Words: Vanessa Salvia
Some might argue that graffiti is an art. There’s also an art to removing graffiti and protecting a wall or other surface from graffiti in the first place. If you approach graffiti removal incorrectly, it’s not going to work. On the other hand, removing graffiti too aggressively can damage the substrate. We spoke with experts at Diedrich Technologies and Prosoco to get the top things they wish contractors knew about graffiti removal (and why it doesn’t have to be so hard).
Jake Boyer is head of Prosoco’s Clean and Protect Group of Masonry Cleaners and Protective treatments. He says the No. 1 mistake he encounters on graffiti removal jobs is that people attempt to remove graffiti with high pressure, and that doesn’t work. He says putting a zero-degree tip on a sprayer and then placing the sprayer an inch from the surface does blast the graffiti off, but it also removes the surface itself. “There are only two ways to remove anything on a fundamental level — dissolve the stain/soiling, or attack the interface between the stain and substrate by breaking down microscopic particles of the substrate,” he says. “We want to solubilize the stain while leaving the substrate intact and not just go at it with higher pressure, which will erase the face of the masonry.”
Linda Potter, CSI, CDT, is the Manager of Architectural Services at Hohmann & Barnard and Diedrich Technologies. She says to take note of anything adjacent to the graffiti that may be affected by the cleaner and cover and protect it. “Pre-wet any landscaping and other surfaces not intended to be cleaned,” Potter says.
Another thing to keep in mind is that graffiti is not all the same. The graffiti “artist” could have used spray paint, sharpie, lipstick, or white-out, and each substance will react with the substrate differently and require a different removal strategy. “Each of those could require a different chemical composition to remove it effectively without damaging the substrate,” Boyer says, “and a product that could be harmless to one substrate could irreparably damage another.”
So how do you know what removal approach to take? Boyer says that involves some trial and error. Although you may never truly know exactly what you’re dealing with, you can use your best judgment to make some informed guesses. For instance, if you found a can of spray paint in an alley near some fresh graffiti, it would be reasonable to assume you’re dealing with spray paint. However, there are numerous different chemistries even within spray paint.
If you can narrow down the substance or family of substances you can avoid some trial and error, but even if you are pretty sure of what you are dealing with it’s always recommended to do a test panel on a small sample of the substrate. “Always try the first product and be prepared to try your second,” Boyer says. “With some chemistries, you’ll know if it’s going to work or not in just a couple minutes, but others may need an extended dwell time to have a chance to work. Just because it didn’t do anything in the first 10 or 20 minutes, doesn’t mean that it won’t make a big impact after 30 minutes or more, even hours sometimes.”
The quicker you remove the graffiti, the easier it will be to get off. “If you can clean within 24 hours you have the best opportunity to remove it without damaging the masonry,” Potter says. The longer the graffiti has been on the building, the higher your chances of permanent staining are.”
Along with both patience and acting fast, temperatures and conditions are important to consider. Colder temperatures have a dramatic impact on the performance of most products, Boyer says. If you have access to hot water, that can make removal easier, or if not, performing the removal on a warm, sunny day may work better. “With ambient temperatures being largely out of your control, plan accordingly and expect a longer dwell time in colder temps,” Boyer says.
Preventing graffiti is usually a better way to spend your time. Graffiti experts recommend prepping the surface to avoid graffiti from bonding with it in the first place. An anti-graffiti product should be breathable and penetrating, and provide both water resistance and graffiti resistance in one product. He says taking the simple step of protecting your surface can avoid a situation becoming a problem and lowers the cost of your wall does get tagged.
“It’s hard for people to think about what you might need to address for the future when it’s not right underneath your nose,” he says. “A simple application of a product like Blok-Guard & Graffiti Control would be the best preventative measure you could take. It provides more than just graffiti resistance, but also water resistance to keep the wall clean from other common stains as well as graffiti.”
Even when a surface is protected, graffiti can still happen, of course. But hopefully, the protective coating prevents the graffiti from penetrating as much as it would have otherwise and makes it easier to remove. The use of anti-graffiti coatings is highly recommended if your building is in an area that is more prone to vandalism or graffiti, Potter says. “Anti-graffiti coatings don’t change the appearance of the masonry, but offer a layer of protection so the graffiti doesn’t get absorbed into the masonry unit as quickly, giving you an opportunity to remove it before it absorbs into the masonry unit itself,” she says.
Hiring a graffiti removal team does have some costs, but it can save you the time of having to do it yourself. Potter says that removers are available through distribution across every major city in the U.S. and do not require a special license or certificate in order to apply. “This does keep the cost manageable for the building owner,” she says.
If you are in a position of having to clean graffiti from an unprotected surface, clean it, and then choose a product to protect your surface going forward. There are two main types of anti-graffiti coatings — sacrificial coatings which form clear-coat barriers over the surface being protected, and permanent non-sacrificial coatings. A sacrificial coating is so-called because if the surface is vandalized, the protective coating can be removed (sacrificed) and takes the graffiti with it. Boyer says using non-sacrificial treatments can cut the removal time to a fraction of what it would be on an untreated surface.
Finally, Boyer says to seek out support. “Work with a product manufacturer that has local field support who will come out and do a test panel for you so you’re not beating your head against the wall,” he says.
Potter concurs: “Using a company who has experience in removing graffiti is worth the investment,” she says. “I’ve seen attempts at removing graffiti end up worse than the graffiti originally was.”