Image of pile of dirt

Structure of Arena Surfaces

The footing is comprised of the following three layers (Figure below).

Top: The actual riding surface. This layer is lighter, less compact, and can be composed of many different primary components and additive combinations. Depending on use, this layer is often two to six inches thick. Base: The solid, compacted layer between the sub-base and the top layer. Usually, this layer is six to eight inches thick, depending on arena use.

Sub-base: The lowest part of the arena surface, usually made up of the existing soil structure or added rock to promote drainage. The sub-base can include multiple layers.

The crown is a raised area in the middle of the arena that promotes drainage to the sides and outside of the arena. Crowns are only necessary in outdoor arenas, due to variable rainfall. The suggested slope for the crown is 1 to 2 percent. Outdoor arenas can be built with either a crown or with an elevated, well-drained surface. Crowns are often used in arenas with less permeable surfaces to eliminate ponding of water. The crown is typically developed during the initial earthwork and is present in both the sub-base and base layers. A crown will affect maintenance protocols; one must be sure not to damage the crown by not crossing over the center of the arena and by dragging from end to end whenever possible.

Footing Materials


Sand is a very common footing material due to its availability, durability, and drainage capacity. It is a granular component; often described as broken-down rock particles characterized by size, shape, and composition.

Particle Size: Sand particles can be broken down into fine, moderately coarse, and coarse particles. Most arenas utilize coarse sand to promote drainage and reduce dust concerns.

Shape: Particles are either angular or rounded (Figure 2). Shape is often a product of the weathering mechanism that acts to shape the grains of sand. More angular particles pack together easily; rounded particles remain spaced apart.

Composition reflects the origin of the sand or mineral particle (location and geologic layer) and affects the durability of the sand. The most common origin rocks for arena use are sedimentary (commonly known as limestone), quartz (found in igneous, metamorphic, and sedimentary rocks), feldspar (found in both igneous and metamorphic rock), and river rock (mineral composition dependent on location).

Image showing variations of sand angularity and sphericity.
Experimental characterization of the evolution of ballast grain shape and roughness – Scientific Figure on ResearchGate.

The primary type of sand used in arena footing is mineral sand, which is formed by the weathering of igneous, metamorphic, or sedimentary rocks.

River sand: Sand sourced from riverbanks and riverbeds. It is usually of varying origin, and this variance depends on the location of the river source. River sand particles tend to be rounded, as they are smoothed by the action of water sweeping particles downstream over time.

Silica sand: A type of sand composed of quartz, which tends to be very hard and resistant to breakdown.

Class I sand: A limestone-based sand. Can be an inexpensive option but will be softer and less resistant to breakdown.

Crushed Rock/Construction Aggregate

Crushed rock or construction aggregate is more common in outdoor arenas because it can be very effective at draining water. It does not compact easily if it is poorly or uniformly graded, but well-graded mixtures can be compacted. This tendency for crushed rock to become compacted is dependent upon the size, sorting, and gradation. The characteristics of crushed rock are similar to that of sand in the variation of size, shape, and composition. Often, crushed rock or construction aggregate is used as the sub-base or base for the footing.


Rubber is often seen as a footing additive, but some choose to use it as a primary component. As a primary component, crumb rubber or shredded rubber can have relatively little dust. It is believed to increase shock absorption, which is a common reason it is used as an additive to the primary component. It has a low freezing point, which is beneficial in cold climates where riders want year-round arena usage. Rubber is also affordable. Rubber is commonly sourced from recycled materials. The source is especially important when the rubber is a recycled material, as it can potentially contain toxins or even metal particles. It is important to determine that the recycled rubber used as a footing material does not contain any materials or additives that may pose health concerns for horses or humans. Rubber will break down with time, as will any primary component, but it can last longer than other materials.

Soil Mixtures

Soil is a highly variable material that refers to a mixture of sand, silt, and clay. The mixture within the soil can vary greatly and is dependent on the soils that are regionally available. High proportions of clay in soil tend to produce a footing that is slippery when wet and solid and hard when dry. It is highly compressible, making the management of compaction important. Loam is simply a specific blend of sand, silt, and clay, usually with a lower percentage of clay and higher capacity for holding water.

Image showing the different variations of soil possible as a result of mixing clay, silt, and sand.
Soil is composed of silt, clay, and sand particles.

Wood Chips

Wood chips are a softer footing material that can provide a lot of cushion. Wood chips retain water well but break down relatively quickly and thus pose dust concerns. As a primary component, wood chips require a greater amount of water for dust suppression, which can contribute to freezing in cold climates. Riders in certain disciplines prefer this surface because it tends to be softer. It is generally considered a more affordable option for arena footing.

Common Additives


Fiber is added to arena surfaces to add stability, to cushion the surface, and to increase the lifetime of the footing. The fibers act similarly to the root system of a plant in soil, which prevents erosion and gives a firmer surface. Fiber can also promote proper drainage of water throughout the footing material. Fibers are said to increase the shear strength of footing, meaning that the addition of fiber to a primary component will increase the primary component’s resistance to force.


While sometimes used as a primary component, crumb or shredded rubber is also incorporated into other primary components as an additive. Adding rubber can reduce compaction and concussion and increase drainage.

Crushed Rock/Construction Aggregate

Adding crushed rock as an additive can help promote drainage of the primary component, reduce compaction (depending on particle size), and is dependent on many of the factors discussed above (size, source rock, etc.).


The primary component of arena footing will break down over time with repeated concussion from the working horses as well as the addition of organic material (manure, bedding, and mud) over time. Even with manure removal, some degree of organic material will be introduced into the footing. Stronger sands may hold up better, and additives will increase the longevity of arena surfaces, but all surfaces will eventually break down. When this happens, it is usually best to add more footing to refresh the surface, or to replace the surface entirely, depending on the state of the primary component and additive. As the primary component of arena footing breaks down, dust often increases in the arena.

Different footing types also wear differently on arena maintenance equipment. Different types of hard sand and gravel can degrade arena equipment, especially with the frequent use required by arena surfaces. Tines and teeth should be monitored regularly to determine any necessary changes in depth setting or required replacement of parts.

The ideal surface for any horse depends on many different factors, such as discipline and environment. Because arena surfaces continually change with use and maintenance, it is important to evaluate the current footing and adapt the maintenance protocol to suit the needs of the horses using the arena.

Exerts from University of Kentucky Cooperative Extension Service: Riding Arena Footing: Materials and Characteristics (ID-265)