Can You Use Bleach to Pressure Wash a House?

It is not recommended by manufacturers to use bleach in a pressure washer as it can permanently damage the machine. However, you can directly spray bleach onto a house to get rid of mold or mildew. Detergents are safe and effective to use with most pressure washers.

You’re doing some yard work for spring cleaning and decide that the outside of the house could use a little TLC. You might even notice some mold or mildew growing which can cause damage if left for too long. You haul out a pressure washer and are ready to get to work, but are wondering if you should use bleach?

There are plenty of ways to help you get the best results from your pressure washer and get your house sparkling. Keep reading for how to best use bleach and pressure washing to give you the cleanest house on the block!

Man using bleach in pressure washer to clean a portacabin

Related Reading: Does Pressure Washing with Bleach Kill Grass?

How To Use Bleach to Wash A House

Pouring bleach directly into a pressure washer can damage it which is why you want to avoid this. However, it is still safe to use bleach in a regular spray bottle to give your house that extra shine.

Water pressure alone will not get rid of exteriors that are plagued by moss or mildew. While you can try detergents or soap, bleach is one of the most effective chemicals for stopping the additional growth of the plants. The best strategy would be to use a spray bottle to directly spray bleach on these areas if they are reachable.

If the mold or mildew-infested areas are not safe to reach with a spray bottle, you can attempt to use a bit of bleach in the pressure washer. However, be aware this is not recommended by the manufacturers and most companies void the warranty if you use bleach. 

If you do want to risk using bleach in your power washer, mix 1 part bleach with 4 parts water to dilute it and reduce possible machine damage. Clean the machine with pure water afterward so that no bleach residue is left sitting which could cause corrosion.

Tips For Using A Pressure Washer

Choose The Correct Power Washer

If you’re borrowing a power washer from a friend, you might not have many options. But keep in mind different house exteriors require different treatments. Vinyl siding which is usually on more modern houses does best with the more powerful washers. Stucco and aluminum houses might be damaged by excessive pressure and so you want to look for a lower pressure machine. All power washers have different settings. Start low and you can increase power if you feel that you won’t cause damage.

Related Reading: 11 Pressure Washer Safety Tips You Should Know

Prepare The Exterior

You’ve got the right power washer and are eager to get cleaning. Just like painting or cooking, it’s important to prep everything first. To avoid accidentally damaging anything, make sure you cover up house accessories such as outdoor lights, electrical sockets, or external AC units. Be extra careful that your windows are closed and locked up! On that note, make sure there are no open cracks that water could leak into and cause damage, especially around basements where important equipment may be.

Strategize Your Cleaning Method

There are different ways that you can go about actually power washing, but the most important thing is to have a strategy so that you don’t miss a spot. Most pressure washer manufactures recommend going horizontally with the hose for the best results.

Some people prefer starting from to the top of the house and working their way down to the bottom. This method can save a bit of water and detergent as the run-down will start to clean the below areas. Other people prefer to go bottom to top so they can make sure everything is fully clean and they don’t miss anything.

Decide What Detergent To Use

If your house has some light dirt and grime and just needs a little polishing, you will probably be fine with a lighter washing with just water. The high power of the pressure washer is specifically designed so that no additional soap, detergent, or chemical is needed. Just the power of high-pressured water!

That being said, if you have heavier dirt, including mold and mildew, you’re may want to consider using a detergent. The chemicals will help dig in and get the exterior properly cleaned.

In a pinch, you can actually use regular laundry detergent or dish soap with pressure washers. They are safe and effective both in the machine and on the external siding of the house.

However, if you’re looking for some really great results with the best tools, you should check out the following. They really do work and are top-rated by customers on Amazon!

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Again, if you’re in a pinch there is sure to be something around your home you can use. However, the above is specifically designed to be tough on dirt, grease, and mold while protecting your exterior materials and paint.

Let The House Fully Dry

You might be surprised to hear that it can take two full days for houses to fully dry after a power washing session. If you’re pressure washing in preparation for painting be sure to keep this in mind. You’ll want to make sure the house is fully dry before attempting any painting or decorating.

Related Reading: Should You Wear A Mask While Pressure Washing?


If you want to add some curb appeal to your home, pressure washing is a surefire way to do so. Depending on your needs, you can decide whether it is worth it to risk it with bleach, try some detergent, or keep it safe with pure water. With the right tools, preparation, and hard work you are guaranteed to make your house look brand new!