When it comes to installing pavers for patios, driveways, walkways, or other outdoor spaces, utilizing the right base material is essential for ensuring the durability, stability, and performance of the paved surface. Two mostly well-known options for the base are open graded base (OGB) and dense graded base (DGB). While DBG was the industry standard for many years, open grade base has gained popularity in recent years as industry experts have realized its superior drainage properties and long-term performance benefits.
In this blog, we’ll take a closer look at the benefits of using an open grade base under pavers when compared to dense graded base, to help you make an informed decision for your next paving project.
Before diving into the benefits, it’s important to understand what these two types of base materials are:
These objectives align perfectly with the growing global awareness of climate change and the need for sustainable development. As a result, green construction has moved from a niche market to a mainstream approach in the building industry.
To truly understand green construction, it’s essential to look at its key components:
The most obvious advantage of using open graded base under pavers is its ability to facilitate water drainage. Open grade base, due to its larger particle size and the corresponding voids between the aggregates, allows water to flow through it easily. This reduces the risk of water buildup beneath the pavers, which can lead to shifting, cracking, or heaving over time.
In contrast, dense graded base has fine particles that can compact tightly and clog void spaces, leading to poor drainage. This leads to pooling water that saturates the base, leading to structural issues in the paved surface. Sinking and settling among the most common of issues seen in paver installations done over DGB.
Open graded base provides excellent strength and stability for pavers, making the pavement resistant to sinking, settling, and shifting when compared to its dense graded opponent that over time often experiences structural problems.
Frost heave is a common issue in colder climates, where water beneath paved surfaces freezes and expands, causing the surface to lift or crack. As water is able to drain freely through the open grade base, the likelihood of freeze-thaw cycles causing damage to the pavers is drastically reduced.
Dense graded base can trap water which might freeze, making it more susceptible to frost heave resulting in surface instability.
For environmentally conscious builders and homeowners, open grade base is much preferred due to its permeability. Water is able to pass through easily and promotes stormwater infiltration into the ground, which can help reduce runoff and prevent flooding, compared to DGB that contributes to increased runoff and exacerbates localized flooding during heavy rainstorms. This is particularly important in areas with stringent environmental regulations or where stormwater management is a concern. For us, in Texas, this is the case in heavily developed metropolitan municipalities (Houston, Dallas, San Antonio, etc.).
Installing a paved surface with open grade base can be quicker and easier than using dense graded base. The larger, more uniform particles in open grade base are easier to work with, as they don’t require as much compaction or grading. Hardscape or pavement installations are often delayed due to rain as the base material when using DGB has to completely dry out before work can continue. This causes unnecessarily lengthy delays to construction that are easily avoided by using OGB as OGB does not have to be dry for work to continue. Additionally, because the material has superior drainage properties, it is less likely to need ongoing maintenance to address issues related to water pooling or surface instability.
Preston from Hardscape Mentor coined the phrase “open graded gospel” and it is, in fact, so. While both open grade base and dense graded base can serve as foundation layers for pavers, open grade base offers several distinct advantages making it the ideal choice in any circumstance. From its outstanding drainage capabilities to its long-term stability, frost resistance, and environmental benefits, open grade base improves both performance and longevity of paved surfaces.
For those seeking a durable, sustainable, and low-maintenance solution for their outdoor paving projects, open graded base the only way to go. Whether you’re working on a small walkway or a large driveway, choosing the right base material will make all the difference in ensuring the success of your project.
Here’s the cliff notes:
Benefits of Open Graded Base
