Do you have painted safety lines that you would like to remove? Perhaps the floor area is being repurposed and the safety lines are no longer useful in their current location. What should you do? This is a thorny problem. There are several things to consider before you begin removing safety lines or other paint from a concrete floor regardless of your chosen approach. The process of stripping paint from concrete floors is difficult—so much so that some contractors choose to leave the old lines in place—which creates confusion and can reduce the lifespan of newly painted lines. Consider the most common methods and associated challenges of removing paint from concrete, then find out why industrial floor tape is our preferred, low-maintenance alternative for marking safety lines.
How to Strip Floor Paint From Concrete
There are mechanical and chemical methods to strip paint from concrete floors. Chemical paint strippers break down the bond between the paint and concrete or other surface underneath so that the paint can be peeled away more easily. Grinding, soda blasting, sand-blasting, shot blasting, and other mechanical methods use friction to remove paint from the surface, but can also damage the floor beneath. Both chemical and mechanical paint removal methods are time-consuming and expensive, and will likely require surface repair work before new markings can be applied.
Is It Hard To Remove Paint From Concrete Floors?
Yes, stripping paint from concrete is challenging: Paint is often applied directly to uncoated concrete so it can be absorbed into the substrate, but this makes it harder to remove (see ASTM 4259, ASTM 4260, ICRI Guideline No. 310.2R). Chemical paint stripping is a messy process that involves sloshing around toxic, potentially harmful materials. For both mechanical and chemical methods, it may take several attempts before the paint is sufficiently removed.
What Is Left After Removing Paint From Concrete Floors?
Chemical paint strippers remove not only the paint but also other coatings. What will be left is bare concrete.
One of the biggest complaints about using paint to mark floors is what remains after it is removed: Most methods of stripping painted safety lines remove not only the paint itself but also any other coatings, leaving behind only bare concrete, or “ghost lines.” Chemical and mechanical paint removal methods strip everything—paint, other coatings, and tints included. This is especially true when blasting or grinding paint off concrete, as the abrasiveness is what takes paint off concrete surfaces.
Consider the following examples:
- On labels for chemical paint strippers, there are warnings that the product must not be used on colored concrete floors: This is because the product strips not only the paint but also the color from the concrete itself, leaving behind a ghost line.
- More aggressive mechanical methods, such as grinding and shot blasting, will not only remove all coatings but also roughen the concrete’s surface.
- Even if a gentler method is used, standard industry practice stipulates that concrete should be roughened before paint is applied to enable a stronger bond. As a result, stripping the paint with chemicals may still leave behind a roughened texture, while the rest of the floor remains smooth.
- When paint is removed from glossy, sealed concrete floors, the area where the safety line was will end up being dull in appearance while the rest of the floor remains shiny. You can of course re-seal along the safety line’s former path, but the new sealer may not exactly match the shade of the old, even if you use the same sealer that was originally put on the floor.
Test Your Floor Paint Removal Method
Before full-scale painted striping removal, test your chosen paint-removal method on a small, inconspicuous area of the existing safety line. Whether you choose a chemical or a mechanical approach, it’s unlikely that you’ll avoid damage to or indication of the previous paint on your floor. Testing in a small area will help you know what to expect—and give you time to come up with a plan for repair to reduce downtime.
Stripping the paint may leave behind a roughened texture
Industrial Tape Versus Painted Lines for Concrete
Professionals know that floor paint removal is time-consuming and can result in mismatches in color, texture, or shade where the safety tape used to be. Plus, redoing the whole floor is expensive and disruptive to operations. In contrast, industrial floor marking tape offers significant benefits over painting lines and striping on concrete floors and other surfaces:
- Minimal Preparation: The process of applying floor tape requires minimal preparation, especially when compared to paint: Simply clean and dry the floors, remove any lining from the tape, and tamp down the line to activate its pressure-sensitive adhesive.
- Durable, Long-Lasting: Unlike paint, which can chip or fade over time, our high-quality floor tape is engineered with beveled edges, a pressure-activated adhesive, and durable vinyl construction, so it stands up to heavy foot, forklift, or other vehicle traffic.
- Easy Removal: Our floor marking tape is easy to remove, and often comes up in one piece, without leaving any residue behind—no chemicals or aggressive mechanical methods required.
When comparing the benefits of floor paint versus industrial tape, the removal process may seem far a minor consideration, but it remains an important one. While chemical products may make stripping painted lines from concrete floors easier than mechanical methods such as sand-blasting, floor marking tape offers many benefits over traditional painting methods, making it the best option for concrete floors, warehouses, manufacturing facilities, and other industrial locations. For more tips and information about floor marking methods and safety in industrial spaces, explore our Resource Center.
References:
ASTM D4258, Standard Practice for Surface Cleaning Concrete for Coating (reapproved 2012), ASTM International, West Conshohocken, PA.
ASTM D4259, Standard Practice for Abrading Concrete (reapproved 2012), ASTM International, West Conshohocken, PA.
ASTM D4260, Standard Practice for Liquid and Gelled Acid Etching of Concrete (reapproved 2012), ASTM International, West Conshohocken, PA.
ASTM D6237, Standard Guide for Painting Inspectors (Concrete and Masonry Substrates) (2009), ASTM International, West Conshohocken, PA.
ICRI Guideline No. 310.2R, Selecting and Specifying Concrete Surface Preparation for Sealers, Coatings, Polymer Overlays, and Concrete Repair (2013), International Concrete Repair Institute, Rosemont, IL.
SSPC SP 13/NACE No. 6, Surface Preparation of Concrete (reaffirmed 2003), The Society for Protective Coatings, Pittsburgh, PA.
