Construction of Equine All-Weather Paddocks for Mud-Free Management (2024)

Introduction

This article describes the construction of all-weather paddocks, also known as "heavy use areas," for horse turnout in corrals, pens, or yards. Another common name for this all-weather space is a sacrifice paddock since the grass is "sacrificed" to be a non-grassed area for equine exercise. These paddocks are frequently used as a central feature of a rotational grazing layout. Part 1 of this series, Mud-free Turnouts on Horse Farms, provides reasons for including an all-weather paddock in farm planning along with features such as location, fencing, and maintenance for horse farms.

A good example of individual all-weather paddocks (photo credit: Eileen Fabian)

A good example of a group all-weather paddock (photo credit: Laura Kenny)

Even with large pastures, lush with grass, there can be areas around gates and water or feed stations where the concentration of horse traffic has killed all vegetation, leaving bare ground. Barren areas also develop in access lanes between the stable and turnouts. These bare areas often become excessively muddy for long periods of the year leading to nuisances and environmental pollution (see Part 1).

Horse group housing options at the same farm. The newer turnout option has an improved shelter with a perimeter concrete apron feeding pad and all-weather surface beyond (top photo). The bottom photo option is an unvegetated muddy lot. (photo credits: Eileen Fabian)

Multi-Layer All-Weather Paddocks

A successful all-weather paddock has a multi-layer construction. The cushioned footing surface of the mud-free turnout is an important feature for horse welfare and often the focus of intense discussion and decision. Perhaps more importantly, below that footing is a two-part construction of a packed sub-surface of native subgrade as a foundation for the hard support base layer. These two layers offer stability for a mud-free, uniform surface for the horse. Construction is virtually the same as needed for an outdoor riding arena, albeit for a smaller area.

Subsurface subgrade

The subgrade is the original soil upon which the other layers are constructed, and its integrity highly impacts the longevity and function of the all-weather assembly. All vegetation, stones, roots, and organic matter must be removed from the turnout site prior to the subsurface grading since these inhibit compaction. This site preparation typically results in removal of a 6-to-12-inch (15-30 cm) depth of native material. A highly compacted subgrade is necessary to assure good performance for the all-weather surface above it. It is recommended that the finished subgrade be topped by a geotextile material to increase stability of the installation (geotextile information later in this article). Wet or poorly drained areas are not ideal for this paddock, so choose higher and drier ground. The subgrade should be slightly sloped for drainage, which will be discussed later in the article. Always remember to check on underground utility locations (which you can do by calling 811) before beginning an excavation project.

Surface footing layer

To finish the top of this multi-layered all-weather paddock construction, a cushioned footing surface is often provided for equine comfort. Ideally, choose a material that is compactable with aggregate no larger than ¼-inch (6 mm) in size to reduce the chance of any loose pieces injuring a horse hoof. This finishing course of finer-sized material would be about 2 inches (5 cm) thick when settled or partially compacted. Options for this layer include footings common to outdoor riding arenas. Be aware that inorganic materials (stone, sand, gravel) can cause colic if ingested. Large rubber mats are often placed on these surfaces if horses need to eat hay or grain when turned out. Horses should not be fed directly on a sand surface to reduce the risk of sand consumption and colic.

Common surface choices include:

Limestone dust: Affordable and durable. Dusty due to fine material. Can compact over time to become a very hard surface. May be mixed with other footing materials to reduce settling.
Sand: Affordable, not highly compactable but may contain dusty fines.
Rubber shreds: Provides a very cushioned surface. Often mixed with other footing materials. Can float and be carried away by heavy stormwater.
Pea stone or crushed gravel: Small, rounded stones are less likely to injure hoof soles than sharper gravel. Reduced chance to wash or blow away like fine materials.
Bark/wood chips: Requires frequent topping off as the wood breaks down. Decomposing fines can eventually accumulate to point of being "muddy." It is critical to know where the wood comes from to avoid using black walnut, which can cause laminitis.

Pea stone gravel as a footing option on an all-weather paddock. Photo credit: Laura Kenny

Stability and Drainage

There should be little percolation of water through the all-weather paddock multi-layer construction described here. A properly packed subsurface will have virtually no permeability to water. Once a suitable location is chosen, strong and durable construction is dependent on careful compaction of each layer. A loose support base and subsurface will not properly perform with intensive horse activity or light vehicle traffic. Loosely constructed layers are susceptible to mixing together and, therefore, lose their individual functions, have reduced support for any weight-bearing activity, and eventually become an uneven, potholed area.

