Permeable Pavers Installation – Step-by-Step Guide

•  For natural stone, material certification is more variable. It requires describing the type of stone, source region, compressive strength, and freeze-thaw test results. Granite, quartzite, and certain basalts are appropriate for vehicular-load permeable applications. Example of ASTM C666 freeze-thaw durability test results used to verify natural stone performance: 
  

• Softer sedimentary stones, certain sandstones, and some limestones require careful structural verification before being specified under the vehicle bearing conditions.

Both material types work within the same base and drainage systems. They are governed by ICPI Tech Spec 18,  ASCE 68-18, and EPA stormwater BMP guidance. Aggregate specifications ASTM No. 8 bedding, No. 57 base, and No. 2 subbase are applied regardless of the surface selected.

Step 3: Excavation and subgrade preparation

Step 3 of Permeable Pavers Installation is the proper excavation.

• Dig the full project area to a depth of 12 to 18 inches below the targeted finished surface. The base material area should extend a minimum of 6 to 8 inches beyond the perimeter of the paved surface to ensure edge stability.
  

• Remove all topsoil and any other organic material from the subgrade. If the soil is granular, compact it with a vibrating plate. Soil rich in clay subgrade may require a soil replacement with lime and crushed stone blend before compaction or any aggregate is placed.

The subgrade surface elevation should be verified and logged properly before base installation begins. Surface units cannot correct a poorly graded subgrade.

Step 4: Geotextile fabric

Step 4 of permeable pavers installation is installing the geotextile fabric. The fabric will be a separation barrier, lets water pass through, but prevents any fine particles from passing through. Without it, even a correctly specified aggregate system loses its drainage capacity as fines fill the voids over time.

• Directly lay the geotextile fabric on the compacted subgrade before any aggregate placement. Vertically apply the geotextile against the soil with a minimum 1-foot horizontal extension under the subbase on the soil subgrade.
  
  
• Where drainage is poor, and the solid is weak (CBR below 5%), increase the overlap to 2 feet. 
  
  
• Your selected geotextile specification should follow AASHTO M-288 for the specific application class.
  
  

Step 5: Subbase and Base Layers

Step 5 of Permeable Pavers Installation includes placing stone in lifts. Then compacting each layer for better stability while maintaining void space.

• Install the subbase using ASTM No. 2 stone in minimum 6-inch lifts. Each lift should be compacted with a 10-ton vibratory steel roller, making two vibratory passes followed by two static passes.
  
  
• Completion will be achieved when no visible movement occurs under the roller. Field density should align with at least 95% of laboratory index density in accordance with ASTM D4254.
  
  
• Place a 4-inch layer of ASTM No.57 crushed stone as the paver base course once the subbase is completed. Install it in a single lift and compact using the same roller sequence. 

This layer provides primary structural support while also functioning as the main drainage and water storage zone beneath the surface.

Some modern installations use a paver base panel instead of traditional crushed stone for faster installation and improved uniform support.

This Is How The Layer Stack Should Be:

The lay stack in permeable pavers installation is engineered, and each layer offers a distinct function:

• The surface layer for porcelain pavers 20mm, or natural stone 30-50mm, offers the finished traffic surface. 
  
  
• The bedding layer would be open graded no. 8 stone (50mm) for a stable leveling course and offer fast infiltration.
  
  
• For the base layer, no.57 crushed stone (≈100mm) will distribute structural loads and support drainage performance.
  
  
• For subbase layer No. 2 stone (150-200mm +, depending on design) forms the primary structural foundation and stormwater reservoir.
  
  
• A geotextile separator to prevent migration of fines and maintain long-term layer stability.
  
  
• Compacted subgrade with Native soil, properly prepared to support the full pavement system.

Subbase thickness should follow structural and hydrologic design tables from the ICPI PICP manual and ASCE 68-18. The thickness of porcelain and natural stone pavers in vehicular application includes: 50mm bedding and 100mm base. It will remain at a consistent thickness while the subbase depth adjusts for site-specific conditions.

Step 6: Edge restraints

Step 6 is installing edge restraints along all perimeter edges. 

• For porcelain permeable pavers installation, the edge restraint system requires a vertical height of 21/2 inches. It is sufficient to contain both the bedding layer and the lower portion of the 20mm unit.
  
  

• Follow the edge restraint manufacturer’s specific recommendations for permeable applications, including any geogrid usage requirements.
  
  
• Natural stone installation typically uses cast-in-place concrete curbs or precast units set in concrete haunches. The restraints should include at least the bottom half of each surface unit so the system stays aligned under the load shifting. 
  
  

• For heavier stone units, especially the thick granite or bluestones, put more lateral pressure on edge restraints than porcelain. Opt for extra restraint capacity on natural stone vehicular applications rather than defaulting to the residential-grade minimum. 

Edge restraint failure in both material types typically shows as lateral spread at the perimeter, joint gap widening, and loss of surface flatness.

Step 7: Bedding layer

Step 7 of Permeable Pavers Installation is adding a bedding layer.

• Start by moistening, spreading, and screeding ASTM No. 8 open graded stone to a consistent 2-inch depth throughout the base layer. 
  
  
• Use two 2-inch steel pipe guides spaced 6 feet apart to set the screed depth, then draw a straight 2×4 board across them to create a flat and even surface.
  
  
• Fill voids left by removed pipes with additional No. 8 stone. The surface tolerance of the screeded bedding must stay within ±3/8 inch over a 10-foot straightedge.
  
  
• Once leveled, do not allow foot or vehicular traffic on the bedding layer before pavers go down. Even light loading compresses the open-grade stone and creates low spots that will then require full re-screeding to correct. 
  
  
• When using natural stone with irregular thickness tolerances for bedding layers, it can absorb minor unit variations better than dense-graded sand.  

This is another reason why sand should never replace an open-graded aggregate permeable bedding course. It loses permeability from the permeable pavers installation almost immediately under traffic.

Step 8: Laying the pavers

Step 8 of permeable pavers installation is laying pavers. 

• Now starting from the lowest corner of the installation area. For porcelain paver installation, install a 4mm plastic spacer at every paver’s corner before placing the unit alongside. 
  
  
• Two porcelain pavers shouldn’t touch directly, which is why the spacer maintains the drainage gap consistently.  It also absorbs minor thermal movement through the surface. For every 100 square feet, approximately 34 spacers are needed.