Can you use bleach in a pressure washer?

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When you purchase a pressure washer you have a wide variety of jobs floating around in your head that this amazing machine is going to tackle. For me, I was going to sort out those dirty cars, no longer paying a sponge jockey to wash them for me.

I was going to tackle the driveway and concrete areas of the garden, they had become one with mold and algae, and I did, except the pressure washer while it did a great job, struggled with the mold, it quickly came back.

The reason for this is because mold is a living organism, and we need to kill it, our pressure washer did a good job at attacking it, but we need something to give that final blow, add the nail to the coffin. Bleach, we need bleach. Bleach kills mold.

I use a diluted bleach spray around my window frames where mold starts to grow in the condensation, so surely I can use bleach in a pressure washer to kill off the filth that’s affecting my concrete, right?

While bleach is a fantastic mold remover, you should never use bleach in a pressure washer. The bleach solution will break down the rubber o-rings and other rubber components within your pressure washer, meaning costly repair bills.

But using a bleach solution is still doable.

Even if your walls are as dirty and grimy as they could possibly be, just stop. Putting bleach in your pressure washer isn’t a good idea. You will basically give your pressure washer a death sentence.

Can You Use Bleach In A Pressure Washer?

ready diy can you use bleach in a pressure washer question

If you were hoping to shoot out pure bleach through a pressure washer, yeah, think again, this will, as I mentioned above, corrode the pressure washer and will render it useless very quickly. Plus, using bleach will render your warranty void.

The ideal cleaning solution for a pressure washer is water, pure, clean water. It works well on all surfaces and will do a fantastic job are removing most washable stains. Should you decide that you are using your washer with bleach, then you will need to use a very dilute solution, but I suspect damage will still occur.

Is It Possible To Use A Bleach Mix While Pressure Washing?

If you are desperate to remove mold and mildew, then bleach is your best friend, but it’s not your pressure washer’s best friend. I get the logical reasoning; the cleaning power of bleach, paired with the cleaning power of your pressure washer, must equal. ULTIMATE POWER!!!

Look, in most cases, you aren’t going to need bleach. The high-pressure water along is enough to clean a concrete wall or the siding on your house. Adding bleach can be overkill also. Bleach will kill your plants and possibly stain the siding of your home.

There are also materials that really don’t like bleach and should never be washed with bleach. For example, if you are cleanings wood, bleach may be harmful to the varnish and can even cause your wood to dry out, crack and become unsightly.

When Would Using Bleach With A Pressure Washer Make Sense?

can you use bleach in a pressure washer moss covered path

While most will consider it overkill, there are some situations where power washing with bleach actually makes sense; these situations include:

Deep Mold Treatments – If the area you are going to be power washing has been attacked by mold, well, then water isn’t going to cut it. While water may remove the visible signs of mold, it won’t prevent it from regrowing. Bleach will kill mold, which makes it a good option to consider. Though there are other cleaning solutions you can use which aren’t bleach-based.

Moss Treatments – Very much like mold, moss can and will grow on the side of buildings, walls, and even in your tarmac/asphalt. Power washing will work to remove it, but if you leave even the faintest layer behind after you’ve power washer it off, well, it will come back. The only way to prevent it is to apply bleach or a biocide.

Biohazard Treatments – If you need to pressure wash an area that has been exposed to germs or bodily fluids well, power washing alone won’t be enough. I suggest protective gear and a mixture of water and bleach. There are other anti-bacterial cleaners you can use as well. This is the only safe way to sanitize the area.

Heavy Discoloration – Surfaces can become discolored when you don’t pressure washing them regularly. A typical cleaning session from your pressure washer is enough to remove most discoloration. Though some surfaces can be permanently discolored after suffering years of neglect. If you’ve tried your pressure washer with no success, then perhaps bleach might be the best choice.

Could Regular Pressure Washing With Bleach Hurt More Than It Helps?

This will depend entirely on the surface you are trying to wash. If you are bleaching down a driveway or stone wall, then adding more bleach won’t hurt, and doing so regularly won’t hurt either.

Other surfaces, such as marble and wood, don’t handle bleach well at all. Depending on how much bleach these surfaces are exposed to, you could potentially reduce their lifespan. Should you clean these surfaced with bleach, I would suggest applying a protective coating immediately after you’ve washed them.

Will Pressure Washing With Bleach Void My Warranty?

If your pressure washer is still under warranty, then you want to make sure that you don’t add any bleach into the water supply that goes through the internals. The majority, if not all power washer warranties, will be voided if you use anything other than water or approved soap and other chemical cleaners.

If you are worried about your pressure washers warranty, then read and see what can void it, then use soap or detergent that’s designed for a pressure washer, making sure that you mix the chemical solution with the correct parts water to hit the desired dilution, using these neat can also cause damage and void warranties.

How To Pressure Wash Using Bleach

If you absolutely must, then I suggest getting protection for your eyes and that you use a pressure washer lance that’s angled away from you, perhaps a 30-degree bend, to reduces spray back.

  1. Add four parts water to one part bleach. This assumes that you will be using a 5 – 6 percent bleach mix. If you’re using a three percent mix, you can stick to a three to one ratio. Mix this into a bucket.
  2. Place the bucket of bleach solution, and prepare your hose. You want to make sure that there are no jams or gunk in your hose or filters. If you notice any jams or residue in your hose, clean it out completely before you start washing.
  3. Place the filter part of your siphon hose into the bleach bucket and attach your hose and spray lance to your pressure washer.
  4. When putting together the rest of your pressure washer, use a black soap tip on your lance. The black soap nozzle tends to work best with cleaning solutions, and in some cases, it’s the only way to engage the detergent siphon.
  5. Keep the pressure on low. The pressure from the washer will work to mix the bleach solution, giving you a consistent solution that will evenly coat the surface of your cleaning area.
  6. Once you’re done, clean out your pressure washer by switching to a pure water bucket. This helps remove bleach that could potentially harm your washer.

While the last step rinses out the pump, I still suggest not doing the above. If you MUST use bleach, mix the solution and put it into a spray bottle and manually spray the area, let it dwell, and then rinse with your pressure washer.

When Should You Ask For A Professional’s Advice?

when to ask for a professionals help pressure washing beach cleaner

Honestly? If you are considering using bleach on a surface, take a step back and consider getting a professional’s advice. Bleach is extremely caustic and will wreak havoc on surfaces such as wood or marble. It’s awful for the environment.

Talk to an expert, and they’ll tell you to seek professional advice before pressure washing a surface with harmful chemicals. You won’t want to start the process, only to find that it causes damage that can’t be reversed. That’s a costly mistake to make.

Wrap Up

Hopefully, you’ve picked up that I don’t think that you should use bleach. There are many other chemical solutions on the market that you can use. There are many different detergent and soap mixes designed for pressure washers.

Not only are they designed for use in a pressure washer, but they can also be environmentally friendly while still removing algae and moss. These green detergents are what I go for. They are safe for your home, the environment and can be used safely with little worry about the lasting effects on your plants and pets.

Plus, these solutions can be specially designed for cleaning your deck, removing all that engrained dirt without causing damage.

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