Can You Paint Asphalt? What to Consider When Coating Parking Lots
Description: Asphalt is a very particular material to work with. When coating asphalt, there are specific types of paints, equipment, and methods you should be using.
In the paving industry, asphalt concrete is a material (commonly known as pavement or simply asphalt) made out of mineral aggregates and a sticky, black petroleum-like liquid. This material is most often used as the main tool for surfacing parking lots, sidewalks and roads.
There are many reasons why someone would want or need to paint asphalt, such as for painting the lines used to separate parking spaces in parking lots and structures. Another reason may be to give a more aesthetically pleasing or uniform appearance to the asphalt.
However, not all paints are suitable for this material. It’s essential to know the measures needed to paint asphalt, as well as the right type of paint you need to use to get the job done.
Can Asphalt Be Painted?
The material that constitutes asphalt is oil-based, therefore not all paints will be able to stick to asphalt surfaces. Some people will attempt to use the most common mainstream paint and traditional painting methods. However, many mainstream types of paint will cause asphalt to chip, crack, or peel.
Types of Paint Suitable for Asphalt Areas
- Water-Based Latex Paint
These paints are called “latex” due to originally having a rubber base. Nowadays, their base is water-soluble. Water is used as a carrier for the paint, along with pigment and a binder, which allows them to provide optimal long term color retention. Additionally, water-based latex paints dry very fast and have less odor.
Water-based paints can be an alternative for most oil-based paints, but not the other way around. Unlike oil-based paints, they do not use solvents (also known as thinner) and can be easily washed out with soap and water. Because of this, this type of paint needs to be used in cases where the asphalt has already been coated and sealed with another paint,, like coal tar.
- Acrylic Paint
When we talk about using acrylic paint for painting asphalt, it should be pure 100% acrylic paint, which makes it highly flexible and durable. This type of paint is also water-soluble but is also based in polymers, so the chemicals in the paint allow for higher elasticity. In the long term, this will prevent the paint from lifting off when placed on asphalt parking lots.
100% acrylic paint is also very fast to dry, but unlike water-based paint, it is not removed easily by water and is instead resistant to different types of weather and tear that could lift off the paint from the asphalt.
- Oil Based Paint
Oil-based paint, as its name indicates, uses pigment suspended in natural or synthetic oils, typically including linseed oil. It also includes solvent thinner resin, which evaporates as it dries, creating a hard coat of paint. As is necessary for asphalt paints, oil-based paint is very durable and will last a long time.
It is difficult to remove, which makes it resistant to wear and tear, but it also has a much stronger odor than other paints and will take a much longer time to dry. Although oil-based paint is long-lasting, it is not flexible, so it might eventually result in cracking.
- Coal Tar Paint
Coal tar paint is not recommended to be used alone, but rather as a sealant in combination with acrylic or latex paint. Using coal tar for sealcoating allows for a protective layer from weather and sunlight damage. This type of paint is less expensive than the others, but it also has more dangerous qualities.
Coal tar sealant is made out of toxic chemicals called polycyclic aromatic hydrocarbons (PAHs). When not handled correctly, these chemicals can be harmful for the environment and poisonous for both animals and humans. This is why it’s necessary to use proper equipment and techniques when working with coal tar paint.
Things to Consider When Painting Asphalt
Painting asphalt is a unique process with specific steps to take for a safe and optimal result. Firstly, the asphalt surface needs to be thoroughly cleaned before any paint is laid. Use soap and a water-based cleaning agent to scrub away any oil, dirt and grease on the asphalt. If possible, you can also use a pressure washer. If there are any stains left behind, it can result in uneven coatings of paint that are not properly sealed into the material.
The next step for preparing your parking lot (or any other asphalt surface) for painting is to seal coat it. Many professionals use a roller to apply two coats of clear or tinted asphalt sealer to the surface. This will serve to help fill small dents and cracks to provide an even surface to paint over. This can take up to 24 hours so the sealant can dry and heal itself.
It’s necessary to take safety measures and use protective equipment when doing this process. This includes wearing appropriate clothing to protect your skin from toxic chemicals and using drains and barriers to block the product from reaching and damaging any area outside of the asphalt surface.
After you’re done prepping, you can begin to paint the asphalt. This can be done using paint rollers and/or spray tools. You should not be using paintbrushes since they will take much longer and provide uneven coats. For parking lot lines, you can use a line striper to facilitate the process. It’s a good practice to apply at least two coats of paint, including a protective clear layer.