Pavers themselves can technically allow some water to pass through their material, but true permeability is not inherent to the paver unit alone. Instead, it depends significantly on the entire paver system's design and installation.
According to information provided, while any paver can allow water to pass, true permeability depends on factors like base material, joint width, void percentage, and joint fill type. These elements must work together to maximize water infiltration, which is crucial for effective stormwater management and reducing strain on municipal systems.
Understanding Permeable Pavement Systems
A pavement system designed for permeability goes beyond just the paver unit. It's a holistic approach where each layer facilitates water flow down into the ground rather than letting it run off the surface.
Here are the critical factors that determine if a paver installation is truly permeable:
- Base Material: Unlike traditional pavements that use compacted, impervious materials, permeable systems utilize layers of open-graded aggregate (like crushed stone) that have large voids for water to flow through and be stored temporarily.
- Joint Width: The gaps between individual paver units are wider than in conventional installations. These wider joints are the primary pathway for water to enter the system.
- Void Percentage: This refers to the amount of empty space within the aggregate base layers and the joint fill material. A higher void percentage means more space for water storage and infiltration.
- Joint Fill Type: The material filling the wider joints is not sand or mortar (which are relatively impermeable) but typically angular crushed stone or specific permeable aggregates designed to allow water to pass freely.
When these components are correctly implemented, the permeable paver system allows rainwater and snowmelt to infiltrate the subsoil, recharging groundwater and minimizing surface runoff. This is a key difference from traditional impermeable paving, where water is directed to drains, often leading to overwhelmed stormwater systems and potential flooding.
Therefore, while a paver is the visible surface layer, its permeability depends entirely on whether it is installed as part of a specifically designed permeable paving system incorporating the right base, joint fill, and joint dimensions.
