What Schools Need to Know About Running Track Construction Projects
Choosing the appropriate type of surface for your running track is critical to promote optimal performance and ensure the safety of your athletes. When beginning a track project it is important to consider timing, weather, budget, and future maintenance. Landscape Architects, Tim West, PLA, and Clay Schneckloth, PLA host this webinar episode on design, construction, and budgeting for running track projects. They will share the advantages and disadvantages of different surfacing systems, share insights on the design processes, construction scheduling, and costs of installation and maintenance. Leaving you with tips that will help you avoid issues during each step in the process and ultimately extend the life of your new track.
- Typical Track Cross Section (0:49)
- Common Track Surfacing Systems – SBR Base Mat System (1:41)
- Common Track Surfacing Systems – EPDM Base Mat System (2:35)
- Combination Track Surfacing System (3:14)
- Special Design Considerations (3:59)
- HMA (Hot Mix Asphalt) Surface (5:23)
- Running Track Design Schedule (6:29)
- Running Track Construction Schedule (7:40)
- Running Track Cost Considerations (8:17)
- Long-Term Maintenance Plan for Running Tracks (9:56)
Tim West (0:19)
So I think we’re going to start off with our breakdown of some of the track surfacing and track construction components associated with those specialty surfaces. Synthetic tracks are something that sometimes fall back into the background. It’s really difficult to keep a close eye on the track because it’s something that’s always there. It’s usually been constructed a couple of years ago at your school or in your community. So a lot of times people aren’t keeping as close of an eye on that facility as they should be.
Typical Track Cross Section (0:49)
Most of those consist of a cross-section that looks like the one that we show on the screen here. So whether you’re building a new track or you have an existing one that’s been built within, let’s say the last 15 to of 20 years, it probably looks something like. It’ll consist of, uh, about a half-inch or 13-millimeter track surfacing on a four-inch asphalt base. And that all sits on top of a granular base. That could be sand. It could be crushed rock. We want that to freely drain to an interior-rated drain tile that would go around the interior circle of the track. About 90, 95% of the tracks out there have this type of cross-section it’s a tried and true method for construction on tracks. The important part is making sure the soils and the drainage are done to the appropriate method.
Common Track Surfacing Systems – SBR (Styrene Butadiene Rubber) Base Mat System (1:41)
The most common track surfacing system is the base mat system, which consists of some sort of a rubber granual, an polyurethane full pour, which gives a consistent depth of that 13 millimeters. SBR rubber is a type of synthetic rubber, but it’s usually generated from recycled tires and turned into this crumb rubber or that product. Due to the recycled nature of that SBR is only available in black, but it’s the least costly option. It has good resiliency polyurethane and the rubber Gras bond. Well together, there is some permeability as so with these systems. So you have to make sure that the asphalt base is built correctly with no ponding so that you’re not experiencing any lamination, but we’ll get to that a little bit later in the webinar.
Common Track Surfacing Systems – EPDM (Ethylene Propylene Diene Monomer) Base Mat System (2:35)
The next step up would be a base mat system, but it would be out of an EPDM rubber. A difference on that is that EPDM is a synthetic rubber, but it’s more of a Virgin or new rubber. So you can colorize that and get almost any color that you’d like on that. The same thickness is established that 13 millimeters, but it gives you a large range of aesthetics that you can include in your project. The new aspect of the material is more expensive than recycled material, and then the colorization also costs more. So all in all the product costs a little bit more than the base mat system to add the color into it.
Combination Track Surfacing System (3:14)
We’re also starting to see some combination systems in there. The base mat with structural spray, shown on the right. You can get by with a little less SBR rubber or the base mat system at 10 millimeters and move in with a structural spray right away, instead of putting it on after the tracks have been established for a while. The advantage of this is that structural spray can hold up to traffic a little better, is more resistant to track spikes, and you can add color to it because of it being an EPDM product through the rubber spray. The disadvantage, of course, is that it costs more and there is some limit to the number of structural sprays that you can put on track. So kinda get the best of both worlds here, but you do limit yourself to the number of structural sprays in the future.
Special Design Considerations (3:59)
The special design considerations that we take into account mostly revolve around making sure the base is solid. So soil borings are an important aspect to determine the soil characteristics. We’re specifically looking for expansive soils and any types of high water table or wet soils, where it might indicate we have a water problem ’em that would potentially perch underneath our track pavements. We’re also looking to make sure that we’re draining surface flow away from the track. So if any types of hills or slopes are coming down towards a lower track, we would want to install sub-drains to pull that water away from the track and leave that pay meant high and dry. So that there’s a low chance of water infiltrating and collecting in there, and then freezing and tine over the winter months. Beyond establishing sub-drains into those conditions. We can also chemically stabilize those sub-bases if we have a tight schedule, or if we just cannot disc and dry out those subsoils by adding fly ash or a similar product, incorporating it into the subgrade. We would recommend that we carry some allowance for that anyway because even if the soils are pretty good, we would want to potentially use it. If we have an ordinary wet spring or the schedule’s extra tight, we have to have the track done and opened by a certain timeframe.
