Culvert curation–everything you need to know with field expert and HDPE veteran, Don McGriff. The benefits of slip-lining with Snap-Tite and Spirolite to rehabilitate failing culverts – detailing the low-impact, long-term solution that improves on the original.

Sean Moth 

Welcome back to ISCO insights podcast, our newest episode is going to focus on covert rehabilitation. And we are thrilled to bring in our local expert Don McGriff. On thank you so much for your time. We really appreciate it. Yeah,

Don McGriff 

enjoy you being here.

Sean Moth 

Tell me, just give me some background on you. We talked a little bit about your initial aspirations to head into space, but you derive those plans a little bit, but maybe some of your experience in the HDP. Yeah, so

Don McGriff 

I finished college. Actually, before I was finishing college, I started in little polyethylene company called fluid controls, which eventually was acquired by ISCO, in 99. But so essentially, I’ve worked out of the same location since finishing college. So I’ve done ACP for over 30 years, done a number of different technical aspects in in supporting polyethylene, and its uses in his installation and fabrication, from the industrial municipal to landfill, geothermal nuclear covert rehab, which I’ve supported for a number of years, and then had the opportunity last year to kind of start in sales. So, so a bit involved with a number of things there and dealing with trade organizations associated with that, whether it be STM, or E SME, or ESC or ash toe, just, you know, so technically, kind of cut my teeth there. And then when I figured out how to, you know, talk to people, I wanted to be in sales, at some point actually. Spent

Sean Moth 

fantastic, obviously very seasoned. I’m just the opposite new to the industry been around here at a ISCO for about nine months. But I think I talk to people about it, and I say culverts, why are we talking about culverts? And as I’ve done the research, federal and state funding is headed that way. And there are a lot of problems with culverts, whether it’s the timing or the shelf life of the installs that were put in, but there’s a lot of failing culverts around the country and around the nation.

Don McGriff 

Yeah, there’s a lot of infrastructure dollars out there. And most of us go into things that are seen, so you’re seeing a lot of roadways that are being repaved. Unfortunately, you know, the maintenance crews for whether it be a DLT or county city what not, you know, they’re they’re still strapped a little bit. They’re, they’re trying to find funds that some you know, are proactive about their culverts, some are just waiting till they can have more time or have more money or have more manpower, number of different reasons. While they may not want to go look what they know is his problem. Kind of a ticking time bomb, you know, there’s probably a little bit more attention to bridges, because bridges fail, it’s a little bit more catastrophic than, say a culvert but of course is going to do a fair amount of damage as well. It’s

Sean Moth 

something I’ve kind of stumbled across too is sometimes it is they know about it, and they just want to put it off sometimes it’s they’re maybe not really aware of how poorly the culvert is doing or how it’s failing.

Don McGriff 

There’s all sorts of situations depending upon like I said, I think many know, but if they if they don’t feel like they’re gonna have the funding that might go look, sure,

Sean Moth 

sure. So just for a simple definition. I think people that even think they don’t know what a culvert is know what a culvert is, give me a rough definition.

Don McGriff 

Yeah, you can think of it as a pipe on a road. But really, it’s a it’s a conduit, you know, allows typically water stormwater, water runoff go from from one side of a road or railroad or a road, airport runway. There’s there’s culverts and levees and dams. So it’s just a matter of channeling, typically rainwater or stormwater that’s come from some direction. And it’s got to go eventually back to some sort of body waters train lake or something like that. And our roads create, essentially small dams for that so

Sean Moth 

and your point about the storm water and the rainwater being the source kind of puts an exclamation point and maybe the awareness of when they need to be addressed because sometimes it’s not until that surge that water really comes in you realize, okay, we got some deterioration we’ve got a clog we’ve got other problems with it. Yeah, not always active. Yeah, sometimes

Don McGriff 

you know, the culverts are dry they’re only active you know, after a rain and then you know, once the rains been dries, but some of them are part of it oh stream bed. So it’s just a matter of, you know, where the where the water is coming from groundwater, rainwater, some other source.

Sean Moth 

I wouldn’t put a percentage on it, but I think just from eyes, corrugated metal and cement kind of concrete are basically the primary in copper. Oh, yeah,

Don McGriff 

of those two materials. Definitely. You’ve got some older stuffs and some claims and brick, you’ll typically find that in the Northeast where the infrastructure is substantially older than the southeast, the West whatnot but corrugated metal was was very popular in the 50s 60s and 70s. And so those were hitting those design life. They weren’t protected. They weren’t galvanized or epoxy coated like they are now. out. So you’ve got a lot of unshielded metal. And then the concrete does fairly well, in some situations that the aggressive souls are aggressive. Going back to rainwater, we used to talk about acid rain, things like that. There’s some, there’s some concrete colors that are spotted and things like that. But between those two, you’re gonna find most of them, you’ll see, within the last 20 or 30 years, this switch over to a corrugated plastic corrugated HDPE, not quite the same thing that we’ll talk about in a minute, but because it’s a little bit more corrosion resistant, abrasion resistant?

