Concrete Cleaning – How to Remove Tough Stains Easily

After months and years of heavy traffic and tread, many concrete surfaces accumulate dirt over a period of time.  Oftentimes it’s difficult to notice the change in the concrete appearance, but once a concrete surface is cleaned, it’s amazing how much better the surface looks. Many homeowners opt to schedule periodic cleaning to avoid the gradual accumulation of dirt on concrete, and the most effective way to clean concrete without damaging its surface is power-washing.

Before making the decision to clean your concrete with a power-washer there are some things you should know:

Concrete Cleaning equipment: What you will need

Power washers are the most effective way to clean concrete. Most power-washing equipments are easy to use and the cleaning procedures are hassle-free. For effective cleaning, you should consider using a power washer with a pressure rating of approximately 3000 psi, and a flow rate of about 4 gallons per minute.  Although higher pressures may be required to remove tough stains such as paint and heavy tire-skid marks, however, 3000 psi does the trick for almost all concrete cleaning jobs. 

Water temperature: Hot or Cold Water

Power washers that use cold water are cheaper, lighter, and simpler to use than hot-water units. On the other hand, hot water cleans faster than cold water, even when using power-washing equipment. Cold-water units are suitable for removing dirt and are sufficient for smaller, residential applications. Most commercial power-washing is done with hot water, as it is especially effective in cleaning tough oil and grease stains.

Chemical cleaners: What to Use for What Type of Stain

Usually water alone is able to remove dirt from concrete, cleaning chemicals are often required to remove more stubborn as well as specific stains. Spraying the stain with the chemical cleaner and letting it sit for about 15 minutes before power-washing is often recommended.

Oil, grease, etc – Removal of oil and grease from parking lots, drive-through and other concrete pavements is the most common concrete power-washing application. Apart from hot water, an alkaline degreaser greatly helps in removing oil and grease stains. Hot water lifts the oil from the concrete, while the degreaser allows the oil or grease stain to be flushed from the surface.

Rust – Rust stains can penetrate deeply into concrete and can prove to be tough to remove completely, however, chemical cleaners with oxalic acid are most effective for these stains. 

Graffiti – Graffiti can be difficult to remove depending on the type of paint used. Citrus-based solvents are the least aggressive but the safest to use. Cleaners containing potassium hydroxide when soaked into the concrete surface for several hours before power-washing also prove to be quite effective.

By understanding the right equipment, water temperature, and cleaning chemicals your concrete cleaning job will require, almost all dirt and stains from concrete can be cleaned without a lot of effort and elbow grease!