Personal Arenas - prep of the base / etc. What's really necessary?

[dqtastic]

Listen I know this is questioning common convention, but I need some education around arena base construction. Every outdoor arena here is started by digging out the topsoil (which can be 6" = 6’) then filling with big rock > little rock > crush rock > surface (hog fuel or sand mix). Lots of layers, huge investment in rock.

My big question is, do we really really need to do ALL the top soil removing and add ALL the rock? I have paddocks that are geotechnical fabric over topsoil, with rock then crush rock, and they drain well, are level and reliable with a lot of use. Could I conceivably begin an arena with geotechnical fabric, crush rock and surface (hog or sand mix)?

When i see how okay my paddocks are I can’t help but feel like I’m getting over sold on excavating and rock. Also…I’d love to find a more affordable way to do this. Thanks in advance.

UPDATED - to add - in PNW, so rain and snow in winter for sure, but I’m okay with closing access to the thing Jan / Feb.

[mmeqcenter]

It depends a lot on where you live and what your soil/subsoil etc. are, but I knew many barns in Ohio that didn’t even take out the top soil, some just dumped footing right on top of a dirt area that they grass had been killed. Some put down railroad ties and did ~4" of a compacted base on top of the topsoil, then their footing. Some just dug out 6" or so, put down a 4" compacted base, then their footing.
This would not be possible at my home in Florida with sandy soil (aka my farm’s a beach with grass).

[wsmoak]

ditto – Where are you and what is the soil like? … because “It Depends” entirely on what you’re starting with.

I was lucky enough to be starting with sandy clay and very little topsoil. I had them clear, scrape, level, and the bulldozer compacted it “enough” to then spread decomposed granite. It doesn’t drain exceptionally well, but it’s just for me, I can stay off of it when it’s too squishy. And I made sure that if I decided to go ahead with a “real” arena, they could continue from this point – putting in the arena edges and compacting a real base, and that I wouldn’t have to un-do anything I’d already paid for.

[anon55755751]

I’m also interested in answers to this question. In my area (midwest, with real winters), I know more than a few outdoors that are just sand dumped on flat ground, like mmeq said. What would be extremely useful is a breakdown like “On loamy soil, french drains+geotex+rock layers per OP+sand+reasonable care and possibly mag, arena will be usable for at least light work down to consistent (days+) of X and below temps” and the corresponding temps for lower-effort constructions…

Depending on the amount of sand and slope of the arena, sand on bare ground (and no maintenance) in this area does ok through most of Dec. (avg. highs in 30’s, lows in 20’s), but freezes solid for most of Jan/Feb (avg. lows in the teens). Same goes for the ground overall, largely. Just a heuristic from my general observations, but it does leave me wondering if I put in an arena at my place (which is the plan), and I invest in drains and/or rock and/or geotex, how many more days Dec-Mar will I get out of it? Maybe half of Jan-Feb will be a total loss due to temps/precip. no matter what? Of course a lot depends on precipitation patterns (ice this year was awful), but on average?

I know there are other considerations involved in construction decisions, but that’s the big one on my mind right now!

[TheJenners]

I never considered that, and I have lighthoof down for an all weather paddock that is rarely if ever wet…

Just shows how stuck in convention we can be sometimes… hmmmm…

[dqtastic]

@TheJenners

I never considered that, and I have lighthoof down for an all weather paddock that is rarely if ever wet…

Just shows how stuck in convention we can be sometimes… hmmmm…

That is exactly what I am thinking - is this just “The Way”? Folks in my area pull multiple feet of soil out (sandy good draining) and replace it with feet of rock - I feel like there may be some overengineering, especially for people like me who don’t have huge demands on their use (I’m happy to take a rainy week off, etc).