Sean Moth 

Sure. Has there been an impact on culverts and their failures because of population growth and heavier traffic on some of these roads? And maybe the consideration not being put in during the install years and years ago?

Don McGriff 

Potentially, yeah, there’s, you know, as you create more subdivisions, things like that, you’re going to increase the groundwater, you increase the runoff. So you’re going to you’re going to crease load. Now that may be good or bad, depending upon the situation. Sure.

Sean Moth 

Some of the considerations, then when you’re talking about a culvert, trying to decide if it’s, it’s a rehab, if it’s a repair, if it’s a replacement, obviously, the size, the length, the depth is probably going to be the primary, what are some other considerations? Oh, there’s

Don McGriff 

lots of them, you know, the weather, there’s utilities involved, the amount of traffic that may be involved in a roadway. Sometimes the roadway is not got a lot of traffic, but it’s the only way into a subdivision. Therefore, there may be a lot of traffic, you think about a road that goes into a state park, it’s typically one way in one way out. So, you know, there may not be a lot of cars, but that’s the only way they’re gonna go. So that becomes the so detours become a headache, you can talk about environmental concerns, you know, and that’s become a big one. Oh, yeah. The, the sustainability, the the environmental impact. The lots of terms out there that catch people’s attention. Sure. Sustainability. But, you know, there’s, there’s the hydraulics that matter. Yeah, you get a failing culvert, or you get water, it’s bypassing it, you know, when you decided to repair to place, you know, we’re gonna go back with the same amount, you know, like I said, it was put in 30 years ago, and then we didn’t figure we’d have 10 subdivisions feeding that I wouldn’t call it. So they get a little undersized. And in some cases, you know, there’s the, the structural capacity, you know, it was a two lane road. Now, it’s a four lane highway. You know, typically, that shouldn’t be a concern, but sometimes it can be, and then you just get the design life and the cost of pick it up. Should I replace it? Should we have

Sean Moth 

it good old time and money? Always coming in? Yeah, no question about it. So when we look at solutions, obviously, if if a replacement is one necessary or two possible, logistically speaking, I would guess that is the best solution from a duration standpoint, but it’s really challenging in terms of, again, is involved,

Don McGriff 

again, depends on those conditions. So if the culverts collapse, it’s probably a good time to replace it, there’s not much you can do with it with a rehab or rely method. If it’s low volume, low traffic, it’s convenient for a DLT roadway to go by, you know, to go and dig it up within a half day because that’s what they do every day. The deeper gets, the more challenging, you know, you’re talking about shoring and, and right aways and things like that, that makes things more complex. Again, we talked about increasing capacity, you go from small cover to a big cover or small coat to a bridge, you know, sometimes those are justified and needed. So there’s a number of reasons to to replace, that might make sense. But typically, what you’re talking about, with with repair replace, is there some sort of economic advantage, maybe not immediately aware to people, but there’s an advantage to doing that. Sure.

Sean Moth 

So spot repairs, close fit liners and slip lining are kind of the triumvirate of of rehabilitation means or is that accurate? It just in general.

Don McGriff 

That’s just kind of three three buckets. We’ve kind of talked about, you know, a spot repair. typically something that doesn’t address the entire culvert Sure. There’s two or three things there you know, the joints separated you just put in a new pipe but some reason wasn’t backfield correctly. The joints kind of separate. You might could do a simple joint sleeve, something that’s non structural, but you know, keeps the water out keeps water flowing through across groundwater out keeps water flowing through it. Yeah. You know, there’s grouts that may stabilize the soil or prevent a crack from further human, you know, getting water in or or developing, paved, inverts or common spot repair paved inverts or something where the bottom is kind of rusted the rest of it’s fine but you know where the water sits, maybe probably doesn’t move very fast and capture comes in and sits get a lot of deer deterioration so paved in may give some life and at a cost or you know, conveniently something that somebody can do because they can get in and they can lay a new bottom to

Sean Moth 

Yeah, close fit liners we’re talking about basically, whether it’d be the fabric or the infused materials or some sort of spray on your you’re putting a new liner in the culvert is it in general, I guess it’s we’re talking about I think there’s probably, I guess, three primary close bid liners, yeah, the

Don McGriff 

we call them close fit liners because it’s a designation the Corps of Engineers likes to use, okay, they consider close fit line or something that’s going to basically move up against or be installed up against the existing wall, the host. And it’s something that’s going to be it’s attractive hydraulically, because it is reducing the idea, the minimal amount, you’re talking about something that that is pulled in, but again, expanded up against the existing host. So you’re talking about cured in place is one a folder form is another in an S spray pod pipeline, or a sap L is the typically three that fit in that bucket.

