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How to Fix Pressure Washer Marks in Cement

A pressure washer is a handy piece of equipment that can serve multiple purposes for homeowners. Ranging from washing your driveway or car to debarking wooden logs to even fixing pressure washer marks in cement, pressure washers do the job for you. In this blog post, I will discuss a method to fix pressure washer marks in cement.

To fix pressure washer marks in cement, try spraying on some muriatic acid and scrubbing it quickly. Then pressure wash with a fan nozzle. A solution of muriatic acid will etch the cement and camouflage the marks.

When the cement surface on your driveway starts collecting antifreeze stains, dust, dirt, debris, dry twigs, gum, grime, grease, spilled drinks, mold, mildew, mud, oil, and pet urine, it becomes noticeable in an unpleasant way. There is a need to pressure wash it. When a novice uses a pressure washer, he/she may leave deep marks in the cement as the top layer of the cement also gets washed away.

“You may be inclined to pressure wash just about everything around your house, but it is not always a great idea,” said Dave Trezza, the test engineer who oversees pressure washer testing for Consumer Reports. “The supercharged stream of water can damage the paint and nick or etch the wood and even certain types of stone.”

Fortunately, there is an effective method for fixing the tiger stripe marks caused by a pressure washer in cement. For these marks, muriatic acid is the solution. Muriatic acid is also known as hydrochloric acid.

How to acid wash cement?

Acid washing is also called acid etching. To fix pressure washer marks in cement, brush, or vacuum dust from the cement. Remove the oil stains with an alkali detergent or degreaser.

But don’t use TSP cleaner (Trisodium Phosphate). It can violently react with muriatic acid and release harmful gases. Rinse the cement with water.

It is better to use hydrochloric acid, or muriatic acid (a less-pure variant of hydrochloric acid), but remember that these products are very dangerous as they produce poisonous fumes. It can be used outdoors only. You must observe the necessary safety precautions before planning to fix the marks in cement.

You can find muriatic acid here. If you do not feel comfortable with these products you can also ask a professional.

Use a pair of acid-resistant gloves, a pair of rubber boots, a respirator with an acid-grade filter, a face shield, a Butyl or PVC apron, and vapor-proof goggles. Make sure the area you are cleaning in is airy for proper ventilation. Keep some baking soda or garden lime at an arm’s length to neutralize the unnecessary spills.

Always use a plastic bucket or a watering can to dilute the muriatic acid. Pour the water first, then slowly add the acid. Most plastics, unlike metals, are resistant to the damage caused by muriatic acid.

Mix three to four parts of water with one part of acid for ten to fifteen percent concentration. Wet the entire area. Spray the water on the cement until it is fully damp but not puddling.

Remember that one gallon of muriatic acid can fix the pressure washer marks on an area of forty-five square feet. Right after pouring on the acid solution, brush the cement using a long masonry brush or a push brush. Make sure the cement doesn’t dry out when you are pouring the acid.

Keep the garden hose handy. Wait for at least ten minutes for the muriatic acid solution to fully etch the cement. Scrub off any residue with a big brush before the acid dries. Keep rinsing with plenty of water.

Add one cup of ammonia, baking soda, and garden lime to one gallon of water. Scrub it over your cement, particularly in the corners, and let it sit for at least ten minutes. Any liquid left on the surface of your cement will leave white stains after drying out.

Spray the cement with plenty of water and repeat several times. Finally, rinse the water with a brush or vacuum and a hose. Never use a pressure washer to rinse the acid, as it will drive the acid deep into the cement.

Use a pH test strip to check the final rinse water. If the result is below six, it means there is a lot of acid on the cement yet, but if the result is above nine, it means there is a lot of basic neutralizers. Rinse again. You can find pH test strips here.

Never store the leftover muriatic acid solution for future use. Pour it into a plastic bucket, slowly filled halfway with a base neutralizing solution. Now add more acid and base slowly until the solution stops fizzing.

After this mixture gets fully neutralized pour it down the drain or sink. Dispose of the rest of the acid in the same way. Muriatic acid left in storage is a serious hazard.

