How do I Remove Paint from Asphalt & Concrete?Posted on October 23, 2013 by Rafael Cantillo
The Property Manager's Guide to Paint Removal on Asphalt & Concrete
First and foremost, it is important to always consult with a knowledgeable parking lot maintenance contractor on the exact nature of your paint removal project. With the countless variables that can arise on any given project, there is no "one size fits all" approach. With that in mind, this article is written to let people know what most of their options are with regards to paint removal as well what option is the best fit by our own experiences. By no means should anyone take this article as a "how to" guide, because it was not written for that purpose. We hope you enjoy the article and please feel free to contact us with any questions you may have.
As the founder and moderator of the "Parking Lot Maintenance Information Request" group on the website LinkedIn, we see a lot of interesting questions that come up there from time to time. So we decided to post some of them here.
- Paint Type:
- Surface Damage:
- Environmental Impact:
Paint Out / Grey Out / Black Out:
Covering paint with paint. Typically by using a paint which is the color of the surrounding surface such as black for asphalt or grey for concrete.
Pressure Washing w/ Chemical: Using a low pressure washer (typically up to 3300 psi and can be heated or cooled with a chemical paint stripper) to remove paint from concrete with little to no surface damage. All water must be reclaimed when using this process.
Sand Blasting / Dry Ice Blasting: A process in which sand, glass beads, or another medium is shot at high speeds through a machine across the surface of a hard material until it is smooth. Sandblasting is often done to remove a previous finish on an item, to remove rust, or to prepare a surface to receive a new coat of paint. The kind of medium used to blast the surface depends on how difficult the removal is and how much impact the material can withstand. To learn more about sand blasting media here is a great page of information.
Dustless Blasting: The Dustless Blaster works by mixing water and abrasive inside the blast tank. By introducing water it drastically increases the mass and energy the machine is putting out, while eliminating dust. Imagine throwing a handful of dry sand, versus throwing a handful of wet sand; which one is going to have a more significant impact on the target? Not only will the wet sand hit the target harder, but it won’t disintegrate and become a cloud of dust like the dry sand will.
Shot Blasting: Shot blasting is the process of mechanically blasting concrete with tiny steel shots at a very high velocity. This process typically removes up to 3 ml of the concrete's surface to reveal a rough profile for improved bonding. The concrete dust is recovered by a powerful dust collection system leaving little to no mess or contaminants on the project.
Asphalt Grinding: An asphalt grinder is a walk-behind machine that removes almost all paint types found on asphalt. The machine is typically used for removing lines from roads and highways. It removes all of the paint as well as up to a 1/4 inch depth of the asphalt’s surface. Ground surfaces usually blend in overtime.
Water Hydro blasting: Hydro blasting, also referred to as water blasting is a newer technique for cleaning and profiling paved surfaces. This process includes equipment that pressurizes water at a extremely high psi (starting around 10,000) to clean and profile concrete or asphalt surfaces. The equipment can be enclosed to reclaim the water, as well as remove contaminants and clean the surface profile. The pressure can be adjusted depending on how much profile you are looking to remove.
There can be many different scenarios where paint removal from asphalt or concrete is needed. Below are a few scenarios to consider, but it is best to leave the ultimate solutions to the professionals. Let us know if you have one we haven't mentioned here.
How do I Remove Paint from an Asphalt Parking Lot?
Whether paint on asphalt needs to be removed because of a layout error, stencils not matching from one contractor to the next, or even just a plain old paint spill or over spray, you have several removal choices at your disposal.
Most contractors are going initially offer the option to black out the conflicting paint first. Although this isn't technically removing the paint at all, it is certainly the least expensive and fastest way to deal with the problem. Also, considering that most parking lots are typically on a seal coating schedule every few years, the paint will be covered with the new seal coat as well.
Often times people think that sand or dustless blasting will be a good fit, but when you add up the cost of a rental or contractor, the mess blasting can make, the noise the equipment puts out, and the need to barricade or shut down large areas surrounding the work area, It may not be such a great fit. Even "dustless blasting" can leave a film or layer of dust on vehicles, prompting phone calls for car washes or worse. Don’t get me wrong, these options can be a solid choice in the right scenario, it's just important to know what those factors are.
Another thought is that pressure washing with chemicals is a good choice, and if the paint is fresh and the environmental surroundings are good, it can be. However, if you're working around the general public, an area where animals are around, or a riverbed or harbor, then I would avoid it like the plague. It only takes one small splash of a caustic paint stripper such as Jasco paint remover getting into someone's eyes to put you in court smack dab in the middle of a lawsuit. A dog could lap up some pooled up water with chemical in it, or water could spill into a harbor or body of water, and the environmental fines start in the $10,000 dollar range.