Sean Moth 

Now, I know with with slip lining with HDPE, you’re looking at the opportunity to have that smooth wall interior improve the improve the flow rate, with these three opportunities, are you replicating that corrugated metal then with the replacement, or is there maybe a chance to improve the flow a little bit,

Don McGriff 

typically, there’s, there’s likely a flow improvement. One, because when you’re putting these flows, fit liners, they don’t always fit exactly into the hills and valleys, let’s say of a corrugated metal. So they’re going to, you may still see some sort of undulation, but not to the same extreme. With a spray applied in, they typically kind of spray it until it gets smoother on the exterior and outs. It’s a switches. So it does have some roughness to it that, say a folding form, which is a PVC pipe, you know, it’s going to be very smooth from a from a thermoplastic standpoint. But it is going to have a little bit of undulation than say a standard PVC pipe that you might see in a home improvement store. The curative place again, is it’s going to follow that contour a little bit, but even adapt a little bit.

Sean Moth 

And I think we make this clear on the podcast and other insights that, you know, we’re here as a function of informing and all of the solutions we speak to could be perfect for your situation based on all of the circumstances obviously, the one that we have a vested interest in is one we’re going to talk about a little more. But you know, one of these might be the perfect answer to your questions. And so we we don’t want to speak, you know, in terms of negatives, and we’re not, we’re not trying to sell against these, we’re just trying to inform your positives and negatives. And I know that the

Don McGriff 

trade offs, like with a close fit liner system is it works well in a closed system, things that don’t have a lot of access. So you think about something that goes from a manhole to manhole, catch basin, the catch basin, you know, most time we’re talking about culverts, and they’re open ended. And sometimes we’re talking about storm drainage pipes that are along the side of the roadway. And so you never see the entrance and exit to some of these concrete boxes that may exist. And so when that flexible liner can make a 90 degree turn pretty quickly, versus versus a hard pipe, like the foot ladders that needs a little bit more room, anywhere from 10 to 30 feet that we may be dealing with with our foot ladders. Yeah, it’s good to have a number of tools in the toolbox that fit based upon the you know, where you can accept the trade off.

Sean Moth 

But with all of those clothes fit, you’re not going to address any of the structural integrity of the of the pipe and, and surrounding areas so to speak.

Don McGriff 

It’s it’s a it’s a conundrum within the industry. Sure. You know, there’s some aspects where they call them non structural up to structural the AW wa gets involved because some of these methods started out with the water and sewer rehabilitation methods with smaller diameter pipe, smaller bores, smoother bores, and it’s been adapted over time for for culvert. And so they fit and don’t fit in the same categories. Sometimes, you know, people think I got a pretty good host, I’m going to do this as a as a new line, a new seal a new line or a new you know, something’s vent corrosion. And if the the existing culvert is not that far gone, it may not be a terrible idea. One of the things that we contend is sometimes these corrosions are too far gone and you put one of these methods in and basically holds the ground water in and basically exacerbates the corrosion. So you kind of have to decide I’ve seen some references where some play say that, you know, a CI PP is a good reinforcing material, but it’s not really considered structural. I’ve seen an article last month and underground infrastructure we were talking about just the lack of guidelines for design and install. And just a number of factors that say SAP PL shouldn’t be considered structural at this point. There are factors that go into the design of, you know, they start with, you know, swimming around, and most of the failing infrastructure is not around anymore. It’s, it’s elliptical, it’s got some sort of deflection and those deflections are where things can create some issues. Sure, groundwater can create some issues, freeze thaw, especially when more than environments create a lot of issues. So, so you get these, we like to tell people, like, don’t just take the word for a vendor. You know, we’ve got a design methodology, check us out to see if we’ve missed something. And same way for these other methods. Again, everything fits. It just needs to make sure that, you know, does it fit in the way that you think it should? And

Sean Moth 

I know that if there’s particularly environmentally sensitive setting that you’re attempting to work on this culvert to that there are and have been some documented chemical concerns with some of these other manners of repair. Yeah,

Don McGriff 

so the CIP has a stiring component you know, they’re typically ester resins vinyl ester polyester, some epoxies. And so when they’re cured as a form of you know, making them from a pliable into a cured hardened thermostat form, starlings are given off now, I think most of this only non covert is probably more pervasive it, you know, sure, you’re dealing with small pipes, so they use a lot of steam and, and hot water. And those are where the stars are a little bit more uncontrolled. When you get into culverts, you know, something that’s a little bit larger than maybe a sewer waterforce Main, they’re probably going to use a lot of UV and UV tends to, it doesn’t really let starlings out, the issue is you’ve got to make sure it’s fully cured. Otherwise, they will still leech out what’s the waters there. So so the UV makes a lot of sense from the the culvert rehab situation. But it’s just not a slam dunk.

