Marking Conduit Trenches During Installation

[Electra_Glide]

Not that it was part of the question, but any time I'm running that sort of stuff in together like that, I try and be sure the electric is on the bottom. My logic is that, on the day somebody comes along and rips into it with their backhoe, they find the non-life threatening conduits first. (Ya never know--I might be the guy who rips it out too!) :eek2

In addition to what Digger said, also bury a layer of caution tape in the trench about 6"-12" above the conduit.

I can relate to what Digger's talking about. On our church project, my friend put in an electrical conduit between the bulding and the parking lot. I was there the day he did it, and helped him put the conduit in the ground. I came along about 6 months later to dig the trench for the water line, which had to cross under the electrical conduit. Since I had completely forgotten about the electrical condiut I'm sure glad he burried that caution tape... :eek2

Joe

 

[digger242j]

also bury a layer of caution tape in the trench about 6"-12" above the conduit.

We could probably have several entire threads dedicated to caution tape. While I agree with the recommendation for caution tape, I have to argue for more clearance. Personally, I don't think 6" is far enough above the conduit.

If you have *no idea* that there is conduit buried in your path, (and I mean no idea at all--you believe you have clear sailing for the next 200 feet of digging), do you really, consistently, take only the top 5 1/2" of dirt with each pass of the bucket?

Personally, I like to see the tape about 18" below the surface, and another 18" between there and the conduit, and sand around the conduit too. I've always felt that if you're only going to put 6" between the tape and the conduit, (and too many times there's not even that--I've dug the tape out from *under* the lines), then the tape should be printed with the emergency number of the utility company, because you're going to neeed it...

 

[CT18fireman]

I don't do a lot of that type of work, but when I have, even on a short run, I like to have the caution tape at least 15" above. I also try to cover the conduit with a different material then the surrounding fill. When you hit a different typ of material, especially if you have seen tape as well, you should be more careful.

 

[Dwan Hall]

Here electric is @ 36" and cable and phone are @ 28", water @ 5'. all are suspose to be bedded in sand and have cution tape 1' above.
if you dig it up by mistake and had a locate you only have to pay for the repairs but if you did not get a locate it is 3 times the cost of repair. if the locater was off more then 2' then the utility co. has to repair it for free, and I have charged them for my time lost.
I use to get $6.00 a foot for 2" and another $1.00 for each aditional inch, plus 1/2 more for each aditional piece of pipe. price has gone up a bit though. @ my old pricing your 300' of 3X4" conduit would be $20.00 per foot or $6000.00 plus equipment delivery.

 

[2004F550]

In my area tape has to be 6 inches above the conduit, that way everyone who knows anything is on the same page and knows what it means when you hit the tape.

 

[digger242j]

I'll ask again, my question above. If you have *no idea* that there is conduit buried in your path, do you really, consistently, take only the top 5 1/2" of dirt with each pass of the bucket?

I just did some searching, and it seems there are plenty of specs that the tape be 6"-12" below finish grade, or 12"-18" above the pipe or conduit. I doubt there are any that specify the tape be only 6" above .

 

[2004F550]

Well thats what the power company does around here and thats the way it has been, expect tape 6" above the conduit or in that range. And you shouldn't be digging if you don't have an idea of what is around and if you hit something its the diggers own fault. Get a call before you dig.

 

[digger242j]

And you shouldn't be digging if you don't have an idea of what is around and if you hit something its the diggers own fault. Get a call before you dig.

I won't argue that you don't need to call before you dig. There are times when owners fail to locate their lines though.

The city of Pittsburgh locates NOTHING. Sewers, water mains and services, electric lines for street lighting--none of it is ever marked. In the plan I'm most often working in now, I have a good idea of where the street light wiring is, but if *you* came in there to dig something, I bet you'd find the wire in the same bucketful of dirt as the warning tape. The gas company had their *own* people install a stretch of gas main, and 12 months later, they couldn't find it! The locator marked the water main with nice yellow paint that said 4" gas, but the gas main was 5' feet further away.

The reason I feel so strongly about this is that I've all too often seen markings that were not accurate, if they existed at all. As a member of *this* community--the folks who actually have to dig around the stuff without breaking it, one of the things I can do to help out my fellow excavators is to make sure that warning tape is placed where it'll actually provide *sufficient* warning. I don't want you to have to rely on the locator being able to get it right.