Frequently Asked Questions (FAQs):

● What is a commercial pressure washer?

Commercial pressure washing uses high-pressure water spray to remove algae, dust, dirt, grime, grease, chewing gum, fungus, mud, mold, and loose paint. A commercial pressure washer is an automated tool consisting of two or four high-pressure jets on a rotating bar that swivels when the water flows. This action creates a uniform cleaning pattern that can clear flat or curved surfaces at a rapid speed.

The regular use of a pressure washer reduces allergy agents, asthma agents, bacteria and improves aesthetics. It is suitable for indoor and outdoor use on areas like your aisle, attic, balcony, cladding, driveway, deck, gutter, fence, roof, patio, sidewalk, lawn, or parking lot. You can find a professional pressure washer here.

● Can I pressure wash my roof?

No, don’t pressure wash your roof as it is very dangerous and potentially damaging. If you are a novice, using a pressure washer will cause a blowback which will throw you off the ladder while you are perched on it. The strong stream of water will loosen the asphalt shingles of your roof.

It will stripe off the embedded granules, which extend the life of the roof. It is safe to spray on a cleaner that will kill moss and mold. You can also use a pump sprayer filled with a mixture of bleach and water to let the moss die on its own.

First, build-up the pressure in the pump sprayer, then climb the ladder. Make sure your roof gets maximum sunlight as this will prevent moss growth.

● Is it safe to pressure wash a wooden deck?

Yes, a wooden deck can hold up to the pressure just fine. Camaru, Ipe, Tigerwood, yellow pine, and other South American hardwoods can handle the pressure just fine. If you don’t hold the nozzle too close, the decks made out of pressure-treated wood will be okay.

To make sure the spray is not marking or etching the wood, always start with a low-pressure nozzle. Always work along the length of your board to go with the grain of the wood. Read your owner’s manual to know the manufacturer’s recommendations about the distance you need to maintain between your nozzle and the surface of your deck and learn about the nozzle settings.

● Is it safe to pressure wash the cement driveway or walkway?

No, cement cannot withstand high-pressure cleaning. Only a lower pressure nozzle is safe for moldy or mildew-covered cement. But never use a zero-degree tip as it will leave deep visible marks in the cement of your driveway or walkway. You can find pressure washer nozzle tips here.

● Is it safe to pressure wash a siding?

Sometimes, a vinyl siding can withstand pressure washing, and cement siding cannot. An aluminum siding will dent upon pressure washing. Wood clapboard siding can withstand pressure washing.

Always start on the lowest pressure setting with a broad nozzle. You can use more concentrated blasts only for stubborn marks. Never pressure wash shingle siding, as the shingles will get knocked off.

When pressure washing your siding, prevent the water from getting trapped between the sheathing and the siding, as it will promote mold growth. Never let the water get into the open gaps on siding runs. Replace or repair the damaged, loose or missing siding before pressure washing.

● How many types of nozzle tips are there in a pressure washer?

Pressure washers come equipped with either an all-in-one variable spray wand which lets you adjust water pressure with a twist or a set of interchangeable nozzles.

Five different nozzles include:

  1. The red nozzle is the most powerful, concentrated nozzle setting.
  2. The yellow nozzle is used for heavy-duty cleaning.
  3. The green nozzle is used for general cleaning.
  4. The white nozzle is used for vehicles, patio furniture, boats, and easily damaged surfaces.
  5. The black nozzle is a low-pressure nozzle used to apply soap and other cleaning agents.

You can find pressure washer nozzle tips here.

Final Remarks

To conclude this response post, I would say that you can use muriatic acid or hydrochloric acid to fix the pressure washer marks in cement. Make sure you observe all the necessary safety precautions and use it outdoors to avoid inhaling the harmful fumes that it gives out. Always seek the assistance of professionals to get your cement surface pressure washed.

Proper training and experience are necessary to operate a pressure washer; otherwise, you will badly damage your cement or concrete surfaces.