Sean Moth 

I know that whatever the timeline is, 1015 years ago, the definition of large pipe was very different when it came to high density polyethylene. That has expanded exponentially I guess we’re up to 120. And or even bigger in terms of the the diameter. That is one of the restrictions with some of these, these close bit liners is that they’re only going up to a certain diameter at this point in time. Well, they’re expanding to I’m sure, well,

Don McGriff 

actually depends on the methods, okay, so with a sap, where you’re talking about something where you’ve got to spray a lot, or some inches, you know, there’s a bottom end for it, sure, they can go pretty big, the bigger it is, the more room they have for spraying the by hand by doing a spin, Rotary spin, things of that nature. But yeah, the fold and forms typically a 36 inch, I’ve heard talk about 42 and 48. But it’s just not it’s not as common in the industry or just hasn’t hit yet, but, you know, there’s that the CIP goes from a low to too large, but a lot of what I see as CIP has its sweet spot for 48 inches down the cost the headaches, the logistics, so to speak, all kind of affected as being more more economically justifiable as as as a low end to 48 inch size,

Sean Moth 

you touched on a little bit without saying it, but as we transition into slip lining, the one requirement you do have is a bit of a staging area in order to accommodate that but but in general, slip lining allows you to address not only the flow rate not only the failure of the cover, but also some of the structural integrity with the grouting and and the bulkheads as well. Yeah,

Don McGriff 

primarily, the advantages structural, you know, people are comfortable with a pipe that’s normally sold as a pipe right? Yeah, so now it’s just putting a pipe inside of the pipe, it’s just making sure the hole is big enough for the pipe slide through. So and the advantage of of a salon or lease with the snap title as far as like products that we talked about, is that those things are extendable Onii Chan, so you know when people are running short on shoulder or they want to go from a two lane road to a three lane or four lane, you know, they can line the host and leave the extra on the ends for however they need it, whether it be three feet or 30 feet. So you know they can direct bury that portion and line the other and so when they’re done looking through that pipe, it’s all continuous. So the structural is is an aspect of the salt line and that makes sense to a lot of people and I’m

Sean Moth  

understanding that the steel and then some reinforced plastics, PVC but primarily HDPE are used in slip winding

Don McGriff 

there are still a number of materials out there, the steel reinforced, really is a good for a direct, very type pipe. Because it’s got the ridges on the outside, it’s a little bit more cumbersome to get it installed. reversals like smooth exterior smooth interior pipe that we’re offering. But you know, every tool for the tool bag, but yeah, some of the other materials PVCs use. And while configuration can be a little finicky on durability, you got to be a little bit more careful with it. That’s my best contractor say I love your product, because I can beat the crap out of it. Yeah, yeah, I’ll have to modify the language. But yeah, they, they, they drop it, they roll it, they, you know, they do some things that we don’t recommend, and it’s still survived. But yeah, so the polyethylene, the thing about it is it’s, it’s, it’s becoming universally accepted across a number of different markets. And in this, it offers some, some structural, some flexibility, some, some just robust characteristics. But typically, you know, in a financial or economic range that makes a lot of sense.

Sean Moth 

solid wall, ASTM F 714, either mechanical joints that snap tight, or butt fused, I almost feel bad when I refer to snap tight as grown up Legos. But to an extent, I mean, as far as assembly goes, while it is much more complex than that. Now, that is a simple process, you get the gasket on there, you get a little spray on there, and you snap it in. Yeah,

Don McGriff 

so the pipe normally is a heat fuse pipe for a lot of the applications because the heat fusion gives you a pressure component, we needed to make that a little bit more simplistic, especially for the in markets that we’re using, we don’t need the press capability, you know, so we lose that when we machine the male and female land. But we take something where you know, you have this specific piece of equipment that might be required some specific expertise. And again, some sort of logistics to be able to put the pipe and keep things clean and dry, make a heat fusion, take all that away by making a male female and, and therefore, the snap goes very quickly. I mean, minutes, if you know, depending upon just how well someone’s set up how comfortable they are with doing it, you know, they struggle with the first one because they haven’t seen it or only seen it on picture video. But once they get going, it’s quick. And so we take that aspect out of it, you know, making it something where all they need is a little bit room on the right away, they’re gonna stick one join in, have enough sticking out nothing to hold on to keep it restrained, and pull the next joint in. And it’s left, right up and down, just trying to get your alignment and and then it snaps instantly.