Well thats what the power company does around here and thats the way it has been, expect tape 6" above the conduit or in that range.

In the case Electra_Glide mentions, I wonder if the utility company would even have marked the line. Once it's on the private property, and outside the right-of-way some utilitiy companies may regard it as someone else's responsibility.

Anyone who's ever been in the operator's seat is welcome to answer this question: Are you personally convinced that that 6" will give *you* enough warning, if the locator makes a mistake, or fails to mark it at all?


(Note to Steve--we need a "soapbox" smiley....)

 

[Cat420]

It seems to me that 6" is plenty IF you are watching for utilities in the area. We usually dig a few inches and then have someone with a shovel clear the bottom to see if we are close to anything. If you are digging as if it was an open field, then 12" may not even be enough. So if I wasn't expecting utilities in the area, I might tear something up.

 

[2004F550]

I agree w/ 420, yesterday I had to dig up an exisiting conduit, the only way to be safe was to have a shoveler work with me the whole time and uncover the last couple inches etc.

 

[digger242j]

It seems to me that 6" is plenty IF you are watching for utilities in the area.

But, see, that capitalized "IF" is what makes my point. How productive can you be if you need to watch for utilities with literally every bucketful of dirt you take out of the ground? (Which is not to say that any of us just close our eyes and bail dirt out of the hole all day long, but you certainly slow down a lot when you have a *reason* to believe there's something nearby.)

Thursday and Friday I worked on a sewer lateral replacement on a house that's literally more than 100 years old. We found the water main directly beneath the sewer, seven feet behind the curb, and several feet into the driveway area of the house. Not exactly where we'd have expected it, and as I said above, the City of Pittsburgh ingnored the one-call.

The point in mentioning that is not that they should've put warning tape there 100 years ago, it's that, the work I install today will hopefully still be in service 100 years from now. My successors will hopefully have better locating help than I have today, but if they don't, I don't want to contribute to their headaches by not giving them enough warning that what *I* installed is there.

I think giving (or in the case of 2004F550's power company, specifying), only 6" is, shall we say, shortsighted.

 

[Nac]

When I started this tread I was just looking for some help in pricing and it seemed to go to a tread explaining which way to do the work. I know how to do the work, at this location I was told by the power company that they did not need a sand bed or backfill no trace wire or caution tape. Because it is there 10' utility easement and has allready been marked on ther maps for future markouts, Also that no should be diging there since it is on there easment. I just did a sewer and water service replacement yeasterday it should have been a fairly easy job so I thought. I called for a markout and all gas was marked from curb to the house and water was marked out just at the curb. I talk to the plumber installing the pipe work and ask to go in the basement so I can see were i have to start digging and the dept. That where I see that the water, sewer and gas are all on top of each other at diffrent depts. with the gas being on top. I go outside and the gas markout was at least 8' off to the right. So we start diging and uncover the gas, water and sewer but not sure if the gas crossed over to were the markout was we had to uncovera bit at a time diging next to it and clean off with a shovel what scoulde taken have taken 2 hours to trench took 5 hours.

 

[digger242j]

When I started this tread I was just looking for some help in pricing and it seemed to go to a tread explaining which way to do the work. I know how to do the work,

Funny how threads take on a life of their own that way, isn't it? I apologize for taking part in the "hijacking" of your thread. I do think this is a worthwhile discussion though. Somebody out there will be reading it one day in the future, and maybe learn something.

I was told by the power company that they did not need a sand bed or backfill no trace wire or caution tape. Because it is there 10' utility easement and has allready been marked on ther maps for future markouts, Also that no should be diging there since it is on there easment.

:Banghead

Like I tried to say earlier, how do any of us know what's going to be going on at these places in the next 100 years? I think whichever representative of the power company told you that is totally out of touch with reality.

The warning tape is not there to protect the concientious, diligent, intelligent, and situationally aware *excavator*. It's there to protect the *utility line*.

