Permeable Pavers &Porous Paving

Permeable pavers allow stormwater to pass through the surface and into underlying aggregate layers where it infiltrates into the soil or is stored temporarily before slowly releasing. Water enters through joints between pavers (permeable interlocking), through the paver material itself (porous concrete/asphalt), or through openings in the paver (grass/gravel pavers). The aggregate base acts as a reservoir that filters pollutants and allows controlled infiltration.

Main types include: Permeable Interlocking Concrete Pavers (PICP) with enlarged joints filled with aggregate. Porous concrete and porous asphalt with open void structure. Grass pavers (grid systems that allow turf growth). Gravel pavers (grids that contain loose aggregate). Permeable clay brick pavers. Each type suits different aesthetic and functional requirements—from parking lots to residential driveways to fire lanes.

Yes, properly designed permeable paver systems can handle everything from passenger vehicles to heavy trucks and even fire apparatus. Load capacity depends on the paver thickness, pattern, and base design. Interlocking concrete pavers are available in thicknesses from 60mm (residential) to 120mm+ (heavy industrial). The aggregate base must be designed for expected loads in addition to storage requirements.

Permeable pavers require different maintenance than traditional paving. Vacuum sweeping 2-4 times annually removes surface debris that can clog joints. Avoid sand or salt application that clogs pores—use approved deicers. Promptly repair any damaged or settled pavers. Periodically test infiltration rates and remediate if needed. Prevent sediment-laden runoff from adjacent areas. Overall maintenance costs are comparable to traditional paving when properly planned.

Permeable pavers actually perform well in cold climates. Water drains below the frost line rather than sitting on the surface, reducing ice formation. The aggregate base provides stability during freeze-thaw cycles. Studies show permeable pavements have fewer freeze-thaw problems than conventional pavement. However, use proper cold-weather installation techniques and approved deicing materials to maintain long-term permeability.

New permeable paver systems typically achieve infiltration rates of 100-1,000+ inches per hour through the surface layer. Actual system performance depends on joint aggregate condition and underlying soil permeability. Even after years of service with proper maintenance, systems maintain rates far exceeding rainfall intensity—typically 10-20+ inches per hour. This far exceeds the 1-2 inch/hour rates of most design storms.

Yes, but the design must account for low infiltration rates. Options include: oversized aggregate base to provide adequate storage volume, underdrains that slowly release stored water to the storm system, overflow connections to handle excess volume. With these adaptations, permeable pavers provide water quality benefits and reduced peak runoff even when full infiltration isn't possible.

Initial costs are typically 10-30% higher than conventional paving for material and installation. However, permeable pavers often reduce or eliminate separate stormwater management requirements (detention ponds, pipes, inlets), which can offset the premium. Life cycle costs are often lower due to reduced drainage infrastructure maintenance. Many jurisdictions offer incentives, credits, or reduced stormwater fees for permeable paving.

Grass pavers are grid systems (typically HDPE or concrete) that provide structural support while allowing grass to grow through openings. They create reinforced turf that handles vehicle traffic without rutting or compaction. Common applications include overflow parking, fire lanes, emergency access roads, and erosion control on slopes. They provide the appearance of lawn with the functionality of a paved surface.

Permeable pavers are a recognized Best Management Practice (BMP) that helps meet stormwater regulations. They address multiple requirements: volume reduction through infiltration, peak flow reduction through storage, water quality improvement through filtration, and groundwater recharge. Many jurisdictions give permeable paving credit toward Low Impact Development (LID) requirements, stormwater utility fees, and green building certifications like LEED.