Horse arena footing consists of many more components than the top, visible sand layer. When building a riding arena, the base is a very important part of the arena footing. However, it is often overlooked! Choosing the correct arena base material is imperative in building a functional indoor or outdoor arena. Therefore, consulting a professional who is experienced in building horse arenas is important.
What are the Types of Arena Base Construction?
There are two types of arena base systems on the market. These are vertical drainage systems and the common arena base, which relies on surface drainage.
Outdoor Arena Options: Vertical Drainage vs. Surface Drainage
Vertical Drainage Systems will never stop you from riding.
A draining base system is an investment that allows you to keep riding in your horse arena even during and after very heavy rains. The permeable composition of this arena base can be built with either HIT DrainGrids or EURO Arena Mats. These bases are placed on top of a layer of drain rock/gravel, then finished with the arena sand and sand additive. An arena base with a vertical drainage system guarantees a lifelong horse arena. And, it will save you a lot of money and maintenance in the long-run.
A common arena base provides surface drainage.
If you are NOT dependent on your outdoor arena for riding after heavy rains, then a common arena base with surface drainage is customary. With surface drainage, you will need to allow 2-3 days of drying up of the surface after heavy rainfall.
On top of your compacted natural soil, which is the sub-base, goes the arena base aggregate. This is typically 6 inches of a compacted crushed rock or limestone topped with 2 inches of decomposed granite or stone dust compacted to 98% proctor (density).
Selecting the right arena base material is as important as selecting the right arena sand! It is crucial for the longevity of the arena base and the horse arena footing. Stay away from aggregates that have a lot of fine particles, like silt and clay. These aggregates will compact easily. However, soon after a rainy season, the fines from these aggregates will migrate into the nice, clean silica sand. This will contaminate it, inhibiting the drainage and changing the characteristics of the arena footing. Likewise, when too much clay and silt migrates into the clean arena sand, over-compaction of the arena footing will occur.
Prepping for Your Outdoor Arena Base Layer
For both arena base options, you need to grade and compact your natural soil at 1-2% grade, and cover it with a permeable landscape geotextile fabric in preparation for your arena base. The non-woven geotextile fabric will ensure that the clay particles from your natural soil are not entering into your base layer and inhibiting drainage in the long run.
Indoor Riding Arena Base
The base for an indoor riding arena is rather easy and straight forward to build. You will level and compact the existing natural soil, then add 4-6 inches of stone dust or decomposed granite compacted at 98% proctor (density). Using EURO Arena Mats or drain grids will add concussion absorption and extra shear strength from the arena base up.
Irrigation from the Base-Up
There are two proven base systems on the market that water the horse arena footing from below: the HIT UnderGround Watering System and the Ebb and Flow System. Both implement irrigation and drainage technology simultaneously, while working with the capillary effect of sand. The capillary effect draws the moisture up into the horse arena footing. Each option has its place in the world of underground watering systems. But, they work identically when it comes to providing even moisture in the arena footing while saving water and preventing evaporation.