Whether it’s monopole, I-beam, or telephone pole, every billboard begins with digging giant holes in the ground. And there are many things that can happen when you dig a hole, and many things you can hit below the earth’s surface. In this Billboard Mastery podcast we’re going to explore the lessons learned from digging hundreds of such holes.
Episode 148: Lessons Learned From Digging Holes Transcript
Whether your billboard is held up by one giant steel monopole, or steel I-beams, or old wooden telephone poles, it all begins with digging a hole in the earth. And what you know about doing that can make all the difference between it being a successful and a terrifying project. This is Frank Rolfe, the Billboard Mastery Podcast. We're gonna talk all about digging holes in the earth and what I've learned from digging hundreds of holes in the earth in all kinds of terrain. Rocky areas, swampy areas, city limits, way out in the country. So first of all, when it comes to digging a hole, you have to know that once you dig the hole, you can't undig it. So it's very, very essential, first off, that we know the positioning is correct. So take your permit, your approved permit, and get a measuring device, tape measure, whatever the case may be. Roller wheel, start at the front and say, "Okay, this sign is supposed to be this many feet from the right-of-way, which begins here." And then the pole, if it's a center mount, is in the middle of the ad face. So the center of the pole is right on this spot. And you put in a stake and then you go to the side and you say, "Okay, my side setback is this much." And then measure again where it's supposed to fit exactly down from the other sign or radius from an entrance and exit, whatever the case may be. You got to make sure you totally nail the location where that sign is to go. Because once you drill that hole and you build that thing, you can't just move it over a foot here or there. It's very, very serious business. And then when it comes to the guy who's gonna come out and dig that hole for you, you got to make sure you have a copy of the engineering and you know how big in diameter that hole is supposed to be and how far in the ground it goes. Because a lot of the guys that dig those holes cheat, and they cheat because they don't have the correct diameter drill or they just want to go to lunch and they're not gonna dig it as deep as the plans show. Once again, you got to have your tape measure with you. For this case, typically a tape measure that's nylon-based is perfect, so it's not stiff. And what you're gonna do is when the auger comes out, you can measure the auger quickly to see if it's the right diameter.
If the guy brought a 36-inch diameter auger and it's supposed to be a 48-inch diameter hole, you have to stop him right there and say, "Wait a minute here. This isn't supposed to be 36 inches. This is a 48-inch, right? You got to go get the other auger." But also, when you start digging that hole, you're gonna have to drop that tape measure down that hole and keep double-checking what that guy is doing before he stops. Because they're notorious for not going deep enough. If the plans say to go 12 feet deep, they'll stop at 10. If the plans say 15 feet, they'll stop at 12. Because they want to hurry up and get over to Long John Silver's and get the shrimp feast with the hush puppies, which I admit is tasty in some markets. But that's not gonna do you any good when they put that sign in and it's not far enough in the ground. Because here's what's gonna happen. You're gonna have the sign too tall, two or three feet too high, which if anyone catches that, they might make you lower it by that amount. But additionally, now it's not engineered to the correct wind loads. So if the big wind hits it, big tornado hits it, all the stress is on the wrong spot on that sign, on that column, and you're subject to having the entire sign fall down.
So you got to double-check the diameter and you got to double-check how deep it goes. Now, as they're digging the hole with you standing there, there's a possibility you're gonna hit some bad things. So let's go over what happens if you do. Number one, before you even start drilling a hole in America today, you need to get someone out to check to see if there's any buried utilities. Some states, they call it One Call, for example. You call up and say, "I'm building a billboard. I'm digging a hole. This is the location. I need someone to go out and mark all the utilities." And if you do that step, typically you're fine because they come out and mark, "No, you're clear, you're clear, you're clear." So you have that peace of mind. But some things you hit when you dig a billboard foundation are not on that One Call chart. One thing you can hit almost immediately is rock. If you dig that foundation and the drill bit spins and spins and goes down and suddenly it goes bang and you can't get it to go any deeper, you've hit a rock. And when you hit rock, you have two options. You can either try and continue drilling, and to do more drilling with rock, they're gonna have to go out and get a tiny, tiny little bit and drill many progressive holes into the rock till they can try and pulverize it enough to get the big thing down in there. And that can be extremely expensive. That can easily add $5,000 or $10,000 onto your sign cost.
But you need to be ready for that eventuality. You need to talk to the guy who's digging the hole. "Now, if we dig down and we hit rock, what do we do?" See what he says. The other option would be to move the pole on your sign. Now, if you're building a sign that is a center mount, you could theoretically convert it to a full flag to get around that boulder. But can you afford that? Because now your sign will be more expensive. Another option would be to actually move the physical location of the sign, but to do that, you'd have to amend the permit. So hitting rock is typically never a good thing. That's my number one fear would be digging down and hitting rock. But what if you hit the opposite? Instead of hitting a nice solid rock, you hit marshy swamp and you start just taking on tons and tons of water. In fact, when you break the surface of the earth, all you get is mud. What do you do then? Well, what you do then is you have two options based on how much mud there is. If it's muddy but not horrific, you can go ahead and continue to drill down the foundation, make sure it's the right depth, but you end up with what's called a bell hole. A bell hole looks like a bell if you looked at it under the surface of the earth, because when you pour the concrete in, it comes out in more of a triangular shape than a cylinder shape. Nothing wrong with that. In fact, some would observe that those are the strongest foundations in the entire billboard world because you have that giant bell-shaped concrete thing holding the sign, which is even harder to move in the event of a windstorm than a traditional cylinder. But if it's really almost soupy mud, almost like water, like every time they drill down, the whole thing just caves in again, then you have to do what they call casing the hole. So what they do is they bring out another piece of pipe the diameter of the driller, and as they drill down, that pipe holds the earth back. Then what happens is you put in the sign and then the concrete, and then they pull that casement out. If it all works magically properly, what you've ended up with is a traditional billboard foundation set into the muck. However, only a professional knows how to do that properly. Some areas, what they'll do is they'll put in concrete that is deliberately dry using a custom concrete mix truck, and that way the water from the surrounding muck soaks up in the concrete so that your concrete does not become too watery. But those are the main things you'll hit as you go down is you may hit boulders or you might hit a lot of water. Now, another thing you can sometimes hit in these locations are utilities that are not supposed to be there because they're really, really old. Sometimes you'll hit a water line or a sewer line, you'll think, "Wait, what the heck?" But you'll notice there's no water coming out of it and the sewer line is bone dry because those were replaced decades earlier. Those might be from the 1920s, 1930s. Now, one other item you can also hit, which you have to be prepared for, are things that are so deep in the ground they're traditionally not marked by One Call. Now, those things are water transmission lines, jet fuel transmission lines, really big stuff like that.
Now, I would talk to the city because normally when those things exist, they have notified the city and the utility providers. And sometimes you'll see signs that say, "Warning, buried underground pipeline." Well, don't be drilling on top of that before we find out what that is. So you got to make sure when you drill that you've got not only all the normal utilities, but those really, really big things figured out as well. Never build a billboard without standing there while they drill the hole. That's why I know so much about drilling holes, is I always found that to be the most terrifying moment. I don't have to be there when they assemble the sign because I can see all that, and it's hard to screw it up. But when you get underground, you can't really see what's down there. If that guy cheated on the foundation in any way, you'll never know. So being in attendance when they're drilling those holes is really vital. This is Frank Rolfe with the Billboard Mastery Podcast. Hope you enjoyed this. Talk to you again soon.