How Much Polirock Binder Do I Need for Stone Depths?

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How to Calculate Polirock Quantities for Your Area and Stone Depth

Planning a resin-bound stone surface outdoors? It’s crucial to work out how much Polirock binder and aggregate you’ll need, based on your project area and chosen stone depth. Getting the calculation right helps you avoid waste and ensures a durable, attractive finish.

Basic Quantity Calculation: Area & Stone Depth

For permeable outdoor surfaces using Polirock, the ratio of binder to stone is a key consideration. As a guideline, approximately 432kg of clean, dry aggregate and 13kg of Polirock resin binder will cover about 1.44 square metres at a 20mm depth. This works out at a resin-to-stone rate of roughly 3% by weight. Always round up your estimates to accommodate for uneven surfaces or intricate areas.

How to Adjust for Different Project Sizes

To calculate for other surface areas or stone depths, multiply:

The area in square metres by your chosen stone depth (convert mm to metres for depth calculations).
Use the 3% resin-to-stone weight ratio to determine binder needs.

For example, if your project area is 5m² at a 20mm depth, you’d need around 1,500kg of aggregate and 45kg of Polirock resin. If you are using washed pebbles, check quantities based on the bag size.

When This Matters Most

Accurate calculations are especially important for larger courtyards, high-traffic patios, and any area where a uniform finish and lasting performance are needed. Underestimating materials can lead to weak spots, while overestimating increases cost.

Related guides

What Aggregate Should I Buy For Courtyards

With the right approach to Polirock and aggregate quantities, your resin-bound courtyard will look professional and last longer. For more aggregate options and expert advice, visit our main guide on what aggregate you should buy for courtyards.