[TheJenners]

I’m also a fairweather rider :lol: But I also don’t want to spend the money to put one in that is unusable, and have to redo it. I plan (planned?) on starting the work on an arena this year, mostly just the excavating of an area that is already naturally level with a crown, and then adding drain rock as the funds become available, and just add it all that way piece by piece, load by load, tamping when a level is complete, until it’s an actual arena. But then I bought a sorely needed mower, so that may suck up my extra funds. Adulting is hard :lol:

But I live on clay that is non-draining. I’m surrounded by septic mounds and/or ancient traditional ones that the county has deemed non-functional or failed, so there are actually people who sell property under the table and don’t change titles because selling aboveboard would require new septics. What that all means is that if I thought I could get away with doing an arena cheaper I would, but I don’t see how I can… I can picture my footing flowing away in the winter. I’m picturing basically building a large catch basin for rain under the arena, and probably still not riding in the winter (which again, see above).

[dqtastic]

Thanks @TheJenners

Your plan sounds like a good one, I’m leaning to something like that bcs yes, adulting is hard AND expensive! I don’t envy your septic situation - that could get tricky!

[PNWjumper]

Your pastures might be okay, but are there less-than-ideal areas where the horses walk over it again and again and again? Because that’s more representative of riding in the same spot repeatedly.

I did just what you explained (minus a layer) - leveled the area (cut 4’ into one side of a pasture and raised up the other end by 4’), laid down 8" of 1 1/4" rock, then 4" of quarter inch minus (compacted), and then 2-3" of coarse washed sand on top of that.

My arena is rideable 24/7/365 and has held up through the last 15 years of decent use (4-8 horses a day) beautifully. I’ve added more sand twice, but haven’t had to do any other fixes or changes.

In our weather, I wouldn’t plan to do less. I have many friends with indoors who built “fair weather” outdoors and skimped and now have arenas that are only rideable for about half of the year. It’s not about “taking the day it rains off,” it’s having an arena that holds water for weeks after heavy rains. Drainage is so so important around here!

[dqtastic]

@PNWjumper

I did just what you explained (minus a layer) - leveled the area (cut 4’ into one side of a pasture and raised up the other end by 4’), laid down 8" of 1 1/4" rock, then 4" of quarter inch minus (compacted), and then 2-3" of coarse washed sand on top of that.

You’re near me - so this is super thank you! ONE question for you which will help me figure this out - when you raised up the 4’ side, what material did you use? I have a similar spot…will likely copy what you’ve done - really appreciate you popping in!

[PNWjumper]

@dqtastic

You’re near me - so this is super thank you! ONE question for you which will help me figure this out - when you raised up the 4’ side, what material did you use? I have a similar spot…will likely copy what you’ve done - really appreciate you popping in!

We used the 4’ we cut from one half to fill the other half. So I guess the answer is “fill dirt.”

[dqtastic]

@PNWjumper

We used the 4’ we cut from one half to fill the other half. So I guess the answer is “fill dirt.”

Ooooh this is exactly what i was hoping. Thank you so much - you’ve given me some optimism!

[callyhan]

Usually the topsoil is removed because it contains organic matter that as it decomposes will cause uneven settlement. However, if there is no organic matter in the soil, you wouldn’t have that problem. If it’s a grass area it would be wise to at least strip the sod.

The different levels of aggregate is again to prevent against settlement and to assist in drainage. The bigger the rocks, the bigger the spaces between rocks, and the more space for water to drain. In freeze/thaw weather, it leaves room for water to expand when it turns to ice, therefore not heaving the ground. Clay soils are very prone to heaving as the soil particles are so fine.

It really depends on the soil type where you live, sandy well draining soil that requires a lot of irrigation to support agricultural activities would be far better than clay.

[dqtastic]

Thank you so much @callyhan ! That helps me understand the difference between top soil / sod / lower soil type. We don’t have any clay here, just multiple feet of good draining sandy stuff - but I see people removing 6 feet of it to replace with 6 feet of rock - makes sense to me that you need the rocks for drainage / expansion as you explain, but I don’t get that much water (and if i do, i don’t need to ride!) . The amount of rock i’d need to truck in for 4 - 6 feet replacement kills my entire budget and then some, so I am feeling more optimistic now that I don’t need to remove multiple feet of material that already drains quite efficiently.

Super helpful - thank you

[PNWjumper]

@dqtastic

but I don’t get that much water (and if i do, i don’t need to ride!) .

