Wiki Tips and advice Philippines - English

How to Clean Concrete

Whether you want to remove dirt and debris from the driveway, or blast away oil stains – find out how to clean concrete with this how-to guide.

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how to use a pressure washer

Concrete is both durable and versatile, making it the perfect material for external surfaces and flooring. However, it is naturally porous, which also means it is a magnet for mud, dirt, and hard-to-remove stains.

If you’re wondering how to clean your concrete and any stains it may hold – this guide will tell you all you need to know!

  1. First, remove any loose material with a brush. This will make the next step easier and prevent the pressure washer from turning debris into a potentially hazardous missile.

  2. Wash the area with a product like . This is useful even if the only contaminants are mud and soil, since these are usually bound by some amount of oil or grease.

  3. Wait for 10–20 minutes (our favourite bit) then rinse with a hose.

  4. Test out your pressure washer on a small area to get a sense of its pressure. The right pressure will vary depending on the concrete ­– looser concrete will demand a lower one. Remember: We’re trying to wash concrete, not blast bits off it!

  5. Take your pressure washer and make broad, wide sweeping motions across the concrete. Direct the flow at a low angle of 30° if you’re cleaning concrete-joined blocks, so as not to damage the jointing. 

As with all cement-based substances, concrete is naturally alkaline. Washing concrete with acid-based cleaners can therefore cause damage unless neutralized. Avoid this by cleaning concrete with alkaline products, such as . These are just as effective at removing stains but gentler on your concrete.

Concrete Cleaning Tips: Choosing Your Pressure Washer

Like a lot of appliances, pressure washers come in a great array of types and sizes – not all of which will be right for the job. Many manufacturers or renters tout the maximum pressure of their machine, but this is far from the be-all and end-all. 20 MPa should be easily enough for most tasks and increasing pressure beyond what’s sufficient does little other than increase the risk of damage. Instead, the most important factor is flow rate – with adequate pressure secured, a greater flow rate means a faster clean.

Likewise, it’s advisable to use a fan nozzle rather than a jet. The fan sweeps out a greater area, making it easier to get an even final color, and makes for faster work too. It’s also easier to accidentally damage your concrete with the greater pressure of the jet, so there’s little advantage to using it.

If, however, you are struggling to find a washer with enough pressure, you can buy a rotating nozzle to boost the effective pressure of the water. These achieve the same effect as a fan nozzle but without deflecting the water, so that no momentum is lost.

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Safety warning: 20 MPa is a lot (more than twice the pressure of a stiletto heel). So handle the washer with care, wear eye protection, and always follow the manufacturer’s instructions carefully! Learn how to use a pressure washer safely in this article

How to Remove Stains from Concrete

If there’s an especially heavy oil or grease stain – as can so easily happen if you own a car or other vehicle – then take some clean cat litter or fine sawdust and cover the stain with it before washing. Then, leave it overnight. This takes some time, but the cat litter should draw the worst of the oil up out of the concrete, ready for it to be brushed away.

Learn to clean other outdoor materials and areas of your home in the Out of Home section on Wiki Tips English! From gutters to windows, cars to BBQs, we've got you covered.

  • Absorb the worst of any oil or grease stains.

  • Select your pressure washer wisely.

  • Wash floor with a detergent, then use a pressure washer.

Do you want to learn which household cleaning tasks cause the most stress?  Then read our Heated Household data analysis. 

Frequently asked questions on cleaning concrete

Cleaning concrete with acid - what should I know?

First things first, whenever cleaning concrete with acid, make sure you do so safely. Concrete is alkaline, so acid isn't always the best idea when it comes to cleaning, but it does have its uses when used with care. If you mix one-part muriatic acid with ten-parts water, you can add this solution to a spray bottle and brush it onto your concrete. Leave it to work for 10 minutes before spraying the entire surface with a mix of one cup ammonia and one gallon of water. Make sure you fully cover all areas where you used the acid wash to neutralize the acid and prevent it damaging your concrete.

How do you disinfect concrete?

If you're looking for steps for how to disinfect concrete, we recommend mixing up a disinfectant made of 2 cups of bleach in one gallon of water. Cover the surface of your concrete in the mixture, leave it for 15 minutes before rinsing the concrete with clean water.

How do you get dried concrete out of clothes?

Here are some easy tips and tricks for how to get dried concrete out of clothes. If you are working with dried concrete dust, you should avoid getting it wet and simply use a stiff brush to remove it from your clothing. If you have wet concrete that has dried in place on your clothing, the best way to remove it is to first break away any loose chunks you can. Then soak the stain in white vinegar. This should break down the concrete, allowing you to rub it away using a soft brush such as a toothbrush. Finally, run your clothing through the washing machine with the normal amount of laundry detergent, adding 1 cup of white vinegar to the drum with your clothing. All that is left to do is air dry your clothing and wear it again.

How do you remove alkaline from concrete?

Alkaline deposits can cause efflorescence (the white substance you may have noticed on your concrete) so it's important to know how to remove alkaline from concrete. First, wet the area you wish to remove the alkaline deposit from using a sponge and clean water. Next, mix a solution of equal parts water and white vinegar. Use a soft brush and your DIY cleaning solution to scrub away the deposit. Rinse the area with clean water and allow it to dry fully. To prevent further deposits appearing, we recommend you seal the concrete with a masonry sealant.

How do you remove cement from car?

The steps for how to remove cement from a car start with a key piece of advice – always work with care, lifting just a little at a time. Start by using masking tape to protect the areas of your car around the concrete. Mix a solution of equal parts white vinegar and water and spray it over the concrete. Ensure that you thoroughly soak the concrete, and as it begins to work, use a wooden or plastic spatula to gently chip away the concrete layer by layer. Continue to spray and chip away until there is only a thin layer remaining. At this point we recommend using a clay bar to remove the last remaining residue from the surface of your car.

Originally published