IFAI’s staking and ballasting studies have helped to push the tent rental industry forward in terms of safety and professionalism. Here’s how tent rental companies can use the studies to set their business apart, plus anchoring tips from the experts.
The IFAI Staking Study and the TRD (Tent Rental Division) Ballasting Tool have improved the real-world practices of tent rental companies, says Jim Reyen, business director for Eureka! The Tent Co., Binghamton, N.Y., and TRD chair during the development of the ballasting tool. “They’ve forced our industry to do things better,” he says, “but there is a lot more room for improvement.”
The staking study, the ballasting tool and the IFAI Procedural Handbook are three TRD-developed resources that have raised industries standards and safety. (See the sidebar on page 37.) Here, three experts—Reyen; Michael Tharpe, TRD vice chairman and national sales manager, Rainier Industries, Tukwila, Wash.; and Nick Deninno, owner, PTG Event Services, Bethpage, N.Y.—answer questions from InTents about how to use the studies to get better at anchoring tents. Tharpe and Reyen lead training sessions and contributed to the development of the ballasting study and the most recent edition of the handbook. Deninno led an educational session on staking and ballasting at Tent Expo 2019 and serves on the TRD education committee.
Using the studies
How can tent rental professionals apply the information in the staking and ballasting studies within their own company?
Reyen: The goal of the staking study was to come up with a user-friendly way to test soil to give you the approximate holding power of stakes in the field. You could bring in an engineer to do soil testing or use a dynamometer, but those are not user-friendly or cost-effective ways to do it. You want to test the soil in advance, so you know how to prepare for an upcoming job or how to quote it. And the day of the event, you want to retest it because things change—the soil becomes drier or damper—and the holding power might not be the same.
The way that a person can improve their knowledge of how to stake correctly is to use the staking study test, because you will find out pretty quickly that different soil conditions and types of soil change the number of stakes you need. The angle of the stake and the size of the stake changes the holding power. The way the stake is attached and the attachment point from the tent to the anchor matter. There are a lot of variables that go into it, but very quickly you learn what matters and what doesn’t. With a sledgehammer, a tape measure and a stake, you can quickly get a good estimation of the holding power of that soil.
Tharpe: For ballasting, employees should be trained in understanding how ballasting can be accomplished and the factors to consider to properly ballast a tent. Ballast can be accomplished in several ways: Weight can be positioned on top of a plate that is attached to the base plate of a tent. Weight can be distributed via a web and ratchet or rope to the eaves of the tent. Weight can be attached to both the baseplate and attached via a web and ratchet or a rope to the eaves of the tent. Finally, weight can be positioned on top of a plate that is attached to the eaves of the tent via a web and ratchet or rope.
The factors to consider are the type of tent and configuration required; ground type or surface condition; required load for the tent; and type and geometry of ballast to be used. These are important factors for using a proper ballasting system to assure that tents are installed correctly.
Deninno: Eliminate the guess work in ballasting. People do a lot of guessing, and say, “This is what I’ve done in the past.” Know what your tent needs. Get the information from the manufacturer and actually look at the numbers in the ballasting study. Make a cheat sheet so when your sales people book a tent that has to be ballasted, they know what that tent needs.
How can the studies be used to educate local code officials and customers?
Tharpe: Building a relationship with your code official should be a priority. They, in most instances, do not know what they are looking at when reviewing a tent on site. Therefore, you must do everything in the proper sequence to train your code official. Show the code official examples of bad staking techniques and what is not acceptable for safe tent installations.
Reyen: If you want to elevate the entire industry, and especially your individual company and skills, you have to be able to explain the “why” to the customer. If you go out to a site and use the staking study and identify that the site requires twice as many stakes as, say, another site that has different soil, you have to explain, “I’ve come in with a professional tool to test the soil to make sure we use the appropriate amount of stakes so that this event goes off without a hitch and no one gets hurt.” If you can articulate it to the customer so that they don’t think you are just overcharging without any kind of reason, you can differentiate your company in terms of being more professional and that your price might be a little more because you are doing it right versus taking short cuts.
