Commercial parking lots, roadways and driveways must be able to withstand heavy loads, large volumes of traffic, and a variety of weather conditions with a minimal amount of maintenance and a long lifespan. Traditionally, the most durable and cost-effective materials for commercial paving applications have been asphalt and concrete, but now there are a wide variety of alternatives, including permeable pavers.
Unlike typical asphalt and concrete surfaces, permeable pavers provide a surface that is porous to rainwater and other liquids, eliminating the costly and complex drainage and retention systems that are often necessary for concrete or asphalt installations. They are also easy to install, lightweight, and can be filled with locally available materials, simplifying their installation.
Here is a detailed look at the advantages and disadvantages of each type of commercial paving solution.
The most common commercial paving material used in the United States is asphalt, because it is inexpensive compared to concrete, readily available, faster to install and easier to repair. The finished surface has a reasonable degree of flexibility, allowing it to be used in areas where concrete would crack due to changing soil conditions, frost upheaval or erosion. It is very cost-effective, especially for larger applications, and is similar in price to permeable pavers.
Asphalt, however, does have some serious disadvantages. The material is technically a form of concrete, made by combining an aggregate such as gravel, with asphalt, a petroleum product that acts as a binder. The asphalt can be found naturally or synthesized from other petroleum products.
As a petroleum product, asphalt contains significant amounts of hydrocarbons and other chemicals that both make it difficult to recycle and potentially harmful to the environment. Additionally, asphalt is a non-renewable resource with a limited supply, and the environmental impact of extracting, processing and using the material can be significant.
Compared to concrete, asphalt is softer and much less durable, requiring frequent maintenance to fill potholes and to seal cracks, especially in areas with high sun exposure where the heat softens the asphalt and accelerates its degradation. The darker color of asphalt also absorbs more heat than concrete, contributing to the “heat island” effect in urban areas that increases cooling costs and energy usage.
Asphalt surfaces also require an extensive drainage system to collect stormwater in order to prevent flooding problems during heavy rain, as well as erosion. It also requires expensive equipment to heat and install the material, as well as a large labor force who must work in dangerous conditions with extreme temperatures and a high risk of injury.
Concrete is an extremely durable and long-lasting commercial paving solution when installed at the proper thickness, with effective reinforcement and expansion systems to prevent cracking and other damage. It absorbs less heat than asphalt, it is typically made from natural materials like rock and sand, and it can easily be ground down at the end of its life cycle and used for other purposes, making it more environmentally-friendly than asphalt. It can also be stamped and colored easily to make a variety of attractive colors and patterns, such as realistic cobblestone patterns, and some formulations are even porous, like permeable pavers.
Unfortunately, concrete is also extremely expensive compared to asphalt or permeable pavers, and it is prone to cracking, as well as damage from frost upheaval or erosion. Concrete is time-consuming and labor-intensive to install, requiring heavy machinery such as concrete trucks or pump trucks, a large team of experienced workers, special finishing equipment, and purpose-built forms to shape the material. Most commercial concrete applications also require an extensive drainage system, increasing the overall price and complexity of the installation.
Like concrete and asphalt, permeable pavers are an extremely long-lasting and durable paving solution. Before they are filled with gravel, limestone or any of the many other compatible materials, they offer a strength of over 6800 PSI, allowing them to be driven on by heavy equipment during the installation process. Once filled, they offer compression strengths of over 8000 PSI, allowing them to handle even the heaviest commercial traffic, such as tractor trailers, forklifts or construction equipment, and standard automobile traffic at high volumes.
They require less maintenance than either concrete or asphalt, and are not vulnerable to cracking, sun exposure, frost, rain or erosion. Permeable pavers are far less labor-intensive to install, because they are lightweight and can cover a large area quickly. The grids can easily be moved into position by a single person, cut to fit, if necessary, then interlocked with adjoining grids. Afterward, heavy equipment can be used to dump and spread the fill material, then compress it into the permeable pavers. No special finishing equipment is required, and no sealants need to be applied.
Permeable pavers are also more environmentally-friendly and sustainable than either concrete or asphalt. They are made from recycled materials and they can be filled with locally available products such as gravel, limestone, crushed glass or soil and grass seed. Due to their minimal weight, they are less expensive and carbon-intensive to ship. And because less heavy equipment is used during the installation, fewer emissions are produced. Finally, because permeable pavers are porous, they allow rainwater to drain naturally through the surface, refilling local aquifers and preventing erosion.
Permeable pavers do have a few disadvantages, however. The same amount of preparation is required for the subsurface as with other materials, and some heavy equipment is necessary for the installation. Additionally, though permeable pavers are far less expensive than concrete, they may cost about the same or slightly more than an asphalt surface, depending on the project requirements. Finally, permeable pavers are a relatively new solution for commercial paving, possibly making it more difficult to find experienced contractors for the installation.
Thanks to their many benefits, including reduced maintenance requirements, high durability and greater sustainability, permeable pavers make a great alternative to either concrete or asphalt for many commercial paving applications, and they are extremely cost-effective.