HMA (Hot Mix Asphalt) Surface (5:23)
I know you’re gonna get into discussions here a little bit later on the fly Ash, but that is a costly item. That seems to be a surprise to a lot of people when we bring that up.
Also on the HMA mix design, Tim’s been talking about the top surface portion of it, the HMA, the base that holds this top surface thing is important. Also, there are a few different things that we want to make sure we talk about here too. On the top of that HMA surface, the asphalt needs to be a smooth surface to be able to put the top coating on. So we’ve designed and worked with asphalt suppliers too, on different mixes for this top surfacing of the asphalt. We usually use a three-eights-inch rock in that mix to create that smooth surface. By doing that smooth surface there’s a possibility of some birdbaths, even with a rougher surface there’s a possibility of birdbaths. So the importance of making sure we get this at a 1% cross slope and as tight as you can without the birdbaths is very critical.
Running Track Design Schedule (6:29)
So as we’re moving into the design schedule, we’ve started the process. We’ve looked at the design of what the actual track is. Now we’re looking into, when should we start talking with you and getting this project figured out to move forward into construction. Most of our projects, we need to be starting mid-May and they happen over the summer months. Track is a spring event so we try and coordinate with the different school districts on the timing of construction. Most of this construction happens over the summer months. We back into bidding on this project and between January, February would be an ideal situation. We’d like to get this out to bid. This means we would have to back into a topo survey, getting the ground figured out what we have in that area, getting the geotech work taken care of before that. So we’re talking about October, November, December getting the survey geotech. So we can get into doing design, getting into the bid of January, February. It does take 10, 12 weeks to get the design figured out and approval. A lot of times we’ll need to go to a city for approval or school boards for approval too.
Running Track Construction Schedule (7:40)
Which leads into the construction schedule. HMA (Hot Mix Asphalt) really needs to be installed by July 15th. It does have a 20-day curing time on it before we can start putting the servicing on. Typically it takes about four to five days getting that surface weather dependent, always weather dependent, on that and getting the surface down on top of the asphalt. Nighttime temperatures need to be above 45 degrees. Once we get into mid-October, the weather is always up in the air so we wanna try and get all of that taken care of before October if possible.
Running Track Cost Considerations (8:17)
When we start talking about budget consideration, a couple of keys, we’d like to bring to your attention. There’s a lot of discussions that’ll need to occur on how the D areas are treated. That’s the infield area between the playing field and the track curvature there need to be some decisions made as to whether you’re going to continue to use that in a new format. Do you wanna do synthetic turf in the D area? Do you want to complete that with track surfacing? This includes asphalt and drains, et cetera, we’re usually encouraging people to pave those D areas, because it allows for some multipurpose space. You also can put your high jump and long jump facilities in those, within the track circle. It usually is a little bit cheaper than synthetic turf.
If you’re considering that budget numbers for a new track system, which means going from tearing out the old track and putting in new rock base, new tiles, new asphalt pavement, et cetera, is about $600,000 to $700,000.
So we’d encourage you to carry that as a rule of thumb budget number. As you start to think about new track construction, if your asphalt base is in good shape or relatively new, and you’re just is looking to replace your base mat or track surfacing system $160,000 to $170,000 will probably do it. That allows for some repair of cracking within the surfacing. And if you just need a structural spray, $90,000 is a budget, a number that we’d recommend that does include a little bit of crack repair as well.
Long-term maintenance really is important on the track. Sometimes it’s deceiving when you aren’t out there all the time. And the majority of the track is used by either the public or potentially just only by the track team. Yearly inspections are important. You can identify any sort of cracking and repair it right away so those small cracks don’t turn into large ones. We’d recommend that you walk that with a qualified contractor that specializes in those track surfacings and track repair methods. We’d recommend you also consider a structural spray in years 5 to 7. That’ll be dependent upon wear on the track and usage that will allow you to gain another 5 to 7 years over the life of that track. If you let it go all the way without a structural spray we’ve been seeing base mat wear out roughly in years 12 to 15. At that point, you may have to replace the base mat entirely. If you had a structural spray in year 5 or 7, you may I’d be able to get by with another structural spray. So when you start to consider numbers like $90,000 for a structural spray, those numbers need to be included in any projection of budgets down the road. It’s not just about the installation initially, but having a maintenance budget that you can invest into over time and hit some of these dates.