Tips on How to Safely Remove Graffiti from a Historic District

Graffiti Removal Tip Sheet 

Removing graffiti can be complex in a historic district like Downtown Louisville Kentucky.  Here are some detailed guidelines on how to safely remove marks from your building.

Common Methods of Graffiti Removal and Concealment 

• Paint – Simple, cost effective and safest method to concealing graffiti
• Removal Products (Level 1) – Includes aerosol and cleaning wipe based removers  
• Removal Products (Level 2) – Industrial strength products requiring more care when using 
• Pressure Washing – often paired with a removal product for maximum effectiveness
• Restoration Professional – recommended for historic buildings or facades with sensitive surfaces

Painting Over Graffiti

This Method looks best on buildings or surfaces that are already painted, such as painted brick.  If you have a natural or unpainted surface you may prefer one of the removal methods.  Once you’ve determined painting over a tag is the best method for you, you can use the following parameters as a general guide.

Prep:  You’ll want to ensure the area to be painted is clean, free from debris/dust, and dry before painting.  For an extra detailed completed look, you can fill in any cracks or surface defects with an appropriate filler. Using tape, it’s best to “box out” the area to be covered leaving sufficient space between the edge of your outline and the graffiti tag itself.  

 

Priming:  Prime all areas of graffiti with one full coat an outdoor primer sealant in accordance with the manufacturer’s instructions. Allow a minimum drying time of two hours in normal drying conditions.

 

Painting:  For best results apply 2 coats of a color matched exterior paint in accordance with the manufacturer’s instructions allowing 1 hour drying periods between coats.  A roller, wide brush or paint gun can be used to apply the paint.  Most paint vendors and hardware stores can assist with color matching paint to your existing surface.   

 

Removing Graffiti Using a Chemical

This method physically removes the graffiti, instead of just concealing it, by using products with active chemicals which remove the graffiti from the surface.  While this method can be very effective you must carefully follow all manufacturers instructs and be very mindful of the surface you are using it on as they are often strong enough to damage sensitive and painted surfaces.   Additionally you should check with your state or local regulations to ensure a particular product is environmentally acceptable in your area. You should always test any removal product in a small, inconspicuous area before wide scale application to safeguard against unwanted surface damage of your application site.  Always use Personal Protective Equipment when using chemical removers following the manufacturer’s direction.

Level 1 Removal Products: most effective on smooth surfaces such as glass, metal, and some plastics and small to medium sized tags (e.g. Zep Graffiti Remover, Betco Graffiti Remover, Goof Off, etc.).

Level 2 Removal Products: best when used on unpainted brick, concrete, wood and other approved surfaces that are medium to large in scale according the manufacture of the specific product in use (e.g. Elephant Snot, World’s Best Graffiti Remover, Taginator, etc.).

Pressure washing

This method involves using hot or cold water pressure washing equipment to remove graffiti.  Especially when combined with chemical removers, this is an extremely effective technique but extreme care must be given as strong pressure can erode the surface of the area being cleaned and cause etching.  Additional tips:

• Hot water pressure washing will be more effective than cold water pressure washing. 
• Nozzles and tips should have a wide spray (nothing more aggressive than a green tip or 25 degree nozzle)  to avoid etching.
• Test your surface before largescale pressure washing to ensure durability.
• Using a graffiti removal chemical in conjunction with pressure washing will increase the effectiveness and speed up the removal process.

 

Removal on Sensitive Surfaces

In our downtowns there are often beautiful historic buildings and structures built with specialized materials.  Materials such as stucco, plaster, historic brick with limestone mortar, sandstone and similar must all be handled with the utmost care.  In these cases, we always recommend using a professional restoration company or other professional that specializes in graffiti removal.   Historic preservation and urban design departments within your city or other local agencies can be a valuable resource in choosing a professional service.  A qualified professional should always understand the risks involved and know the correct eradication method for your building.   

 

Needed Tools for Graffiti Removal:

• PPE – Gloves, eye protection, a mask or face shield is using certain chemicals 
• Paint Supplies – primer, color matched paint, rollers, brushes, tape and drop cloth
• Pressure washer – cold or hot water, wide angled tip
• Brush – stiff nylon brush to aid in removal and prepping the area
• Graffiti Remover – aerosol, removal wipes or industrial grade depending on your application

 

Additional Resources

 

Graffiti Removal Basics – https://www.wikihow.com/Clean-Graffiti

Preservation Removal Brief –  https://www.nps.gov/tps/how-to-preserve/briefs/38-remove-graffiti.htm

Printable Graffiti Removal Tip Sheet –  https://louisvilledowntown.org/wp-content/uploads/2020/06/Graffiti-Removal-Tip-Sheet.pdf