tiles and grout. It’s commonly used for cleaning patios, pools, and timber that’s gone gray or black from mold.
3. Citric acid
Considered safe for most residential cleaning jobs, citric acid can help to remove stains and rust from patios, driveways, and decking.
Also known as sodium hydroxide, lye is an effective degreaser. This makes it suitable for glass and stainless steel.
Used sparingly, bleach can help to remove and prevent mold and mildew from growing back, sanitizing, and disinfecting areas. It can also remove stubborn stains.
Should you use chemicals for pressure washing?
We spoke to MyJobQuote (opens in new tab) gardening expert, Fiona Jenkins, to sound her out on whether people should use chemicals with their pressure washers at home. “You can use soaps and detergents with your pressure washer,” says Jenkins, “as long as you use it at low pressure. For anything else, you will need to leave the work to a professional.”
Certain chemicals, such as bleach, need to be carefully diluted in order to keep plants and wildlife safe. A professional pressure washer company will know what ratio of chemicals to the water to use, and what precautionary steps to take to avoid dangerous chemicals leaking into the environment. They’ll also know whether certain chemicals are safe to use with high-pressure washers.
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