If you live near me then yes, you do get “that” much water, and it’s not about “do I want to ride while it’s raining?” (that’s often an easy pass), but “do I want to ride for the 4-5-10 days after the week or two of nonstop rain?”

The problem around here is that the rain is so constant that the ground never gets a chance to “catch up.” So if you don’t put in decent drainage (i.e. all that rock you’re talking about), you wind up with a swamp from Nov - June. I’m not saying you need “several feet” of rock, but I think the most crucial part of my arena is the 8" of 1 1/4" rock.

[GoodTimes]

I’m going to add in another “it depends”.

How much will it get used? What kind of use? How big? Is it in a spot that will get sun or a breeze?

At my parents previous farm the ring was about 80’ x 110’. I was still at home when it was built, so at most it was ridden in 6 days per week by two horses. Flatting and a small course of jumps. When I moved out and took my horse with me it went down to 3 days per week of my mom riding her horse (shorter, fair weather rides and smaller jumps).

The soil there was mostly clay. Instead of paying for crazy amounts of rock we used regular fill to build up one end of the ring. Put a few inches of gravel down, compacted, and then added sand. The top 3/4 of the ring was always usable, the bottom 1/4 would take an extra day to dry which I never found to be a big deal, but if the ring had of been smaller to start with it may have become an issue. It looked the same 15 years later, sadly the people that bought the property don’t have horses. In a few years the grass will just take over.

My mom is in the process of designing the ring at their new place. It will just be her riding a few days a week. The soil is similar to the previous place. Her plan is to build into the side/bottom of a fairly steep hill, with a pond on the other side. To prevent wash outs she’ll have to add in a bit more gravel. She’s also planning on planting cedars all around instead of fencing it - putting posts in clay is a huge PITA.

The more perfect you want your ring, the more work you need to put into the base. Decide now it you want a show worthy ring, or just an area to ride that drains reasonably well.

[Spyder]

Haven’t read all suggestions but beware of putting geo-textile fabric down for the arena. Unless it is placed at a depth beyond where a groomer reaches, the groomer can snag the textile fabric and you can imagine the consequences.

[TheHorseMutterer]

At the risk of thread hijacking…

On clay soil, what’s the verdict on whether the larger rock is more or less necessary?

I have a hastily-made dry lot on a clay base that’s 4-6" of M10 that has done well for the past year with heavy use. The riding area I’m envisioning is going to be light use (1-2 horses every couple days). Leveled properly, will the clay shed the water the way I’m thinking versus needing the additional larger gravel/stone to wash through? I keep second guessing my thought process on this and can’t figure it out.

I’ve read Underfoot and while I agree with just about everything, I can’t swing that kind of budget in the foreseeable future. A well-draining spot with decent footing is what’s going to work best for me.

[Libby2563]

Can’t speak to the PNW but FWIW to anybody, I’m on “Penn silt loam” and to build my arena, the contractor stripped the topsoil, graded, and added 6" of compacted stone dust. No larger stone or geotextile fabric. It has a 2% crown. It was built on a hill so the fill from the high side was used to build up the low side. There are swales on the high sides for drainage. No dirt had to be trucked in or out.

All of the other contractors who gave estimates said the same thing, except for one who recommended 8" of stonedust and one who told me that topsoil can be feet deep in my area so he wouldn’t know how far down he’d have to go until he started work.

I’m 100% happy with the contractor I chose and with my arena. It has been exceptionally wet here since last July and I typically only miss a day of riding here and there when the footing is so saturated I won’t risk it. In January I took a week off due to snow, frozen ground, and the aftermath of the snowmelt. I find that dragging the arena before it rains or snows decreases dry time a lot because the water doesn’t puddle in the hoofprints. I did have a horse take a few chunks out of the base during a moment of exuberance while longeing a few weeks ago and I won’t longe when it’s been that wet anymore. The builder has always told me I can ride no matter how wet the arena is, but I prefer to err on the safe side. Hopefully this quantity of rain isn’t the new normal.