Which Base Course Materials Are Best for Porous Pavers?

Suitable Materials to Consider for Porous Pavers:

Sandy gravel’s well-graded particle size offers good drainage properties

Often sourced from local quarries, sandy gravel has well-graded particle sizes. This offers good drainage properties that allow water to infiltrate easily. Plus, its coarse nature provides stability, making it suitable to support the load a porous paving can be subjected to.

Crushed stone aggregate supports all functions of a porous paving system

Widely used as a base material for porous pavers, crushed stone aggregate is versatile and available in various sizes. It provides excellent drainage performance, stability and load-bearing capacity to a porous paving system.

Open-graded aggregate promotes rapid water infiltration

With minimal fine grain size, open-graded aggregate promotes rapid water infiltration. This makes it well-suited for areas with high water flow. Locally sourced open-graded aggregate ensures compatibility with regional soil conditions and enhances the overall porosity of the porous pavement system.

Materials to Avoid for Porous Pavers

Regular sand does not provide a stable surface for a base course

While sand is often used as a base for traditional paver installations, it is not ideal for porous pavers because of the lack of stability, especially in that it lacks the load-bearing capacity required for areas with vehicular traffic.

Clay Soil retains water causing poor drainage

Clay soil has poor drainage properties and tends to retain water, making it unsuitable for the porous nature of these pavements. Using clay soil can cause pooling on the surface instead of allowing water to infiltrate into the ground. Moreover, the material is prone to expansion and contraction with changes in moisture levels. This can compromise the stability of the paver system.

Recycled concrete fines can clog the system

Recycled concrete fines is produced by the crushing of concrete. Due to the nature of the process, the aggregate is very likely to contain excessive fine materials. These fines can lead to clogging and reduce the porosity of the porous pavement over time. The uneven particle sizes may also result in an unstable base, affecting the overall performance of the porous pavers.

Topsoil’s organic matter compromises stability of the porous paver

The organic materials in the topsoil can break down over time, causing settlement and compromising the stability of the paver system. Additionally, topsoil’s fine texture can impede water drainage, defeating the purpose of using porous pavers for effective stormwater management.

Crushed limestone with fines can impede water movement

Limestone solidifies over time, reducing the porosity of the base and impeding water movement in the porous paving system. But if limestone is the most readily available stone in the area, there is a way to use it as the base course material. The combination of limestone mixed with 30 percent sand prevent solidification and loss of porosity.