Drainage Gravel 5-7mm

5–7mm Drainage Gravel is a small gravel that is commonly used for:

• Backfilling around drainage pipes
• Drainage behind retaining walls
• Soakwells and drainage pits
• Planter boxes and pots
• Garden drainage
• Around AG pipe in French drain systems

Its uniform appearance makes it a popular choice if you want a drainage solution that also looks aesthetically pleasing.

Yes, 5–7mm Drainage Gravel is suitable for use in French drain systems. It provides excellent water flow and helps filter sediment around slotted agricultural (AG) pipe and Bidim filter cloth.

To calculate how much 5–7mm Drainage Gravel you need for your project, measure the length and width of the area where the gravel will be placed.

Next, determine the desired depth of the gravel. The required depth will vary depending on your project and the area you need to fill.

Once you have your length, width, and depth measurements, you can use our cubic metre calculator above or calculate the volume manually using the following formula:

Volume = Length × Width × Height

Note: We recommend adding at least 10% extra to your total calculated volume to allow for settling and levelling.

While not essential for every project, we highly recommend using Bidum filter cloth (geofabric) and AG pipe alongside your drainage gravel. The geofabric helps prevent soil from washing into the gravel, while the AG pipe efficiently collects and carries water away. Together, they create a more reliable, longer-lasting drainage system and help reduce future maintenance.