When cleaning up a parking lot paint spill, our advice is to always black out conflicting paint using a waterborne traffic paint, and then install a fresh coat of seal over the area for an even cover. If that isn't an acceptable option, then go with the dustless blasting option, assuming it can be done during off hours. Sound ordinances can sometimes be an issue depending on the housing areas around you.
How Do I Remove paint on an Asphalt Street or Road?
This one is pretty straight forward. The factors that need to be considered include type of paint or markings that need to be removed, the ability to close off the street /road you're working on, and how fast you want to get the project done.
Viable removal options include water blasting, sandblasting, and grinding. The first question you need to answer is how big the project is. This will help you quickly dictate what option is the smartest one to choose. In my experience nothing is faster than water blasting. As your project comes down in size so should your approach. Small projects can be cost effectively done with sandblasting or dustless blasting, and if surface profiling is not a huge concern then asphalt grinding is very affordable.
How do I Remove Paint on a Concrete Warehouse Floor?
When it comes to removing paint on a concrete warehouse surface you have a lot of options. Again, the size of project is typically what will dictate which removal option is best. The first thing to do when looking at paint removal in a warehouse is to give it the scraper test. A good scraper can do wonders, but if it doesn’t, then on smaller projects consider using a chemical paint stripper. Whether you're removing latex or epoxies, chemical paint strippers can be very effective at removing paint.
If you're looking at removing anything over 100 linear feet of painted line, or a large paint spill etc, then the wise choice is definitely shot blasting.
Shot blasting has come a long way over the last few years with smaller machines and smaller blast patterns. It used to be that a 12" blast pattern was the only size choice available, but with the advent of reducers you can customize the pattern to practically anything. So if you are removing a 4" line go small, and If you're removing a 200' spill area go large.
One note of caution about shot blasting. This process does in fact remove the top layer of concrete from your floor. This is the smooth shiny layer of the concrete, and once blasted it will attract dirt and rubber build up if not treated with a strong epoxy sealer. Another choice is to polish that area and seal it, but it will look different than the original surface.
If you own your property and are not too concerned about scaring then you can blast away. As long as the freshly blasted areas are sealed with a clear epoxy, the scarring isn't that noticeable. If you do not own the property, then you may want to run it by the building owner or check your lease agreement. To remove patterns etched into concrete you have to blast the entire surface and then reseal it, and that can get pricey.
How do I Remove Paint in a Concrete Parking Structure?
The two main choices here are chemical pressure washing with and shot blasting. The pressure washing choice is very effective but a lot more time consuming. Like mentioned above water reclamation is mandatory, and I wouldn’t recommend it if you are located near a harbor or body of water. Shot blasting is fast and clean, but again you are profiling the concrete more than you would with pressure washing. If you are removing an area of parking lot stalls, it is best to remove the entire area, reconfigure the striping and seal the entire area.
How do I Remove Paint on Decorative Concrete?
Many shopping centers and businesses have decorative concrete driveways, and from time to time things like paint can get spilled or dripped onto them. Other scenarios might include seal coat tracking, oil leaks, and other similar issues.
The key to removing these spills correctly lies in testing to see what works, and what meets the customers expectation. It's important to note that no repair done to decorative concrete will leave it perfect, no matter what process is used. All repairs will cause some form of etching and/or leave a clean spot once completed. The best thing to do is an initial repair and then give it time to blend again over a few months. If you are still not happy with the results, then re-approach the issue with another repair.
These types of removal projects are typically handled on a case-by-case basis. Most repairs can be done using (low) pressure washing with a mild chemical stripper, or dustless blasting, or a combination of the two.
Lastly, Soda blasting can also be used for these types of removals, but the results are often no better than dustless blasting or pressure washing. If the product being removed has been down for long it may require something stronger to remove the damage.
How do I Remove Paint on Brick, Stone, and Soft Woods?
Just like above, "delicate" is the keyword. No matter what kind of blasting is done, there will be noticeable damage in the form of some sort of etching or fading.
How do I Remove Paint from Streets, Roads, or Freeways? (Concrete or Asphalt)
This is a simple one because hydro blasting / water blasting is a beast. On roads and airports it can't be beat. Removing traffic lines is an easy and safe process with Hydro blasting. Not only are removal rates incredibly fast but the process is environmentally friendly. Hydro blasting replaces old methods such as, asphalt planers, shot blasters, grinders, and sandblasting. The system leaves paved surfaces close to dry when treated which means they are ready for paint again. The instant vacuum recovery system built into them means that the eradication surface is damp only about 12 inches wide while all surrounding pavement remains dry.
