I’m looking to do some work to my current outdoor arena. I’m working with a 180x80 spot that I’ve been riding in for the past 10 years. Not positive on the soil but i believe it’s some type of clay. Right now I just work up the dirt and typically it’s fine in the summer however after heavy rains I can’t use it for days at a time. My plan it’s to re-crown the arena, roll/compact it, add a layer of geo, then 4-6 inches of asphalt millings. I plan on compacting the milling and then adding 4-6 inches of some type of sand. Will this be good to ride on? My main goal is to get something that will drain good so I can ride year round and don’t have to spend a week waiting on the arena to dry. I also may put some drain pipes underneath everything to help as well. I’m just torn on the millings. It would save me THOUSANDS of dollars due to the size of the arena. As long as I have enough footing on top will I be okay to use the asphalt millings?
I think millings will migrate up into the footing unless you add a layer of smaller rocks between the millings and the sand.
I know products vary greatly by region. Maybe what’s sold as asphalt millings in your area is way different than what’s sold as asphalt millings in my area.
Have you consulted an excavation company who builds arenas? There are “many tricks of the trade” in building well-draining surfaces. French drains around the perimeter, drain tile under the arena surfaces, can move a lot of water for you, along with crowning the area.
Personally, I would never use asphalt under the ground because it is oil based, affects the runoff water forever and probably lots of other things we don’t know about. Might make your property difficult to sell. Years ago I knew a person who added rubber shreds to her indoor arena footing. Over the years it got tracked everywhere on the farm. She had to remove ALL the rubber on property to sell. HER responsibility to remove, could not sell without removal.
Cost for removal about equaled what she did sell the farm for. Nothing left for another home in her aging years. Rubber was deemed “toxic waste.” Weird but true!
We have used a quantity of crushed cement for our “hard base” when needed. Cheaper here than limestone or other crushed rock products.
Lastly, don’t make a really deep sand topping on the arena. Deep sand is hard on soft tissue in the legs. Horse needs hoof to get a firm base for push-off with hoof. So less sand, 3 inches or so, is MUCH better than 5-6 or more inches. Less tiring, less strain when horse is tired, when going around the arena. Try running in someone else’s arena with deep footing. Or on a dry sandy beach. Then compare ease of running on harder, wet, packed sand where you can push feet off easily. My Farrier husband saw so many leg problems develop using deep footing in arenas of barns he worked at.
Get an expert in to help you in reworking your arena. It will save you money, redoing things later. Our outdoor arena is usable right away unless we get 4 inches or more rain. Even then it is pretty usable by the second day after such a rain.
I know it’s hard without knowing 100% what my soil is comprised of but is there a general rule of thumb for this? I have not talked to a profession arena builder because we have dozers, graders, skid loaders and will be doing the work ourselves. My sub base seems pretty hard, in the warm summer months in PA my arena gets so hard that a set of discs won’t work it up. Am I better off putting down fabric, then screenings, then my footing? Any tips would be greatly appreciated. I was under the impression that I wanted my base to be concrete like, which is why I thought compacted asphalt millings might work and be cheaper. I believe I’m looking at roughly 400 tons to get a 4-6” base of whatever I decide to use.
I have limestone screenings as my base for both the indoor and outdoor. We tried to use asphalt screenings for the driveway- it was supposed to be double milled and very fine. It was AWFUL- inconsistent in quality. Some of it was final ground and some had pieces as big as a softball. I wouldn’t use it for anything ever again.
I was looking into putting something down this spring in our outdoor round pen and came across this hardness scale for different types of sand. Does anyone know how accurate this is? If someone can verify this, I hope it’s helpful, OP. 
Would you mind sharing your budget? What is the greatest amount of money you are willing to spend.on this project, in other words.
I have an arena just about 20 feet larger than yours and the angular sand needed to spread a layer 4 inches thick is astronomical for me - over $50K just for sand delivery. But I live a round trip of 160 miles from the sand source, and trucking mileage would eat me alive. This example illustrates differences in availability and transport from one person’s arena site to another’s arena site.
This is why a “dirt professional” can listen to what you want, hear the issues you have with present arena after rains, assess the ground in question, to draw up a final plan for you. Such a plan will say if the concrete-like base now in place needs to be removed or “worked on” before adding the layers. They will suggest if drain tile is needed or other water removal ideas to put in place before adding any layers. Adding fabric would be on my list, with it under the upper layers with our clay soil “eating any kind of fill” if we don’t use fabric. But you do need thicker layers to prorect fabric from hooves, machinery that keeps the arena surface level, smooth. You may need to add some sand later, after it settles, gets moved around over time.