Deninno: Where the ballasting study comes in handy is showing it to a customer. For example, in the middle of bidding a job, a customer says, “Well you know, I have another quote, and it’s a thousand less using water barrels or sand bags.” We can say, “Here’s why we are using this much weight. Here’s why we are charging what we are charging, and here is some back up to show you what we are doing and why we are doing it.” That’s very helpful in securing jobs and confidence. Securing the confidence of the customer is a big win, because they understand that we have safety in mind and we are looking out for their best interests and their guests’ best interests. They will always appreciate that and come back to you again. That builds a good relationship.
What information do you need to use the TRD Ballasting Tool?
Tharpe: There are a couple of important pieces to this puzzle. The size of the ballast being used (length/width/height) along with the manufacturer’s installation instructions and/or engineering documents that reflect the loads that are placed on the tent. Consult your manufacturer if you have questions regarding the loading factors that are placed on the tents that you own. This clears any confusion as to the loading factors required with the ballasting tool. Maintain a chart of the different ballasts you use so that you can place the correct dimensions to get accurate, recommended ballasting information.
Reyen: The ballast study is a conversion tool, taking the amount of holding power that the manufacturer has determined is required in a staking application and converting it into weight. There are a lot of variables—surface modifiers, different types of ballast. . . . The manufacturer won’t be able to tell you how much ballast to use, but they should be able to tell you the required holding power to meet for whatever specific wind rating you are looking for.
What are the common mistakes that cause tent stakes to fail?
Tharpe: Stakes fail when they can no longer resist the tension/frictional forces holding the stake into the ground. Soil type, soil density and the moisture content of the soil greatly affect the stability of the stake. The end results in the sideway force that is greater than what the soil can hold back. This causes the soil to bulge, and then the stake loses its frictional hold. There are several factors that can affect the soil’s resistance to failure:
- The deeper the stake is driven into the ground, the better the holding power and the greater the soil wedge that resists the stake from moving.
- Attachment point: the lower the attachment point of the guy, the greater the holding power.
- The larger the stake diameter, the greater the holding power. This creates a much larger and tighter compacted soil zone.
- Stakes driven straight into the ground provide greater holding power and create a larger soil wedge for greater resistance to the soil for moving.
- The angle of pull can affect holding power. Pulling too close to the side pole will cause the stakes to be easily lifted out of the ground, while the angle of pull too far will cause the side poles to be lifted off the ground. Once the stability of either of these items are lost, you are on your way to failure.
Reyen: People assume that angling the stake farther away from the tent gives it holding power. That’s a very common mistake. When you stake you are creating a soil wedge. You want the triangle that makes up the soil wedge to be as large as possible. When you have a stake that’s very angled, you are reducing the size of that soil wedge, so it will be easier to pull it out. You want to have the optimal soil wedge, which gives it holding power.
What is your best tip for staking?
Reyen: Do a site survey and identify what you are up against soil wise. You want to have enough stakes for that day on the job, and you want to bring extra in case conditions change. And use the study—it’s very easy, and you can tell pretty quickly if you are going to need additional stakes.
Deninno: Call 811. It’s a pretty clear law in all 50 states. I hear, “Well, you could let the customer do it.” No, you really can’t. You are the contractor—you are the one doing the work; you are responsible, not the homeowner. You can have them sign off all you want, but if you hit a gas line, forget about codes and fines—you are putting your staff at risk.
What are the common mistakes that cause a ballasted tent to fail?
Tharpe: Ballasting failures normally occur when the ballast slides on the ground on which it sets or on the plates on which it sets. These failures also occur when there is insufficient ballast being used, which causes the plate of ballast to be pulled or lifted off the ground. This reduces the effect of resisting the forces placed on the tent or temporary shelter.
Reyen: A lot of people don’t look at all the details of the ballast, such as the attachment point and the structural integrity of the attachment point. A water barrel may be 500 pounds, but you can’t connect a rope or a web and ratchet to an attachment point that is only rated for 50 pounds.
