Concrete floors, sidewalks or garages can start to wear down when rust or mold seeps into its surface. Although concrete is highly durable and relatively low maintenance, regular cleanings are an important part of proper upkeep. Whether cleaning a concrete driveway or tackling stains in a garage, using the right cleaning supplies can help concrete look its best.

Before You Start Cleaning

According to The Spruce, knowing the type of concrete finish is important to prevent damage and clean effectively.

Different types of concrete finishes:

• Sealed: Stain-resistant concrete coated with resins, silicates, epoxies or urethanes.
• Unsealed: Poured, untreated concrete that’s porous and susceptible to stains.
• Polished: Wet or dry polished concrete with a glossy finish.
• Stained: Permanently colored concrete that can be sealed or unsealed.
• Painted:  Painted concrete floors with sealed or unsealed surfaces.

Cleaning Supplies

Concrete Cleaners 

Since concrete is porous it can hold dirt, sometimes making it difficult to clean. Using the following types of concrete cleaners and degreasers can help remove different types of stains and grime:

• pH-Neutral Cleaners: Mild multi-purpose cleaners used for unsealed concrete without embedded dirt. 
• Acidic Cleaners: Acid-containing cleaners used to remove dirt, stains and contamination from concrete.
• Alkaline Degreasers: Grease, oil and stain-removing cleaners that help neutralize concrete surfaces after using acidic cleaners.
• Enzymatic Cleaners: Cleaners containing active enzymes to help remove stains and contamination. 
• Specialty Cleaners: Cleaners and degreasers designed to remove specific types of concrete stains like rust, mold and mildew.

Supplies

• Broom, dust mop, or wet/dry vacuum
• Soft non-metal scrub brush
• Microfiber cleaning pads
• Wet mop or steam mop
• Bucket
• Chemical-resistant gloves
• Optional: Garden hose, pressure washer or floor scrubber

5 Tips for Cleaning Concrete

Always clean up spills as soon as possible to prevent surface stains. Concrete cleaning methods vary depending on several factors, including the type of finish, staining, location and available supplies. The following tips provide some general guidelines for cleaning concrete. 

1. Remove Loose Dirt and Debris 

Sweep or vacuum loose dirt off the concrete. Dust or steam mopping can also help remove dirt and debris from concrete flooring. When cleaning a driveway or patio, remove and treat any weeds growing in cracks before tackling stains. 

2. Spot Treat Stains

Wet mop concrete using a pH-neutral cleaner and water. Rinse with water and allow to dry. You can also use liquid laundry detergent and water to remove stains, then scrub the area with a stiff nylon brush.

3. Let Dry & Repeat if Necessary

Allow concrete dry before allowing foot traffic or replacing rugs and furniture. If the staining remains, you can use a stronger chemical or degreasing solution, depending on the type of stain. Rinse well with a bucket or garden hose after repeating the stain treatment.

4. Pressure Wash Tough Stains

Consider using a pressure washer and detergent or cleaning solution for tough outdoor concrete stains. Always gradually increase the pressure as needed so you don’t accidentally damage the concrete. Don’t forget to wear protective equipment like safety goggles and gloves when pressure washing and protect windows, furniture and plants since the water pressure can cause damage.

5. Apply Wax or Sealer

Depending on the type of concrete, applying sealer or wax can help provide a protective coating to protect against stains, making it easier to maintain. Many concrete sealers need to be reapplied every few years. 

Removing Concrete Stains

Since concrete is absorbent, stains can settle in and harden, making them extremely difficult to remove – especially on unsealed concrete. While there’s no one way to remove stains from concrete, the key is using an effective cleaner. You can opt for commercial-grade concrete stain removers or more common household cleaners like baking soda or laundry detergent. Always test whatever cleaner you use to remove concrete stains first to ensure it doesn’t discolor the concrete. 

Grease and Oil Stains

For fresh oil and grease stains, use a rag to wipe up or sprinkle sawdust or cat litter directly onto the stain to absorb as much as possible. Once the spill is absorbed, brush away the remaining powder with a broom. If a stain remains, apply baking soda or powdered laundry detergent, then scrub the stain with a nylon brush and water. Using a concrete cleaner or degreaser can also help remove old grease and oil stains.

Rust Stains

Acid-based cleaners are often the best option for removing rust stains from concrete. You can also use natural products like white vinegar or lemon juice for light rust stains or acidic cleaners for heavy-duty stains. The concrete finish, age and severity of the stain are all factors that determine which type of cleaner to use. However, the sooner you tackle rust stains, generally, the easier they are to remove. 

Tire Marks

Degreasers can help remove tire marks from driveways and garage floors. First, spread a degreaser over the stained area. Let the cleaner work according to the manufacturer’s directions before scrubbing it with a stiff brush and rinsing well with water.

Water Stains, Mold, and Mildew

Removing mold, mildew and water stains from indoor concrete flooring differs from cleaning a concrete patio with the same issue. A hose or pressure washer can help remove mold, mildew or water stains from concrete patios and driveways. If staining persists, use a mold remover or bleach solution to treat the area. Then scrub the stain with a brush and rinse thoroughly with clean water.

For indoor concrete mold and mildew stains, avoid sweeping the area since that can spread mold spores. First, open windows to allow fresh air to circulate while cleaning. Spray the area with either a mold remover, mild detergent and water or a bleach solution if potential discoloration isn’t a concern. Then scrub the area with a brush and rinse the area with a clean wet mop. Check the area once completely dry to determine if the process needs to be repeated. 

Stubborn Concrete Stains

Muriatic acid and trisodium phosphate (TSP) can help treat deep, set-in concrete stains. However, muriatic acid should always be used carefully since it can cause severe burns and permanently damage your skin, eyes, and lungs. Be sure to read all the manufacturer’s instructions and wear heavy-duty protective clothing, including safety goggles, chemical-resistant gloves, long sleeves, pants and a respirator. Trisodium Phosphate (TSP) is another strong cleaner used to remove grease, mildew stains and paint from concrete. However, TSP has been banned in several states since it is highly acidic, so check local laws before purchasing. An environmentally friendly TSP alternative like a degreaser can also provide comparable cleaning.

Although concrete cleaning methods vary, with proper care and regular maintenance, you can remove and prevent stains, improving the longevity of your concrete.