With such close cleaning tolerances, any new marking areas are unlikely to be affected by the blasting of old markings. Water blasting reaches deep into the pores to extract paint without altering the surface height. A rut-free surface is a huge safety benefit. Safety is also dramatically enhanced by the absence of ambiguous “paint” since the pores are cleaned as well as the surface. Furthermore, blasting does not scar the aggregate, whereas grinding can leave a permanent scar. Water blasting can easily remove thermoplastic, waterborne paints, epoxy paints, and rubberized paints.
Lastly, the equipment scales just like how your projects do; so many different machine sizes for your many different project sizes.
How do I Remove Paint from Airport Runway?
Hydro blasting is the king here again for the same reasons mentioned above.
How do I Remove Paint from Concrete Curbs?
I am going to gear this section towards curb paint removal, even though we occasionally get a request to remove graffiti from curbs. If graffiti is your problem the quick answer is to paint over the graffiti with the color of paint that was there before. If the curbs were not painted, then we would use a chemical paint stripper and a wire brush. Always be sure to use protective gloves and eye wear when working with these chemicals, and be sure to barricade off the area keeping pedestrians far away.
Paint failure is the number one reason we get requests to remove paint from curbs. There can be many reasons for paint failure, and depending on how bad the failure is I would suggest different methods.
The biggest reason paint fails on concrete curbs is because a water based paint was installed over an oil based or epoxy paint. This is a classic mistake usually made by an inexperienced painter and it’s a shame because it starts a cycle of failure that is costly to repair. Other reasons for paint failure include poor surface preparation and moisture issues, but these usually can be fixed with scraping and or sanding, then simply repainting the curbs.
Depending on how much built-up paint is present, I would recommend different options. For a light coat of failing paint, or a fresh coat of failing paint I would recommend simple pressure washing. Latex paints such as standard traffic paints don’t have a lot of bond early on and pressure washing with chemicals should work. Do a small test first and be sure to use water reclamation. If the paint is heavy and stiff with many coats then it's time to consider scarifying the curbs. Don’t use circular grinders on curbs because they will leave round swirl patterns and the finish will be ruined. Instead, use a hand held scarifier.
The reason for this is because the cutters or teeth on the scarifiers will not profile deeply. They just grab the paint from the surface of the curbs. Leaving a nice and smooth surface ready for paint again. For a perfect finish after scarifying the curbs, follow it up with some dustless blasting to smooth out the finish. Your curbs will look brand new again. Dustless blasting alone typically cannot remove the thicker epoxy paints but it's great at getting the last smaller, lighter bits of paint that scarifying misses. If you plan to re-coat your curbs again then this part of the process can be skipped.
|Removal Options:||Cost:||Speed||Surface Impact|
|Paint Out / Grey Out / Black Out||$||Fast||Low|
|Pressure Washing w/ Chemical (ex vid)||$$||Slow||Low|
|Sand Blasting / Dry Ice Blasting (ex vid)||$$||Slow||Low - Med|
|Dustless Blasting (ex vid)||$$||Slow||Low - Med|
|Shot Blasting (ex vid)||$$||Fast||Low - Med|
|Asphalt Grinding (ex vid )||$$||Slow||High|
|Water Hydro Blasting (ex vid)||$$$||Very Fast||Med - High|
At Empire Parking Lot Services we utilize each and every form of removal listed on this page, and this advice comes from the years of experience working with all of them. It's important to know what option is the best fit before starting your project. Consult with a contractor and always focus on safety first.
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The information in this weblog is provided “AS IS” with no warranties, and confers, and no rights. This blog does not represent the thoughts, intentions, plans, or strategies of my employer. It is solely my opinion. Feel free to challenge me, disagree with me, or tell me I’m completely nuts in the comments section of each blog entry, but I reserve the right to delete any comment for any reason whatsoever (abusive, profane, rude, or anonymous comments) – so keep it polite, please.
Empire Parking Lot Services is a Southern California parking lot maintenance contractor with over 30 years of experience in parking lot, parking structure, and warehouse improvements. We specialize in helping decision makers improve the image of their properties through careful planning and management. Our approach has proven to save our customers time and money, while greatly improving their parking lots image.
Contact us today if you have any questions in regards to this article or your parking lot project.