Weight is weight for vertical lift, even for water barrels. But in a horizontal load situation, different ballasts perform differently because concrete coefficient of friction is very different from plastic.
Deninno: The number one thing is underweighting. Number two would be having the ballast out too far from the tent. Whether it’s a water barrel or a block, the physics are the same. The farther you are from the tent, pulling at an angle, the more leverage you have to pull the block over. When ballasting, it is in your best interest to have the block closer to the leg.
Attached to the leg is an even better scenario. Tipping the barrel or block over is eliminated because it’s tied to the leg. Plus, it holds the leg from moving, which is usually what compromises the tent. If you set up a tent and a block and you put, say, a 500-pound block six feet from the pole because that’s where you’d put your stake lines, the block is much easier to tip because of the tension and the angle. Once you elevate it just slightly it could slide in closer. And once it slides in closer, you’ve compromised your tension. The tent will start to oscillate or bounce up and down, putting undue stress on the strap, which now will cause the block to move even more, causing more bouncing. That’s when something fails.
It’s always better to have the ballast close to the tent. Sometimes this means having two ballasts, so one is very close to the tent against the leg and the other is right next to the first block, where you have your guy strap coming down so you have a good triangle going back to the tent.
The other common mistake in ballasting, unfortunately, is with water barrels. Besides the plastic factor, they rarely get filled all the way. If you have a 480-pound water barrel, but you only filled it three-quarters of the way, you don’t have 480 pounds.
What is your best tip for ballasting?
Tharpe: Always ballast to the worst-case scenario.
It is best to have too much ballast than having too little ballast. You should never underestimate the power of Mother Nature. There are several key findings as well to think about when using ballasting:
- When using a plate, secure the ballast to the plate.
- Weight positioned closer to the tents, while maintaining manufacturer’s requirements, optimizes performance.
- Higher density ballasts are optimal.
- Modifiers (rubber pads, plywood, etc.) reduce failure due to sliding.
- Staking is a much more cost-efficient way to secure at tent.
- Steel barrels are much better than plastic in terms of ballasting weight.
- Concrete blocks are better than steel barrels terms of ballasting weight.
- Concrete fill is a better source of ballast that water-filled ballast.
- Ballast can be offset, without any change in the required ballast weight, by up to half the width of the ballast, for entrances and other obstructions.
Deninno: Have a good means of transporting the block. A cheap ballast doesn’t make it efficient, because if you can’t move it, you will have issues. I’ve seen a lot of people take a 2,000-pound ballast and use a forklift to move it. They will put it down next to the tent, but they will put two strips of wood down so they can get their forks out. Now the block is sitting on two pieces of wood and can slide right off because there is less resistance. They are losing all the friction of the block on the ground. Picking up a block from the top and having it go straight down on the ground or a flat full-width rubber mat or plywood will give you the best friction for keeping it from moving. Always have as much surface area as possible touching the ground or rubber between it touching the ground so you have more resistance.
IFAI Staking Study
The IFAI Staking Study produced a user-friendly method to test the holding power of stakes to meet the manufacturer’s required anchoring loads. With this simple test, installers, sales people and code officials have access to the same information. The test is described in the “Pocket Guide—Pullout Capacity of Tent Stakes,” first published in 2006.
TRD Ballasting Tool
The Ballasting Tool is an online calculator that resulted from a study completed by TRD with the Clemson University Department of Engineering, Clemson, S.C. The tool helps tent rental companies determine the best methodology for using ballast units to anchor frame tents and clearspan structures and determine the expected mean coefficient of friction for different common types of ballast on a variety of surfaces.
IFAI Procedural Handbook for the Safe Installation and Maintenance of Tents and Fabric Structures
The Procedural Handbook is a living document of information on how to execute safe and quality tent installations. The document includes information on site survey, layout and anchoring (including the staking study data summary), poles, tensioning, sidewalls, and safety and maintenance for a variety of tent styles. The handbook was significantly revised in 2017.
TRD members may download the Pocket Guide and the Procedural Handbook and access the ballasting tool at the “Resources” dropdown menu on the TRD website, www.ifai.com/tent.