Sean Moth 

When you when you when you talk about it. I guess if we were writing rewinding a little bit, it’s easy for me to say, you know, once you’ve assured that the COVID is clear of any debris, then you get the two by fours across top and bottom to kind of give yourself a path. And you you’re able to install that first piece of SNAP tight. As you said, let’s say you’ve got you know, 150 feet, I’m trying to recall if we’re talking 25 foot or 40 foot sticks upon 24 Yeah, so you know, you put that first one in, you snap, the second one, you push it forward. I guess two things where I was impressed with when I’ve been on job sites is one. I feel like some of these other manners require a pretty extensive training or maybe this doesn’t require as extensive training now, there’s being good at something and being okay at something. But but also in terms of the speed with which it can be installed is when you’ve got a really good crew doesn’t take a lot of time.

Don McGriff 

Well, some of the methods can go quick, but you know, when you talked about training, you know, typically with some of these methods, you know, if you’re the D O T, you’re the road crew, whatnot, you’re just gonna farm it out, sure, because you’re not going to buy the equipment, you’re not going to do all this stuff to do a CIP or folder for me just gonna farm it out. And what we tell people is, you know, everybody’s concerned about manpower. And DLT says, Well, I don’t have the time, I don’t have the manpower to do it. And I’m like, well, the same things we’re affecting, you’re affecting the contractors. So if you’re going to want to farm it out, you’re going to have to rely on a contractor who’s not, you know, so short handed, that they’re going to put you out and you can’t control it. So so we, we promote the fact that simplistic it’s something that typically needs backhoe or Traco to kind of help place it and snap it together. And then you’re going to do a little bit of concrete work whether it be the bulkheads or the grouting. You know, you mentioned something about boards, you know, boards are, are not always necessary. Okay. You know, sometimes, at least on the bottom was a snapshot, most of the ones we do we slot it straight in, even with a fairly deteriorated inverter you know, as long as it’s not gonna get hung up on something suppose bolts. Just just drop out in the bottom is so long that it can’t, you know, but if the, if the gasoline you know, 12 inches I got 24 inch by IP is just gonna slide along those corrugations. The top, you know, sometimes you’re going to put some some blocking in when you’ve got main entry, sometimes you need to strap the blocks to the pipe itself. So you don’t necessarily have to install it there. And that’s only when you want to try to keep it from floating to the top, sometimes inverts or the bottom, what we call the the bottom, inside diameter, the pipe the invert, you know, sometimes it doesn’t matter if it’s, it’s, it’s as this pipes of solids sitting up against the top of the other one. Sure. So sometimes that can make life easier, you just got to let the top of the pipe that probably hasn’t deteriorated, set the new lay of the pipe. So it’s not always even necessary that you have to do some of the things that we promote, you know, depends upon what your needs are. Job, Job,

Sean Moth 

the job, no makes sense. So with that, let’s imagine that we’ve done our snap tight, we’ve snapped together those 24 foot lengths, we’ve got a decent amount of leeway on either side, depending on what we want to do with it. Lace of grout tubes, basically at some different intervals there, get the cement and create the bulkhead, which basically is sealing in any the space between the existing pipe and the new pipe. Yep, let that cure, and then you’re pumping in grout and this grout is really pretty incredible material. Well,

Don McGriff 

it’s really simplistic, we can make it complex. But for depending on again, the complexity of the existing pipe, or host, you know, most of these things are running under two lane roads, 3040 50 feet, so that you could use something from a cement factory ready mix truck, you’re typically going to get something that’s low in aggregate. So you want something that cement water, cement, water and sand, cement water and fly ash, you know, less sand is probably better. But we promote a sailing route that’s typically, you know, advantageous when you’re doing long, big, just because you can develop some pressures, you can develop some, you want to make sure this stuff flows everywhere. So if you get too thick of a flow will fill a slurry mix slurry is kind of dangerous because sometimes those have a lot of aggregates. Neat mixes are another term, you know, it’s neat because it has no aggregate or low aggregate. So those things, you know, you can actually pour it out, if you’ve got access to the top end of the existing host, you can funnel a flowable fill or a neat mix into and let it just travel down and fill up. You mentioned you know, grout tubes, grout tubes are typically when we use to eject can be anything anywhere from one to a large number, depending upon the length the shirt, and how thick that grout mix is, you know, a lot of them turn and end up not being used. They’re just safety factors for one to clog. And we got to come back next day and start again, you know, do we have access to inject, we do like to have vent tubes, which are just short tubes on each end. And they turn they do let the air out. But they also serve as a verification on where that grout level is, as you’re filling up so that you can be certain with the most important would be at the top of the above the water pipe in between the ladder and host at the top at the inlet end. That’s your highest point. And once you get ground up to that level, you’re typically comfortable or confident that the grout has filled up most of the space if not all, you know. So grounding is is a little different from the some of the other learning methods, the grounding is basically most of the pipes that are installed are considered flexible pipes, flexible pipes, do well over the pipe soul interaction. We’re not using soul, we’re using grout just because it’s easier place easy to flow. And it has compressive properties that really are even higher than than soul itself. So we’re just adding a soul layer that happens to be Smith ground.

