Having been in the landscaping and interlocking brick installation business for over 40 years, I've witnessed the evolution of materials and techniques used for parking pads and driveways. Over time, we've seen what works and what doesn’t when it comes to creating durable, long-lasting surfaces that also support environmental sustainability through permeability.

Through years of trial and error, we have embraced the recommended bases for semi-permeable pavers. These bases have significantly outperformed traditional methods, leading us to switch to this system for all of our paver installations including patios and walkways.

When I first started in this industry, the common base installation involved using a sub-base of Granular A and screeding with concrete sand. Although compacting this material to 98% Proctor density was the recommendation, it rarely worked as intended. The problem? Most landscapers didn’t have access to the heavy tamping equipment required to achieve that level of compaction. Even those who did often underestimated the amount of time and effort needed to reach a 98% compaction rate. Over time, this resulted in tire rutting and structural degradation—issues that became apparent only a few years after installation.

For the past six years, we've adopted a more reliable, industry-backed system. This involves excavating 12 inches and installing a DriveGrid layer followed by 8 inches of 3/4" clear gravel, also known as ASTM No. 57. This crushed, angular, open-graded base material has an exceptional infiltration rate of over 500 inches (12,700 mm) per hour.

On top of this base, we lay a screeding layer of High-Performance Bedding Gravel (HPB), also referred to as 1/4" chip stone. Like the clear gravel beneath it, HPB is crushed, angular, and has a high void space that allows for rapid water infiltration, again exceeding 500 inches per hour. This structure not only promotes permeability but ensures long-term stability, even under heavy use.

At the heart of this system is DriveGrid Geogrid, an innovative material specifically designed to stabilize the base of trafficked surfaces. Its multi-directional triangular geometry improves in-plan stiffness, reducing the amount of gravel required to achieve the same load-bearing capacity. DriveGrid Geogrid's advanced design eliminates the need for a thicker sub-base without compromising on performance.

When we encounter areas with soil that drains very slowly, we take extra measures by installing a drainage pipe, directing the water to a soak-away pit under an adjacent garden or lawn. This ensures that any excess water can drain away efficiently, preventing pooling and maintaining the integrity of the parking pad. Since adopting this method, we’ve entirely eliminated tire rutting in our parking pads, providing our clients with a superior, more resilient surface.

Switching to a permeable paver base not only offers a sustainable solution but also ensures durability. These installations can handle the stresses of daily use without sacrificing aesthetic appeal or structural integrity. With Toronto’s weather extremes, having a well-designed, permeable base is essential for long-lasting driveways and parking pads, and even patios and walkways.