Excerpt from Riding Arena Footing Material Selection and Management [Full Article PDF], Penn State University
Riding Arena Surface
Unfortunately, there are no universal recommendations for the perfect arena surface or footing material. A “perfect” arena surface should be cushioned to minimize concussion on horse legs, firm enough to provide traction, not too slick, not too dusty, not overly abrasive to horse hooves, resistant to freezing during cold weather, inexpensive to obtain, and easy to maintain. Cost of footing materials is dependent on local material availability and transportation expense. The intended use of the arena for jumping, reining, or driving, for example, also influences footing material attributes such as traction and depth of loose material. Manufactured or trademarked materials are options that depend less on local availability and provide more guarantee of uniformity in material properties. Naturally occurring inorganic materials (sand, etc.) are offered by quarries that can provide raw materials or mixtures that have defined characteristics of particle size and composition.
A handicap to recommending a strict formula for footing materials is that materials vary greatly around the county and country. For example, sand from one location is often very different from sand in another location. Local terms for materials can vary widely and contribute to the confusion. However, it is possible to develop some guidelines and use common sense to get a good, workable footing material. Quarried inorganic materials (sand, stonedust, gravel, road base mix) from quarries can be designated according to standard adopted nomenclature that relates to particle sizes and the distribution of sizes found in the purchased product. Particle size distribution describes a footing material in a “standard” format. The distribution is determined by shaking the footing material through a set of sieves that have increasingly smaller holes so that finer material ends up on the lower sieves while larger particles are held on the upper sieves.
Footing is actually a rather dynamic material that undergoes compositional and property changes with time and use. Almost all arenas will have manure “naturally” mixed in over the years and the result can be a good, workable footing that no longer has a simple description. In addition, footing materials break down from the impact of horse hoof action. In some cases, the arena surface started as one material that broke down into smaller particles or compacted over time. As older material breaks down, these arenas are topped off with fresh material that may be different to support or renew the property that was lost. Many successful arena surfaces start out as a composite of two or more materials.
Regardless of type, most arena surfaces will need amendment at least every couple of years since arena footing material does not last forever. Every 5 to 10 years, plan on a complete footing replacement or at least a major overhaul. Even with proper management, the best, most carefully selected footing materials rarely maintain their good attributes indefinitely. The key is to learn to manage what you have at all stages of its “life.”
This bulletin focuses on arenas that have a moderate to high amount of horse traffic, such as at a commercial facility. A private backyard arena, used once or twice per week, would be exposed to much less wear and tear and may suffice with a simple arena design. Most importantly, it has been proven that a successful arena surface is no better than the underlying foundation of base and subbase it rests upon (Figure 1). A good indoor or outdoor arena surface is just the top layer of a multilayer composite. The base material is hard-packed material similar in construction to the base supporting a road surface. See the Additional Resources section for publications with base and subbase layer design criteria for arena construction. The loose footing material discussed in this bulletin is installed on top of this supporting base. The footing needs to “knit” to the base material, meaning that loose footing is not allowed to freely slide along the compacted base as horses work in the arena. Knitting is naturally achieved with some footing material selection and is designed into other footing material installations.
Figure 1. The footing material is only the top layer of riding arena construction and is dependent upon the support of a suitable base and sub-base.
Footing materials used on a farm’s indoor and outdoor arenas may be different. Consider the conditions and use of each arena. For example, the indoor arena may be primarily used during cold-weather months with an outdoor arena used the other seasons. The outdoor arena may have to shed considerable quantities of rainwater and snowmelt with the expectation that most footing material will stay in place, so a well-draining, heavy material that does not float would be desirable. An indoor arena footing mixture that holds moisture longer will reduce the need for frequent watering. The indoor arena surface material may incorporate salt for dust control via moisture retention. Alternatively, a wax, polymer, or oil coating may be added to reduce dust.