Subsurface slope

Subsurface subsoil preparation affects performance. Slope turnout and improved areas to direct surface water runoff to a location that can handle infiltrated water. Development of this slope starts with the subsurface. The all-weather paddock site should be cleared, grubbed, excavated, graded to the appropriate slope, and compacted. The subgrade surface should be free of topsoil, rocks, vegetation, roots, debris, depressions, mud, standing water or frozen/frosty ground. Any necessary fill material should be suitable for compaction (well-graded inorganic material) and placed in lifts (thin courses of material) of no more than 6 inches (15 cm) in depth, compacted with appropriate equipment, then additional lifts added until the desired grade is achieved. It is recommended to work with a professional engineer to design the pad to ensure proper water drainage.

Geotextile fabric

Geotextile fabrics are synthetically engineered materials that were originally developed to improve soil stability and distribute loads over a wider area. Most geotextiles are made from either spun or woven polypropylene material but come in a range of thickness, strength, material, and durability. A 6-ounce (170 g) polyester non-woven spun material is typically successful in all-weather paddocks. A layer of geotextile fabric is placed over the subsurface before adding the support base layer.

Geotextiles perform important functions for the strength and integrity of an all-weather paddock. Two examples of the many types of geotextiles shown here. Photo credit Eileen Fabian.

Geotextiles perform three main functions:

Separation – Geotextile separates the existing subgrade soil from the all-weather support base material and prevents this base material from mixing with the existing subgrade soil.
Load distribution – Geotextile reduces the localized surface loads and redistributes the pressure across the existing subgrade soil to minimize its deflection. Deflections can lead to hoof potholes, tire ruts, and mud holes under load.
Reinforcement – Geotextile reinforces the all-weather surface by providing tension resistance from applied loads, which prevents aggregate separation.

Geotextile fabrics are available in rolls from 8 to 12 feet wide (2.4 m – 3.6 m). Strength characteristics are similar for both spun and woven manufacturing processes with strength designated by Class. The Class I fabrics are stronger and recommended for the highest traffic areas, yet even Class 4 should be sufficient under an all-weather equine surface. The geotextile should be unrolled smoothly over the prepared subgrade so it conforms to the surface face. Slack fabric does not distribute loads evenly over the subgrade. Overstretching the fabric puts the fabric under permanent tension that should be avoided. Overlap joints at least 12 inches (30 cm) to maintain strength and load distribution. Temporarily hold overlaps and edges of the fabric in place with small amounts of support base gravel material prior to installation of the compacted base. Since the ultraviolet portion of sunlight can damage geotextile fabric material, cover the fabric within 48 hours of exposure.

Precipitation

The importance of drainage at the all-weather paddock site must be emphasized. Rainwater and snowmelt must shed from the surface by providing a center crown or slope to one edge, typically at a 1 to 2 percent slope, up to 5 percent. For the small amount of water that does percolate through the surface base, the wicking action of the geotextile moves water laterally out of the all-weather construction to drainage areas more quickly. Subsurface tiling may be needed where water is diverted from the paddock to assist drainage from entering the groundwater or to maintain strength of the existing subgrade soil. Subgrade strength is maximized by staying dry with proper drainage and site preparation to shed water.

Vegetated Filter Area

A grassed, gently sloped area may be used as a filter and infiltration area for excess runoff containing manure (urine and feces) nutrient wastewater. Wastewater flows or is piped to the filter area and spread evenly across the top portion of the filter. As it flows through the soil profile and down the slight slope, biological activity, and adsorption in the soil matrix removes waste materials. Most biological activity occurs in the topsoil layer where aerobic (using oxygen) activity provides for odor-free treatment. Not all soils are equally suitable as some provide rapid infiltration for limited treatment while others are rather impermeable and provide surface run-off. Frozen soil will not act as a proper filter. Get professional help from your USDA-Natural Resources Conservation Service or County Conservation District, for example, for proper filter sizing and design.

