Sand is the general term for the broken down granules of rocks. Sand is smaller than gravel, but larger than silt or clay. Over 10,000 different sand names are used in the U.S. alone. It is very important to understand the qualities of the sand and not go with just a name.
Why is the right sand so important?
Sand is the key ingredient in all good arena footing and additives; however, not every kind of sand is suitable for all riding arenas. Sand that is well suited for a highly-maintained indoor riding arena might be completely unsuitable for an all-weather, low-maintenance outdoor riding arena. Choosing the wrong sand can create problems and be very expensive over time. The following are some factors to help you choose the right sand.
Sand is classified by its size rather than what type of mineral it is. Particle size, or grain size, refers to the diameter of a grain of granular material. Particles that fall between 0.42 mm and 2 mm in diameter are referred to as ‘sand’ (see chart). Most sand has a variety of particle sizes from large to small, known as a gradation. Sand gradation is measured by vibrating a sample through a set of known mesh sizes (large to small). The percentage of sand that passes each numbered sieve is measured to create a sand gradation report. Higher sieve numbers equal smaller grain size, lower sieve numbers equal larger grain size. Most sand producers will have prepared gradation reports for the different sands they sell. This information will help you determine exactly what type of sand you are buying. It will also determine how the sand will perform alone or with a footing amendment.
Important: The sieve size range to look for will depend on what type of additive you are adding, or if you want a sand-only arena.
The sand’s particle shape affects how the grains nest together. This affects stability underfoot.
Round particles create voids, which offers cushioning. However, they are typically unstable and can roll like ball bearings. This decreases stability and traction.
Angular particles have sharp edges and fit together tightly. This provides stability and traction, but angular particles can compact and become hard.
Sub-angular particles have the sharp edges worn off. They will nest while still allowing some movement. This lessens compaction and provides traction.
Grading is a representation of different sized particles. This affects how much the sand compacts or remains loose. Sand with all the same size particles will remain loose, may become shifty, or feel deep. Sand with equal amounts of differing sizes will nest and compact. A happy medium range of large to small particles will help keep your footing firm, but not compacted.
Keeping your sand particles graded is an important part of maintaining your footing. A professional type groomer is key. Our unique line of Premier Groomers will ensure a properly mixed, leveled, and stabilized surface with high performance results.
Where does sand come from?
Natural Sand: Natural sand has eroded from mountain rock and is mined from where it was deposited. The host rock determines the exact mineral composition, but most sand is composed of silica from broken down quartz crystals. This type of sand is extremely resistant to weathering and breakdown due to its chemical hardness and will last longer as arena footing. These hard sand particles have been transported and tumbled by water, making them round or sub-angular in shape.
Manufactured Sand: Rock quarries crush rock into various sizes. The smallest particles are called fines and are sold as ‘manufactured sand,’ ‘man-made sand,’ ‘crusher fines,’ or ‘stone dust.’ These particles range from 5 mm to fine dust, are sharp, and will tightly compact if used alone. The mineral composition can range widely. These particles are not the hard quartz grains of tumbling river action, so they may be softer and break down to dust sooner. These sands have very sharp tendencies. A small amount of manufactured sand can be useful to add stabilization to rolling footing with very round sand grains.
Quarries across the country will have different names for their types of sand. Mineral, particle size, and gradation will vary. Be sure to use the specifications and sizes to determine what sand you will need and not the name of the sand, as “Arena Sand” could mean anything. These are sands you’ll commonly find:
Pit Run: Sand excavated and sold “as is” without grading or washing is called Pit Run. It will have a wide variation from large grains to dust fines and the sand deposit, which may vary within the quarry, determines the properties.
Washed Sands: Getting a sand that is washed of all fines (dust) will not be as stable of a surface as a sand that contains some fines (below #200 mesh or sieve size). Washed sand will have less dust, but it will also have less traction, less compaction, and less shear strength (the horse’s hoof going through the surface). Be careful when choosing washed sands. If you have water available, unwashed sand may be a better option. Be sure that the particles that fall below a #200 sieve do not exceed 10% or dust and compaction may be an issue.
Fine Sand: This sand’s particles range between 0.42 mm – #40 sieve and 0.074 – #200 sieve (40/200). Fine sand mixes well with textiles and binds loose sand, but should not be used alone. Fines, clay, and silt can create dust and compact.
Masonry Sand: This particle shape can vary from round to sub-angular. Particle size for Masonry sand ranges between 0.60mm
(#30 sieve) and 0.15mm (#100 sieve). Masonry Sand is a standardized size specification and is washed but contains some fines. Masonry Sand is widely available and mixes well with crumb rubber products such as Prostride Arena Footing.
Concrete Sand: Particles are usually sub-angular to angular in shape and tend to be larger in size. The particle size ranges between 2.0mm (#10 sieve) 0.3mm (#50 sieve). Concrete Sand is a standardized size specification and is washed but contains some fines. Like Masonry Sand, Concrete Sand is also widely available and will mix with crumb rubber.
Note: All of these sand types will have benefits as well as potential pitfalls. To verify the integrity of the sand you currently have or want to use for a new project, be sure to contact one of our footing specialist prior to choosing a footing amendment.
Unfortunately, you are somewhat limited to using a material that is located in your area, as trucking sand in from long distances can be extremely costly. Premier Equestrian can help you and your contractor determine what sand in your area will be right for you. This is where footing additives can help solve many of the dilemmas associated with local sand.
LET US HELP
We love to talk about sand. Contact a Premier Equestrian footing expert at 800-611-6109 or fill out our footing contact form online