Getting Started on the Right Footing
Your guide to building and maintaining an all-weather riding arena.
Horse Illustrated September, 2001 By Sarah Christie

Mud in the winter. Dust in the summer. Rocks surfacing all year-round. Anybody who has ever tried to scrape out a flat spot in the back paddock and have an instant riding arena knows the frustration of trying to train without the proper preparation under foot. Riders who must keep their horses in peak condition through the winter dread the sound of squelching. Foul weather makes for foul footing, and that means compromising your training schedule. Riding in cuppy or slick conditions increases the likelihood of pulled suspensories and bowed tendons, not to mention the time needed to clean splattered tack and soggy leg wraps. By contrast, raw soil compacts in the summer, causing greater chance of concussion injuries. Inflamed joints, sore shoulders and even road founder can result from hard training on hard surfaces, not to mention the annoyance of swirling dust. Attempting to soften the surface with manure, topsoil and river sand only makes matters worse. Manure dries up and blows away in the summer, topsoil turns to mud in the winter, and local sand deposits are rarely free of rocks and noxious weed seeds. However, a variety of high-tech, non-toxic additives can easily be mixed with sand or organic materials to enhance the life span and functionality of your riding surface. Combined with proper site preparation and regular maintenance, the pitfalls that plague outdoor arena riding can be avoided.

Size Matters
Building an all-weather arena can be a sizable investment, with costs as much as $2 per square foot. Do the math, and it is conceivable that a 150 x 200-foot arena could carry a $60,000 price tag. Pegi Cilensek, an arena designer from Purcelville, Virginia advises building the biggest arena you can afford. "You don't want to get all the way to the end and realize it's too small," she cautions. "It makes sense to do it right the first time." The type of riding you do will determine what size arena you need. An arena intended for lessons or regular clinics should be larger than one that will primarily be used for individual schooling. Standard dressage arenas measure either 20 x 60 meters (66 x 200 feet), or 20 x 40 meters (67 x 133 feet) depending on the training level. Competition jumping arenas may be as large as 200 x 200 feet. Laurie Gage, owner of Full Sail Farms, a boarding facility in Paso Robles, California, says square jumping arenas are not the best shape. "The way courses are set up, you want a long side for combinations and a short side to set up and control forward motion," she says. "A good, multi-purpose dimension is 100 x 200 feet. That is adequate for most purposes." Round pens also vary considerably in size and construction. Dressage riders prefer a 20-meter (66 feet) circumference, as this is the size of a standard dressage circle. Trainers who green-break young horses favor smaller pens for more effective control and ground work. These pens are usually made of solid plywood walls at least 8 feet high, which slope slightly outward to allow the rider more upper body freedom of movement. Solid walls keep distractions out and attention in, although seasoned horses may get bored more easily in such confined spaces. Because of their relatively small size, round pens can be built with less expense than full-sized arenas. However, their intense use requires more subsurface preparation and maintenance to keep them serviceable.

What Lies Beneath
All you see is a smooth, resilient surface that never puddles. But beneath that heavenly footing are several well-planned layers. No product in the world can turn hardpan or a sunken bog into a nice, fluffy ride overnight if the arena wasn't properly constructed in the first place. In order to withstand weather and long-term use, every arena needs a good foundation. If your arena is simply a flat spot of native soil with no base material or grading, save yourself a lot of time, money and frustration and call a grading contractor before you start dumping new material on it. The equipment and expertise required to excavate, grade, roll and fill an arena makes the process as much art as science. Unless you have a background in this type of construction and access to heavy equipment, it is advisable to hire an experienced contractor. The money you spend up front will likely be saved over the life of the arena, through improved conditions and more frequent use. It always costs more to correct a mistake than it does to do it right the first time. Talk to stable owners in your area to get the names of local contractors, and be sure to get more than one bid. "Typically, older arenas need to be scraped clean, crowned properly and re-compacted," says arena designer Pegi Cilensek. "But sometimes you can get away with spot excavation if you just have a low area that isn't draining properly. Adding new footing and maintaining it can buy you some time before you have to do a total replacement. But I never recommend just dumping in more fill to fix drainage problems." The foundation of any arena is the natural earth sub-base, which must be compacted and graded to shed rainfall. Compacting the base is necessary to keep the native soil from mixing with the added layers above. A 1 to 2 percent grade or center crown is necessary to shed rain and prevent wet spots. Any more than that and you will have the sensation or riding up or downhill. On top of the sub-base, a 4 to 6 inch cap of packed, crushed stone is applied. (Jumping or competitive arenas will need a thicker base, up to 12 inches in depth.) Limestone or decomposed granite are typical base materials. Using material native to your area will reduce costs. This is the layer that protects your sub-base, and it should be packed and rolled to the hardness of asphalt. This, along with a slight grade and a light oiling, will ensure that it sheds any water which drains through the surface layer, rather than allowing it to be absorbed by the sub-base which could lead to low spots and slumping. "Building a base is expensive but there is a reason why," says Jennifer Buchanan, an arena footing specialist with American Rubber Technologies. "There is no cushion out there that will help a poorly draining base. If you have a poorly draining arena, there is something wrong with the base." Over the compacted base, apply a 1 to 2 inch layer of sand. Sand is not an ideal riding surface on its own, but it is an important ingredient in a good footing mixture. "Sand gives you the illusion that it is absorbing impact when in fact it is simply shifting underfoot," says Jennifer. "It provides stability when used with other products, but used alone it breaks down and creates problems." A good quality, coarse material such as washed plaster sand will not pulverize and turn to dust as easily as river sand. Only after proper site preparation should you apply the final surface material. Thanks to recent innovations, you'll have dozens of different products to choose from. But regardless of the material, it should be added cautiously, about 1/2 an inch at a time, to achieve optimum performance. An overly deep riding surface can cause athletic injuries, and it is much easier to add more material than to remove excess. "Too much of a surface can be as dangerous as riding your horse on concrete," says Jennifer. "Cushioning too deep is just as bad as rock-hard footing."