Sean Moth 

And obviously, environmentally friendly solution as well. It’s not gonna work

Don McGriff 

well, you got to make sure you control it. That’s probably where, you know, that’s where people probably experience most headaches was floodwaters I’ll be quite honest is, is you just don’t know where all the voids are. You think you might know, yeah, you go to grout, and you get some grout coming out in places that you don’t know. So I always try to make sure people think about their contingencies of, hey, what happens with Grant comes out someplace other than the tubes where I’m looking for them to come, you know, do you have a way to stop it? Do you have a way to to address it? Do you have a way to contain it? You know, concrete shoes all over place. So, you know, like, environmentally friendly is kind of depends on who you’re asking. Sure, sure. Environmentalists don’t like smitten their creeks. But you know, we’re building daily 1000s of things with concrete so yeah, it’s except

Sean Moth 

I’m guessing the the front end and the assessment becomes very crucial in that case that you’re aware of what you’re looking at before you put the solution

Don McGriff 

forward that and beyond your bulking. You got to be sure that you know when you put this what we call an NCO all the way around, you know, have I got it really compacted up underneath the lot in between the lines Under the host, especially where I can’t see very well, because once you go to start routing, you’ve got a big concrete truck there, you don’t want to stop, you want to be able for him to empty. And if you start getting grout flowing somewhere that you weren’t expecting. Again, that’s a lot more about preparation and understanding what the what it was before you started. Absolutely.

Sean Moth 

So as we move up to profile wall and spiral light, getting into larger diameters as well, just give me an overview of the difference between snap tight and spiral light, because I know there’s a lot of similarities, but there are differences.

Don McGriff 

Yeah, most people don’t know that, that we do have two different products that they’re used to us. For a number of years, we were manufacturing snap tight, it’s a solid wall pipe material, typically eight to 63 inches, our range on that that’s covered by the hashtag M 326. Standard. And that’s a snap together product, we’ve seen a male and female end so that when it snaps together, you get no change in the ID no change in the OD really works well for a lot of but at some point, you know, there’s a lot of coverts out there that go very large. And so we’ve been working with profile wall products, spotlight being chief among them, that are an ID based, and they go up to 120. Now they go, you know, as small as 18 inch. When we talk about covert lighting, we’re really talking about something that’s going to be 4248 54. Mainly because because they have an ad base, they may have some hydraulic advantage. But they’re going to have a bigger od a profile wall. It’s kind of like a corrugated, at least as far as how people might view it, they see this smooth interior, and kind of it’s got a smooth exterior, but it’s not as smooth as the interior. Sure, but basically what we’re doing is we’re laying a solid layer on a mandrel that mandrel size. If you want to make a six foot pipe, you have a six foot steel mandrel that can collapse out of the way. Once you’re done, you wrap a solid layer, then you wrap a core tube that spirals that’s the name and style spirals around the pipe that that core tube is sized with a diameter and spacing that gives you different strings so we can it’s an engineered product, it’s not like corrugated where what you get is what you get. And it either works or doesn’t we can definitely go very strong we can, we can do multiple layers of the core to bet as we need to. And then we do that solid layer on top helps us a lot with the slip lining process keeps that smooth exterior. We’ve done that now we used to manufacture with the exposed core to for some of our direct very, now most of it all is manufactured with a solid layer on top or smooth layer on top. It’s a bail speed connection so it’s not fully restrained joint both the snap tight and the spiral that have a gasket. The gasket for the snap tight is essentially keeping the ground out until things set up. And obviously we’ll keep the flow of the water in but the spotlight has a gasket connection but it’s the bell spigot so it’s got a little bit of a larger od in some cases, depending on the size not not terribly and then we might have to do some things we have a heat shrink, there’s some welding processes we can do to hold that pipe together because it’s normally meant to be a direct buried pipe. When we go to slip lighting we’re pushing and pulling we’re putting some different stresses on so the heat shrink or might be something that helps hold the joint through the installation doesn’t need for a seal because the gasket provides a seal but if you go to push something in and it wants to back off a little bit naturally or you can’t hold the pressure up against it or you need to pull back because you’ve hit something that joint will want to naturally come apart not an issue when you’re looking at direct bearing but for some lighting it’s a different consideration