The vegetated filter area is a relatively low-cost farm wastewater treatment system. They can be variable in cost, approaching that of a septic system. In size, one rule of thumb is to provide about 10 square feet (1 square meter) of vegetated filter for each gallon (4 liters) of wastewater being handled. The spreading device at the head of the filter strip is important for establishing even flow to minimize short-circuiting wastewater through the area. A settling tank before the filter strip will be needed if manure solids are allowed into the wastewater.

These filter areas need to be well-vegetated before being put to use. Keep animals off the filter strip, as the frequent wet soil conditions lead to the destruction of the sod cover by horse grazing and exercise.

Compaction of subgrade and support layers

The subgrade and each layer of the construction will need to be compacted. Several options are appropriate depending on available equipment. Recommended is a vibratory drum roller applied to each 6-inch (15 cm; maximum) lift of material while tracking over the entire surface three times. Although time-consuming, if the entire area can be uniformly tracked, vehicles with rubber tires providing a two-ton minimum wheel load may be used. Small, homeowner-sized walk-behind compactors only supply enough vibration to compact about an inch (2-3 centimeters) of material and therefore would require considerable effort to properly compact many thin courses of gravel to the desired finished thickness. Before beginning work, realize that compaction is achieved when the well-graded material is moist enough such that a hand-held "snowball" of material can be formed. Therefore, the addition of water may be necessary. Once compacted, the layer will resist attempts to gouge or dig the material. Appropriate compaction for non-structural areas, such as an all-weather paddock, is expressed as 90-95% of standard proctor density¹.

¹ The term "proctor" is the evaluation referred to as the Standard Proctor Test or Standard Moisture-Density Test. Other tests provide similar compaction information. A smooth or vibrating drum or paddle foot drum roller is typically used to achieve a suitable compaction level. The most common method of specifying that the material is "highly compacted" is to require a percent of the maximum compaction that can be attained, such as "95% of standard proctor."

Grids

A grid is a material, geosynthetic or masonry, in an open pore design that confines the material placed within them. Grids inhibit lateral movement and other displacement of materials. Strong grid materials can be placed within the top portion of the support base to decrease this material’s movement in high-traffic areas, such as at a fence gate, a poorly drained area, or where some modest slope would encourage the material to become uneven. Grid manufacturers offer specifics for their installation with several types suitable and durable for equine installations. Examples of commercially available products include Paddock Slab, Lighthoof, and Farm Grid.

Interlocking grid paver example for areas with extra heavy horse traffic or conditions more prone to mud, such as a poorly drained area. Top photo vegetation growing through grid system in a pasture low-lying area prone to water pooling; lower photo detail of the interlocking masonry grid. Photo credits Eileen Fabian.

Sizing the All-Weather Paddock

A recommended size for an all-weather paddock is 1,200 square feet (110 square meters) for a single 1,000-pound (500 kg) horse. Horses turned out individually will need this much area to benefit from any ability to exercise. A reasonable dimension to consider is 40 ft x 40 ft (12 m x 12 m) for a one-horse paddock. A minimum size of 500 ft² (46 m²) per horse (20 ft x 25 ft or 12 ft x 42 ft) is rather small for real exercise but does offer free time outdoors in a mud-free enclosure. For multiple horses, the recommended area is 600 ft² (56 m²) per horse to provide for some exercise. Size the all-weather paddock based on the largest group that will use the site at any time. But realize that at 600 ft² per horse (20 ft x 30 ft), the turnout is only about four times the size of a typical 12 ft x 12 ft (3.65 m x 3.65 m) horse stall. Consider a 60 ft x 60 ft (18 m x 18 m) area for multiple horse turnout. Decide whether the all-weather paddock goal is for some limited exercise, requiring larger dimensions, or as more of a holding area. Consider the age and activity level of the horses and stake out the dimensions before beginning construction to visualize the size of the area.

All-weather paddocks can be sized for group (top photo) or individual (bottom photo) turnout and to provide exercise activity or simply as a more restrictive holding area. Photo credits: Eileen Fabian

The all-weather paddock base layers should be slightly larger than the turnout size enclosed by fencing. Providing a "shoulder" to the turnout surface that extends beyond the fence line by 1 to 2 feet (30-60 cm) will greatly reduce damage to the edges and reduce the risk of being pulled loose by pawing horses. The weight of horse activity along the fence line will be more evenly distributed when the all-weather pad has support beyond the edge of this high activity area. For similar reasons, extending the all-weather pad beyond the highest traffic zone at a turnout gate will increase the longevity of the installation.