Water, Water Everywhere

Never ride in an arena with standing water. Not only is it unsafe for your horse, it can damage the base and worsen the situation. Puddles indicate underlying soft spots. Punching down through the sub-base mixes native soil and clay with the riding surface, further impairing drainage. If hoof prints are more than 1 1/2 inch deep, the footing is too soft and should not be ridden on. Every arena requires regular maintenance to keep it functional year-round. Depending on the amount and type of use, weekly, monthly or quarterly harrowing is an important routine. Harrowing mixes the footing with the sand below, keeps the surface even and prevents compaction. This is particularly important before the winter rains, as uneven surfaces erode more easily. If standing water is a chronic problem, you can accelerate the drying process by working the surface with a harrow or a drag, and adding an absorbing agent. The absorbing agent should be applied first, then worked into the surface to speed evaporation. Standing water may be caused by inconsistency of surface material. If this is the case, then dragging the arena will also address the underlying cause of the problem. If the puddles are caused by failure of the base, then more extreme measures (excavating) will be required. The ideal winter riding surface is deep enough to absorb concussion, but not so deep as to get heavy. The material should drain well, provide traction, and resist compaction. "Check for bare spots in the fall," recommends Pegi. "If you need more footing, this is the time to bring it in. Then make sure it's harrowed well so you won't have any pooling. You've got to pay attention to maintenance and make adjustment as needed." Jennifer points out that organic materials in particular may need to be augmented after a summer of hard use. "Wood based products break down and compact more quickly than a synthetic, which means less drainage," she says. "If you use a wood product, make sure you replenish with new, undecomposed product before winter sets in." Shredded or chipped wood products are best in areas of lesser rainfall. Because they mix well with sand and hold moisture naturally, they provide an even, consistent, springy riding surface between periods of rainfall. Tom Mower installs arena footing throughout the state of Florida. "It is very forgiving," he says of the wood surface products. "Some synthetics don't hold any water at all, and that can cause problems in drier parts of the country." For areas prone to freezing in the winter, a shredded, pelleted or chopped rubber based footing is a good choice. Rubber is inert, it maintains its resiliency even in low temperatures, and will not freeze since it does not absorb water. If your arena has wood chips or native soil in the mix, anti-freezing agents can be applied in very small amounts to 'winterize' the surface. These salt-based products lower the freezing point of water within the footing, in much the same way that rock salt keeps roads from icing over. It also causes the footing to require less water application in the summer months for dust reduction. Products designed for arena use are substantially less toxic than road salt. Even so, it is advisable to oil your horse's hooves prior to riding in a 'salted' arena, and sponge off his legs afterwards. Arenas in locales which receive a lot of rainfall but are not prone to lengthy freezes may benefit from the addition of an absorbing agent, such as shavings, sawdust or a super absorbent commercial polymer. This is not a substitute for good drainage, but it will slow the rate of runoff, minimize standing water, and provide additional protection for the sub-base. In the summer, you may find yourself wishing for that rain you were cursing six months ago. Sprinkler systems can be an effective way to control dust, but water is a scarce (and expensive!) commodity in many parts of the country. In addition, it takes time to apply enough water to soak in deeply enough to be effective. Sprinkler heads should be installed to provide complete and even coverage, and sized to meet the water pressure requirements of your plumbing system. The good news is products that absorb winter rains also control summer dust, reducing or eliminating the need for sprinklers. Even though rubber products don't absorb water, they act like mulch, holding moisture in the ground and trapping dust. Wood based materials and some synthetic materials do absorb water, and lengthen the time needed between applications. Watering early in the morning and when there is little or no wind will slow the rate of evaporation, and keep your ride dust-free for longer. Your arena is a dynamic system, and a vital part of your training regimen. A good riding surface is important to your horse's health and comfort. If you plan ahead and provide adequate maintenance, it will deliver a winning performance year-round.

The author is a freelance writer, endurance rider and works as a legislative coordinator for the California Coastal Commission.