Sean Moth 

and you talk about direct bearing because firelight wallet is outstanding for COBRA rehab has a number of of applications in terms of manholes and sewer in that yeah very versatile material it’s

Don McGriff 

been used for a lot of stuff long before we thought about putting it in for salt waters. A lot of sewer application combined sewer overflows retention detention make a lot of tanks out of it, you know going up to 120 inch we make a lot of detention tanks. So there’s a lot of applications for

Sean Moth 

it and oh mining geothermal vaults and it’s it’s really intriguing that

Don McGriff 

by that’s something I’ve been involved so make it something where it serves as a a structure, structural component to house some internal piping, things of that nature. You know, we actually make the aquatic A, we call it a Alp. The the term in the industry is AOP for aquatic organism passage. Yeah, we have an aquatic life passage pipe. We’re just trying to keep it separated so people aren’t totally confused. Yeah, but essentially what we do is we we make it but we don’t put that internal smooth layer so you get an internal corrugated product, it gives you a chance for sediment to build up to slow the water down. So you wouldn’t choose it from a hydraulic standpoint, but typically, that’s their their big concern. They wanted to go too fast for the fish or the crawdads or whatever it is that may be going from one side of the roadway to another. So you slow it down we can put Some baffling inside create some wrestling poles things of that nature. So we come back and use that product again, we find another engineered solution to help with that. But you know, it’s it’s something people need to set a week we do it for relining. But you could actually direct bury this, if you’re looking for a round solution that’s that’s economical. I tell people, the harsh reality is we can’t replace every culvert that’s failing with a bridge, we just don’t have the money to build a bridge everywhere, we want to build a bridge for fish for for raccoons for whatever it needs to cross from one side, sure, to the other. So this hopefully give some people options that they’d consider as

Sean Moth 

a fly fisherman, I definitely appreciate that. And, and I understand the logic too, I didn’t really touch on and I’m glad you brought that up, because I was going to head that direction. And we, we talk almost exclusively about piping, usually, when you’re in the HDPE world, he talks about wizened tees and fittings and that and it’s just not really something that has that. But one of the features is the hydro bill. And that’s something you put on the intake side. On snap side, I know that

Don McGriff 

I actually we didn’t talk a little talk about a month, but we’re developing capability to make one for the spiral out as well. So so no matter what pipe size, at least, maybe up to a certain point, we have some manufacturing limitations. So it might be a 96 inch or 84 inch where we top out but yeah, hydroboil is basically we’re replacing this with a smooth pipe we talked about a lot of people choose close fit liners, because hydraulic advantage, they view it as being hydraulically superior, and it may have some superior. But in essence, when you go with a snap Tod WhisperLite and you put it inside of corrugated metal, you’re going to improve the flow from a pipe capacity standpoint. So when people think my only option for hydraulically is a close fit modern, they haven’t looked at the Mannings comparison. Now, unfortunately, you know, hydraulics is not just all about the pipe, the pipe capacity, sometimes it’s controlled by how water gets into the pipe, how water exits the pipes called inlet control outlet control, very complex subjects, I don’t pretend to know as much as I want to about them. But you know, inlet control, basically, when headwater develops over the interests of the pipe, you get some sort of hydro liquid, and water just will not flow through, get into the pipe as efficiently as it needs to the hydro bill is essentially a funnel. Yeah, it helps funnel the water and so that you’re taking advantage of the full pipe capacity. Everybody says, Hey, how can I get more more flow through a pipe, and that’s kind of a misnomer. You can’t get more than the pipe can have the capacity to do from a from a planning standpoint, but you can’t help make sure that you’re using all the capacity, but by dealing with inland controlling, as far as I know, we’re the only lining solution that provides an inlet control option. So I think it’s worthwhile to consider, you know, it may be something that hydraulically, if you develop some headwaters, not a big deal, you’ve got enough depth on the side of the road, it’s not a concern. And to be quite honest, it may not be a concern, but except for that 20 year flood, or 50, or 100 year flood, you know, and that’s enough to create some damage. And it’s gonna help you know, it’s still gonna participate backup, possibly,

Sean Moth 

yeah, I know a lot of people really base their life on common sense and logic. And I mean, if you and I both had a container with a small opening, we were both pouring water into it. I had a funnel and you didn’t even know when, yeah, you know, and so the logic is there and that’s fantastic. So

