How to Remove Graffiti From Concrete

Mechanical Cleaning Methods

The mechanical cleaning methods for concrete substrates include pressure washing, sandblasting, the dry and wet ice blasting. To use these techniques, you will need the proper equipment.

These methods provide higher safety than the chemical methods and are more environmentally friendly. Mechanical cleaning methods do not address the actual chemical nature of the bonds between the substrate (wall) and the spray/ paints applied on it; they merely use an abrasive force to separate the paint from the surface, in a similar way that we use to brush our teeth without toothpaste.

Pressure washing

This method uses pressurized water through suitable equipment.

Best for: most surfaces

Pros: 

• easy method

Keep in mind:

• A pressure of 2000-3500 PSI is needed for concrete surfaces
• Needs caution so that not a lot of water gets wasted down the drain
• Might not be very effective on tough-to-remove paints
• Not all municipal water exhibits the same hardness profiles, and keeping your device up and running for long durations will require using average hardness water

We recommend: Sun Joe Electric Pressure Washer

Sandblasting

Sandblasting makes use of an air compressor to shoot sand at a high velocity toward an object. It has various applications, and the removal of paint is one of the most common. The sand microparticles are shot to the surface, where they break the paint – wall bond and remove the paint coating.

Best for: brick, concrete, and metal surfaces

Pros: 

• quick method

Keep in mind:

• generates a lot of dust
• needs the right equipment and clothing to protect your body from the power of the sandblaster: wear at all times face mask and eye protection

We recommend: LE LEMATEC Portable Sand Blaster Gun Kit

Dry Ice Blasting

The dry ice blasting process uses a combination of compressed air and CO₂. Pelletized dry ice sublimates into a gas, which then dissipates into the atmosphere, and this instant freezing causes the paint to become brittle. Additionally, there is no further damage to the surrounding structures during the cleaning process.

Best for: oils, glues, food residues, or paint at various surfaces

Pros:

• Nonabrasive, non-conductive, non-flammable, non-toxic

Keep in mind:

• cost of CO₂ media
• only in well-ventilated spaces
• CO₂ footprint, environmental effects

We recommend: CRYONOMIC

Wet Ice Blasting

At the wet ice blasting process, frozen water particles are blasted out on a surface using compressed air.

Best for:

Pros: 

• Wet ice blasting uses micro-sized ice cubes which reduces the cost in comparison with dry ice blasting
• dustless, very environmentally friendly.

We recommend: Ice Storm 90

Chemical Cleaning Methods

Spray paints used for graffiti street art can be very strong and cannot easily be removed without the use of appropriate chemicals. They form chemical covalent bonds with the substrate that are very difficult to break. The market offers a variety of solvent solutions, but it is vital to choose the right one and use it safely. The most common principle of operation is extraction, whereas some chemicals could employ other more reactive approaches.

All chemical removers require dwell time. Longer dwell times allow for more effective removal of graffiti. Moreover, it is recommended that the graffiti removal process take place when the ambient temperature is high, especially in summer, since the graffiti can be removed more quickly.

If this is not an option, then the use of warm water can also increase the effectiveness of the methods. Finally, pressure washer equipment, which was mentioned in the previous paragraph, can be very effective when combined with a chemical cleaning method to rinse it, for achieving excellent results.

Bare Surface Graffiti Remover

It is a water washable graffiti remover for unprotected substrates in the form of thick gel.

Best for: bare, unprotected surfaces like walls of brick, stone, concrete or render surfaces

Pros:

• suitable to remove both aerosol and marker pen graffiti
• safe to use on porous and vertical surfaces

Keep in mind:

• not to be applied to sensitive material such as plastic, or previously painted surfaces
• use with caution and rinse it with copious amounts of water

Professional Graffiti Remover Gel

Blackfriar Professional is a graffiti removal gel that works on all kinds of different graffiti paintings.

Best for: wood, brick, natural stone, and concrete

Pros:

• gel form for enhanced adhesion to surfaces.
• easy to use product

Keep in mind: 

• use with caution and read all instructions carefully

We recommend: Prosoco Defacer Eraser Graffiti Remover

Green Paint Stripper

Chemical solution formulated as a foam that can be used to remove all types of oil and alkyd-based paints.

Best for: metal, wood, concrete, and mineral substrates 

Pros:

• environmentally friendly
• quick and safe method

Keep in mind: 

• use with caution and carefully read all instructions 

We recommend: Prosoco Paint Stripper