The best in the business will do it all by the book, and will have the experience and good instincts to know how to avoid doing damage to those lines. It's the clueless, or shoddy operators that the lines most need protection from. (I don't remember which thead it was in, but somebody here talked about an excavator who had the atitude of "Don't worry, I'll feel that line before I rip it out".) And, before you say that if the guy is clueless enough to not have bothered to call for a location, or paid attention to the location, or thought he could "feel" the line without doing damage, and deserves the penalty that'll befall him if he damages the line, think about whether the people whose lights will be out all night, or whose home is destroyed by a gas explosion are deserving of that.

I already said what I personally like as far as where the tape should be. I'll admit that I like it there because it gives *me* more of a margin of saftey, and I don't believe I'm one of the clueless. What I believe is that the purpose of the tape is to give at least a clue to the otherwise clueless. It's to keep *anybody* from digging through that line, and the threat to everyone else's well being that that entails.

 

[RonG]

I won't argue that you don't need to call before you dig. There are times when owners fail to locate their lines though.

The city of Pittsburgh locates NOTHING. Sewers, water mains and services, electric lines for street lighting--none of it is ever marked. In the plan I'm most often working in now, I have a good idea of where the street light wiring is, but if *you* came in there to dig something, I bet you'd find the wire in the same bucketful of dirt as the warning tape. The gas company had their *own* people install a stretch of gas main, and 12 months later, they couldn't find it! The locator marked the water main with nice yellow paint that said 4" gas, but the gas main was 5' feet further away.

The reason I feel so strongly about this is that I've all too often seen markings that were not accurate, if they existed at all. As a member of *this* community--the folks who actually have to dig around the stuff without breaking it, one of the things I can do to help out my fellow excavators is to make sure that warning tape is placed where it'll actually provide *sufficient* warning. I don't want you to have to rely on the locator being able to get it right.




In the case Electra_Glide mentions, I wonder if the utility company would even have marked the line. Once it's on the private property, and outside the right-of-way some utilitiy companies may regard it as someone else's responsibility.

Anyone who's ever been in the operator's seat is welcome to answer this question: Are you personally convinced that that 6" will give *you* enough warning, if the locator makes a mistake, or fails to mark it at all?


(Note to Steve--we need a "soapbox" smiley....)

I agree with you that 6" is just about useless if you expect to get any work done.........I expect a minimum of 12" or more.It is not fair to the contractor to be held hostage to some narrow minded "engineers" that make these rules for us to follow.Let me be narrow minded now and state that I had the feeling that 12" above the buried utility was pretty much universal among the utility companies and contractors who install them and even if it was two feet or more at least you stand a chance of finding it before you tear it out.
A properly installed utility trench will always have sand or some kind of fines around the utilities and it is not hard to dig through two feet of sand by hand if the need arises.You will only run into a problem if the trench is dug in sand originally and then you do have to be careful. Ron

 

[digger242j]

Just a waste of perfectly good orange polyethylene...

Just to take another whack at this dead horse...

Here's what it looks like when the warning tape is 6" above the conduit. The hole was dug to connect the gas service line. The curb stop is already installed, and there's just a little stub sticking out of it, which is the yellow object on the left. There is a gray conduit running across in front of the gas line, which is CATV. Just above it, at the far side of the hole, is the orange warning tape. I was aware of all this before I began to dig, so it wasn't really a factor, but the same stroke of the *shovel* that cut through the warning tape bumped into the conduit.

How's that going to warn a backhoe operator?

 

[digger242j]

Well, the red tape *is* 6" above the electrical conduit...

I don't even want to discuss it...

 

[DKinWA]

I'll throw in my two pennies for having the marking tape as close to the surface as possible. I don't do a lot of utility work, but the PUD requires the tape be placed just below the surface (not more than 6") here. Not too long ago I was talking to another contractor and he told me about the time they severed a fiber optic line that was marked incorrectly. When they pulled a tape, the paint marks were 12 feet away!!!! They weren't even close, so they were bailing out the trench and weren't looking for the line yet. Now if the tape were near the surface, they wouldv'e stood a much better chance of finding it before hitting it. Needless to say, the company tried to charge them for the breakage. In the end, it didn't cost them a dime.

 

[tylermckee]

we use detectable marking tape, 6"-12" below surface. i dont see too much benefit from putting it so close to the pipe. not gonna do you much good when you take a scoop and get a bucket full of warning tape and gas line

 

[Dusty]

IT is only supposed to be 6 inches below the serfice so u can find it i have ripped up things due to inproper marking