As an approximate guide, one bulk bag will cover:

• 10–12m² at a depth of 50mm

• 6.5–7.5m² at a depth of 75mm

• 5–6m² at a depth of 100mm

Garden paths, borders, and decorative areas commonly require around 40mm to 50mm of gravel, while domestic driveways typically require approximately 50mm to 75mm to provide a stable, long-lasting surface.

These figures are estimates only. Actual coverage will vary according to the bag weight, ground conditions, compaction and the accuracy of the excavation.

Not sure how many bags you require? Call our Rugby team on 01788 866945 with the length, width and required depth.

20mm gravel is intended as a decorative surface, drainage, or pipe bedding material. Colour, shape, and appearance can vary according to the source of the aggregate.

Excavate the area to the required depth and prepare the ground appropriately. A suitable geotextile membrane may be required to prevent weed growth and stop the subgrade from mixing with the aggregate.

 

Spread the 20mm gravel evenly over the prepared sub-base to the recommended depth, typically around 40mm to 50mm for borders and footpaths, or 50mm to 75mm for driveways. Rake the gravel to ensure an even distribution across the entire area.

 

Check the finished surface level and slope to ensure proper drainage away from surrounding structures. Ensure the gravel depth is consistent to prevent exposed patches or uneven surface layers.

 

Requirements vary according to ground conditions, loading, and the intended use of the surface. Follow the project specification or seek professional advice where appropriate.

Available for collection from our Rugby branch or local delivery using our own fleet.

Bulk bags will normally be delivered by a crane-equipped lorry. Delivery is kerbside and the final offloading position is always subject to safe access and the driver’s discretion.

Please tell us before delivery about:

• Narrow roads or restricted entrances
• Parked vehicles or limited turning space
• Overhead cables, trees or other obstructions
• Soft, sloping or unsuitable ground
• Any other access concerns

Enter your postcode on the product page to check your delivery area. We’ll confirm the delivery date after your order is placed.

What is 20mm gravel?

20mm gravel is a medium-to-large angular aggregate, typically composed of crushed natural stone, quartz, or river shingle. Its 20mm size makes it versatile, durable, and easy to walk or drive on without shifting excessively.

What is the difference between 20mm gravel and 10mm gravel?

20mm gravel features larger stones that interlock better, making it ideal for driveways and high-traffic areas because it stays in place and won't get stuck in shoe treads. 10mm gravel has smaller, smoother stones preferred for decorative borders, delicate footpaths, and pipe bedding.

Is 20mm gravel suitable for driveways?

Yes, 20mm gravel is considered the industry standard size for gravel driveways. It is large enough to prevent stones from becoming lodged in car tire treads, yet small enough to create a firm, level surface for vehicles.

Does 20mm gravel drain well?

Yes. Gravel is a naturally permeable material, making 20mm gravel an excellent choice for Sustainable Drainage Systems (SuDS). Water drains freely through the gaps between the stones, helping to prevent standing water and surface flooding.

Do I need a weed membrane under 20mm gravel?

Yes, installing a geotextile membrane underneath the gravel layer is strongly recommended. It prevents weeds from growing up through the stones and stops the gravel from sinking into or mixing with the sub-grade soil over time.

Why does the color of 20mm gravel vary?

Gravel is a naturally quarried product, so its appearance, tone, and texture depend entirely on the geographic region and rock source (such as granite, limestone, or flint). Stones will also appear darker and more vibrant when wet compared to when dry.