The dirt person you pay for their services, should be able to give you a Plan. What to clean off the space, set dirt back as you get down into the ground. The dirt may be useful someplace else on the farm if not suitable for the Plan.Then how to start building, fill layer depths, compacted depths, angles needed for draining and crowning. You CAN do it yourself, so nice having machinery! But the PLAN is like a house blueprint, showing what is needed to reach the final finished arena. Good machine drivers get that way after MANY hours in the seat of machines, moving dirt. Surveyors level might be really helpful, to keep things accurate. You can rent them now. Lasers make things lots easier to use than in “the old days.”
The dirt person is like the house Architect drawing a house, knowing stresses, electric, water and spacing for house things. Dirt folks know your area, drainage, rain expectations, how various sand and soils work, to make your Plan work for you. Ask others who designed their arena, what do they like or dislike about the finished product? How well does it drain to be back in use quickly? You don’t want to waste time or money on ideas that may not work in your location, or need to be redone in a year or two. If you can squeeze out more footage I would. You almost can’t have “too much” arena, especially if you later change disciplines. We mostly drive horses. They can gallop while hitched in there. Arena is almost 100m x 30m, before we ran out of room. I can split it into two nice size riding arenas or a BIG jump course, gallop ridden horses without being constantly bent to turn corners. I love it! Husband can drive his 4 horses together, without being cramped. We get a lot of use from it.
I would do a consult with some arena builders or footing experts before doing anything. We can only guess at your soil.
I wouldn’t do asphalt anything as it’s very inconsistent in sizing and doesn’t always compact without a tar layer.
The biggest thing is having the proper grade and density so water moves off the arena and it can dry out.
I’ll be following this with interest. Our indoor was put up in 1995, 66 x 164. A good base was put in and then apparently a mix of soil and shavings. It served well by and large. But I thought the cushion was becoming pretty ineffective a couple of years ago, so I began consulting with companies to upgrade the footing. Please note: I didn’t want it to be deep, just maybe 3 inches or so of looser material for a bit of cushion on the firm sub footing. Lowest quote I got was $15,000.
I talked to the genius heavy equipment guy with whom I’ve worked for ages. He brought me a bucket of sand/ clay mix (3/4 to 1/4) to see what I thought of it. I liked it, he installed it and I added 800 lbs of Mag Chloride. Whole thing cost under $5000. I haven’t had to water the ring at all since last spring when we did this. It’s a little dusty right now because our dew points have been so low but that’s the worst of it.
I could do the same thing outdoors, without the Mag Chloride, but I’m worried that the sand mix will just wash away in a heavy rain. I was offered some GGT (I think that’s the name). I liked it when it was damp, but when it dried, there were shiny flakes of something in the air, which I didn’t like at all. So I’m following this discussion to learn more.
I don’t have a specific budget in mind but I’m hoping to get all this done for 25k or less. I have all the machinery to do the digging, grading, spreading…so my only costs would be for material and trucking. I have a gps capable dozer so I’m not worried about the grade work or labor. But like I stated I’d like to get this right the first time so I’m not throwing money down the drain, which is why I’m on here looking for opinions. Maybe I will grab a soil sample and have it sent out so I can figure out what I’m working with. Now I’m assuming I want my sub base compacted and level, and then when I decide what to put down for my base, that is where I’ll get my grade? There’s a few people in my area that have outdoor arenas so maybe I’ll contact them to see what exactly they used for a base and if they’re happy with the decision.
Find someone who will take a few dollars to consult with you. We understand you are doing the work yourself, but what you need to know is: what is the correct work? Hire someone who knows the answer.
This is a very common footing used in my area for outdoor arenas. Typically installed over a simple clay base. Or just sand over a clay base and the layers mix some via use and dragging. Many use rail road ties are similar at the edge of arena to help keep it in place. I’ve ridden in many arenas with this construction over the years and have found them fine year round. We get a lot of precipitation. Measuring by avg inches per year, I live right between the number one and number cities in the US. That said, we get a lot of rain in relatively few rainy days. We get a lot of sun and warmth too. This kind of construction might not be as suitable for an outdoor in a colder climate or a climate that got more rainy days.