Don McGriff 

my bear drinking friend. I say it reduces the glug glug

Sean Moth 

Well, phrase, well, phrase, I’m sure there’s plenty of college graduates that can identify with that one. Yeah. Let’s talk now just as we wrap up about the fact that, okay, you’ve selected snap tight spiral light for the install, we addressed flow rate, we’ve addressed the structure, just from an advantage standpoint, I feel like peace of mind is one of those two, that goes kind of under understated, because the life of this product 5200 years is going to keep a lot of headaches off

Don McGriff 

your cable. Yeah, well, one of the things that we really don’t talk about enough is what is the design life? Yeah, what’s the design life of a paid den Berg, I think, you know, you talk to people in the industry, you’re gonna get different answers, but there’s probably 510 15 years, you’ve extended life, you spent some amount of money. So we look at clothes fit liners, and again, they have their place, and they may have a 50 year design life if things things are installed properly, you deal with all the issues, you’ve got to the structural component address, got to fit to your design life and it cost you you know, 25% Less than a slip, slip water. But I’ve got 100 year design life I’ve got a pipe that normally is a pressure pipe 100 year design life, we moved this slop in it. It’s not been alive. It’s not been engineered. It’s not been a thing, except, you know, polyethylene was built in 1950. So we’re, what 75 years how do you get 100 year design life? It’s it’s the other complex math, the stress regression curves, but they know and we’ve advanced the material a lot in last 2025 years anyway, but we were feeling confident we got 100 years flatline. So okay, I’ve got to fit to your design life calls me 100 bucks. Foot, I’ve got 100 year design life cost me 150 bucks a foot. You know, in the end, did someone consider that as far as their design methodology, their design consideration, you know, sometimes you only got enough for 100 bucks a foot, you’re not gonna spend 150. But you know, I think most people, when they solve a problem, they like to solve a problem, make sure their children, their grandchildren don’t have to, to address it. So there is a design life component that we don’t talk about enough. That should be considered when when comparing alternates or options. Don,

Sean Moth 

I think that was a great piece of punctuation to set on this. And aside from that, I guess I’ll just see if there’s anything you want to add, because I really appreciate your time. I think it’s an intriguing subject. I’m from out west, I do a lot of driving and fly fishing in the mountains. And you just you can’t look left and right. Without seeing culverts all over the place. I know there’s a lot of work to be done. And hopefully we’ve given you some ideas of some of the solutions. And I want to encourage you that if you have questions about SNAP tight, or spiral light or slip lining, or maybe some other products to please visit our website and listen to our insights webinars and and find any information you can but anything you want to add.

Don McGriff 

Yeah, that’s, well, I like to give credit, I think it was a, an Alabama DLT, the head of the Alabama DLT talked about, you know, being a DLT employee as a good Sunday drops bald. And then same same for me, you know, that now when you’re driving, you hit a little dip in the road, you’re like, well, that’s probably a failing COVID. So, so things aren’t there. But I’d like to just add for the resources, you know, we can talk a lot about things. But we put probably, if we were honest about we put more information that helps all of our competitors, but the design manual, there’s design guide, technical guide, design manual, has everything that we’ve talked about from from a hydraulic from a structural from an install, from a grouting, we’ve revised that and published the latest revision March of this year, for a lot of work in that, and it’s, you know, it’s it’s really a go to resource for the whole industry. If somebody is doing flatlining, and they’re using polyethylene, I guarantee you, they probably looked at it and thought, that’s not a bad idea that that’s some good information. And then we have the install God, which is really meant it’s a pocket guide meant for the guy, it’s shaped, so that can fit in the back pocket. It gives a, you know, if I was doing a job, it’s got a material list. It’s got a method of work that’s in there that says, Hey, have you considered this? And what about routing and if it leaks, you know, the things that before they get started that would be good to address and, and has recommendations for for insulin or pipe effectively. Those two resources are probably more information is drinking from a firehose, but it’s, it’s worthwhile to someone who’s, who’s considering, you know, I’m intrigued by the snap tight. I have my concerns about these other methods. Let me learn a little bit more. I’ve done these other methods, but I’m not sure I’m getting the value for my money. Whatever it is, look at those and then give us a shout, we will go in the field, we’ve got to we’ve got rest and distributors spaced out throughout the country depends upon the relationships we had. And then myself and Ryan Harrington with ISCO will cover the southeast, the Midwest, and all the parts that our reps and distributors don’t cover and even go with them. We’d like to get out in the field tell you if we think we’re a good solution or not. We’re not going to we’re not going to put our products in place. We don’t think it’s good. It’s kind of savant.

Sean Moth  Absolutely not to sound cliche, but hey, we’re here to help and hopefully that was helpful. Don McGriff. Thanks so much for your time. Thanks for tuning into our insights podcast. Look forward to joining you next time. Take care