A recommendation is to provide a "shoulder" on the all-weather surface beyond the fence line, and in this case between paddock fencing, to prevent surface edge crumbling and digging damage where horses congregate near the fencing and gate. Photo credit Eileen Fabian

Summary

Many horse owners are interested in providing their animals turnout for exercise, even during inclement weather. There is also increased environmental awareness and pressure from regulations to mitigate impact of sediment and nutrients from muddy lots that impact nearby water sources. This article has provided design criteria for the construction of an all-weather paddock that allows for turnout in inclement weather and helps to protect the environment.

Attention to details of site preparation and construction outlined in this article will provide a long-term solution for muddy, rough turnout paddocks. The underlying gravel base support layer is critically important for the proper functioning of the top footing in a mud-free environment. As with any construction, a properly prepared subgrade is the foundation for a successful design. Good drainage of the site and intense compaction of the subgrade and support base layers are essential for long-term integrity of the construction. The addition of a geotextile layer provides more strength and longevity to the all-weather turnout. Drainage of water through this multi-layer assembly will be very minimal. During precipitation events, most water will be shed via the paddock’s slope, therefore, attention to nutrient management for the site is needed. When a cushioning, top layer of footing material is added, it should be compacted with a roller before use. Feed such as hay and grain should not be fed directly on this surface to reduce the risk of footing ingestion. If feeding is anticipated, provide an organic footing and/or use hay feeders situated on rubber mats.

Additional information on benefits to equine welfare, paddock siting, maintenance, and "quick-fix" for muddy paddocks can be found in the other two articles in this series. Meanwhile, the recommended features for a durable, cost-effective all-weather equine paddock for year-round turnout have been featured in this article.

Notes:

This article focused on horse-occupied areas such as turnout paddocks or around gates. Similar all-weather site construction can be used for traffic lanes used by lightweight vehicles (pickup trucks or pasture mowing equipment) and manure stockpile areas. For all-weather vehicle traffic lanes, crushed gravel provides suitable stability, but installations suffer from sharp edges that will result in horse hoof bruising and abscesses. For these areas that also expect horse traffic (but not confinement), one remedy for a rough surface is a shallow top layer of finer-grade material, such as coarse sand or packed stone dust, that can cushion the rough material.
Mud-free Turnouts on Horse Farms, part 1 of this series, contains details on the location and maintenance of all-weather paddocks in addition to benefits for horse health and welfare in having a suitable turnout area.
Options for Quick-fix Mud-free Horse Turnouts, part 3 of this series, offers more easily built, but less-durable constructions, than the recommended multi-layer design described here in part 2. These "quick-fix" options offer lower initial cost yet increased long-term maintenance labor and cost.
Manure management of all-weather paddocks is required. Sources for storage and disposal information includeManure Storage on Horse Farms and Horse Stable Manure Management. Details of applicable regulations, such as those in Pennsylvania, are found here: Nutrient Management Act.

Additional Resources

Mud-Free Turnouts for Horses
- All-Weather Paddock Design: Part 1 of 3.
Options for Quick-fix Mud-free Horse Turnouts
- All-Weather Paddock Design: Part 3 of 3.
Heavy Use Area. Natural Resources Conservation Service 561. [A national Standard on heavy use area construction for animal use the basis of which led to many of the recommendations included in this series of articles.]
High Traffic Area Pads for Horses. University of Kentucky, Cooperative Extension Service.[Similar information to that offered in this series of articles along with photos of horse all-weather surface construction]
Equine Greener Pastures. University of Vermont Extension.[A step-by-step example of how these pads were installed in gate areas at the University of Vermont in 2005.]
Using All-Weather Geotextile Lanes and Pads. 1999. K. Janni. T. Funk and B. Holmes. MWPS AED 45. MidWest Plan Service. Ames Iowa. www.mwps.org[Authored by agricultural engineers experienced with construction of all-weather installations at livestock farms, this bulletin contains more construction detail.]

Thanks to Dr. Danielle Smarsh (Equine Extension Specialist, Assistant Professor Animal Science, Penn State University) for peer review suggestions that improved this article.