What size pebbles are used for permeable floors?

← Back to How Does Permeable Flooring Work?

Choosing the correct pebble size is vital for constructing an efficient and long-lasting permeable floor. The right aggregate ensures both water permeability and resilience, creating a surface that remains durable and safe in all weather.

Recommended Pebble Size for Permeable Flooring

When installing a resin-bound permeable surface, pebbles measuring 4 to 8 mm in diameter are the preferred choice. This size range strikes the perfect balance between leaving sufficient gaps for drainage and maintaining a compact, walkable finish. Using pebbles outside this range can either limit drainage efficiency or make the surface unstable.

Why Does Size Matter for Permeability?

The use of 4–8 mm pebbles allows rainwater to filter through the finished surface into the sub-base below, helping to prevent puddling and flooding after heavy rainfall. This size is ideal for use with specialist resin binders, making it suitable for driveways, patios, and pathways. Proper aggregate choice also ensures the surface can withstand regular foot and vehicle traffic.

Practical Tips for Installation

For best results, opt for pre-washed and dried pebbles, such as those in the Washed Pebbles for Permeable Floors 25kg bag, to promote secure adhesion with the resin. Always match the binder type with your chosen stone colour—use non-yellowing polyurethane for white stones and low-yellowing epoxy for coloured aggregates. Follow the kit or supplier’s recommendations for mixing and laying to achieve a smooth, even finish.

When Exact Pebble Sizing Matters

Selecting the correct pebble size is especially important for surfaces intended for heavy use or in areas prone to water pooling. The optimal 4–8 mm range ensures efficient drainage, structural integrity, and compliance with sustainable landscaping practices.

Related guides

How Does Permeable Flooring Work

Understanding the importance of pebble size helps you build permeable floors that are robust and effective. For a full overview of the technology, see our main guide on how permeable flooring works.