If ratio of diameter of bedding layer to base course layer aggregate is less than 1:10, then no geofabric is required between the layers.
Why? The materials are close enough in size, ensuring that migration of smaller bedding course material into the voids of base course does not occur.
TIP 2 - To avoid clogging of permeable pavers
Ratio of contributing impervious areas to permeable paving area – no greater than 4:1
Image: Concrete Masonry Association of Australia
TIP 3 – Avoid recycled concrete basecourse
Why? The limestone leaches out of the material and clogs the system.
TIP 4 – Always install an edge restraint or a concrete kerb
Why? To prevent movement, ensure load is spread across.
TIP 5 – When design is close to a footing or structure
ensure no water enters the subgrade by:
- ensuring a minimum 1% grade of pavement to draw the water away from the structure/wall
- installing an impermeable liner that redirects water away from the footing.
TIP 6 – Use permeable paving to protect significant trees
even if the tree is on an adjacent property.
TIP 7 – To preserve infiltration capacity
pervious pavement subgrades should not be compacted (Drake, Bradford & Marsalek, 2013).