How to dig the narrowest 3' deep trench or minimize sand fill for a wide trench?

[BackRoad]

Rented trencher, over 1000 feet in clay soil. Took less than 2 hours.

Digging 2 trenches would be a day's rental. You may have mention depth required. This got down 3'...

 

[future_vision]

Would it be possible to simply use a 6" ditch witch trencher? It should be a lot faster than an excavator. SAND? What a pain, but you should be able to handle it. Perhaps you could make a tool to lay the sand into the ditch.

If it was me, I'd do two separate narrow trenches with the ditch digger and keep your power and telecom completely separate.

I mentioned this as a consideration in my OP. It'll be $309/day plus finding a way to transport it. Then there is New England ground filled with granite. Just when you think you are in the clear you hit a big rock(s). If the trenching was the only thing I was doing then maybe I give this a go and use the backhoe on my tractor when rocks are encountered but sometimes they are really big and 60hp tractor even struggles. Now, before anyone says anything, I've considered doing the trenching with my tractor. I thing I would be fine with it 3/4 of the way but I just can't maneuver it in the woods and on the hill to effectively, or safely, dig a trench. The CAT 36 is a bit wider than the tractor and will also struggle a bit to fit the path but with the reach it has and the blade I can probably get where I need to go. I'll find out tomorrow when it is delivered. Should be interesting. I don't have a good track record with excavators+trees.

 

[future_vision]

Rented trencher, over 1000 feet in clay soil. Took less than 2 hours.

Digging 2 trenches would be a day's rental. You may have mention depth required. This got down 3'...View attachment 4316533View attachment 4316534

That would be perfect other than what I described in the original post and the one before this. I am coming up a hill from the pole and then shooting over diagonally and up a the rest of a hill in a wooded area. I think I would probably be ok considering the tracks but I would be looking at additional dollars and if I hit those big rocks, which is almost inevitable, I'm in there with the excavator. Who knows. Maybe I will find a local place that has one that will be cheaper to rent and closer than Home Depot and try and come up with the extra $$ to get it.

 

[dodge man]

I feel like I’m missing something. I just roughly figured you would need a couple tandem loads of sand. I’m a hack on a mini ex and I think I could dig 300 feet of trench in half a day. I don’t see where this is that expensive.

 

[paulsharvey]

I feel like I’m missing something. I just roughly figured you would need a couple tandem loads of sand. I’m a hack on a mini ex and I think I could dig 300 feet of trench in half a day. I don’t see where this is that expensive.

The way I see it, the sand is a light bedding, not the back fill; so a 24" trench, with 6" of clean fill; thats about 12 CY, or 2/3rds of a truck if you can't just dig the sand from a hole in the woods. Maybe 24 CY if you truly lay 6" of sand on the entire bottom, play the pipe and lay another 6" on top.

Does the power company's want to see the conduit prior to pulling wire? Telecom very likely doesn't care at all

 

[Happy in NC]

The fiber company put in my fiber at about 6" free as part of the install. Why not drop the electric in then let them trench fiber parallel or just above the electric line? Just a thought

 

[Rctex]

Ok. I am deferring to the power of group think here. Here is my situation. I need to trench 300' for electrical and telecommunication conduit. Electrical is 3" wide conduit and telecommunication will be 2" conduit. The minimum depth for electrical is 30". I am trenching from a pole that is pretty much in the drainage ditch next to the road and up a hill. I am guessing I'll start somewhere around 36" at the pole and be around 3-5' deep when I start ascending the hill. Over a certain number of feet I'll eventually get back up to the 30" (36" to be safe). I think I got that all worked out. Here is my issue. The electrical service is asking for a bed of sand(or stone dust) below the conduit and 12" above. I can't get any answer out of the fiber internet company so I was going to do the same for their conduit. No problem but here is the issue. The telecommunication conduit needs to be 12" away from the electrical. If I dig a wide trench to accommodate both conduits and the spacing, I am looking at a minimum 17" wide trench. Realistically it'll probably be closer to 20". Ok. So what is the problem? The problem is the 12" of sand on top of the conduit. How do I get 12" on top of both conduit and not have to buy a ton of extra fill for the 12" gap in between? I had considered renting a trencher but that might be a little treacherous on the slope and I would need to put a much large gap in the rock wall to navigate through. Plus, being in New England, I'll likely hit some large rocks. Then what? It's not like you can just bend 3" around them or dig multiple new trenches hoping to find a clear path. There is also the fact the electric company only allow a certain amount of bend in the run and I already need to do a 45 degree turn at one point.

A trencher, that can go that deep, is about $310/day from Home Depot. I'd have to do some serious looking to find one somewhat local for cheaper. The easy route is just do the wide trench with the CAT 306 but the cost of filling that 12x12x300 area, in between conduits, is prohibitive.

Dig the ditch…..install electrical……once it’s passed out the 2” in right on top of sand covering the other conduit
I mean once it’s passed who’ll know what’s under it

 

[vallefarm]

Hmm. Two problems with that. One is that having the telecommunication line on top of the electric means that i need to navigate that line if I need to get to the electrical below. I'm not sure I really want to do that. Second, the sand is intended to protect the conduit from rocks when/if compaction occurs. Do I really want to protect the electric and not the telecommunication conduit? I really wish that the fiber company can give me install instructions. They just don't have them available. I kept getting bounced around on two different occasions. Eventually, they submitted a ticket to one of their divisions. I am not keeping my hopes up I'll get any guidance. I'm considering calling a competitor that runs co-ax. Probably Xfinity. See what they say

What do you mean by navigate that line? If you mean you are concerned with digging that close just get as close as you want then use a power washer and drill till you see them. Now you know where they are exactly and did no harm to them.

 

[LittleBittyBigJohn]

Hmm. Two problems with that. One is that having the telecommunication line on top of the electric means that i need to navigate that line if I need to get to the electrical below. I'm not sure I really want to do that. Second, the sand is intended to protect the conduit from rocks when/if compaction occurs. Do I really want to protect the electric and not the telecommunication conduit? I really wish that the fiber company can give me install instructions. They just don't have them available. I kept getting bounced around on two different occasions. Eventually, they submitted a ticket to one of their divisions. I am not keeping my hopes up I'll get any guidance. I'm considering calling a competitor that runs co-ax. Probably Xfinity. See what they say

It's not as serious as it sounds. Power always wants to be on bottom. My power company specifically told me vertically is 100% ok so long as they are on bottom, they actually brought it up first. Out here in the rocky parts the power and data people go straight in the ground with no sand, rocks and all. You can still put sand around both even if they are stacked instead of side by side.

 

[mike8149]

This is probably not workable but can you go overhead for both or overhead for electric and wireless for cable/voice/data.

 

[TORQUIN]

If renting a trencher from Home Depot, verify that it will go deep enough first, then test it as soon as you get home. I rented one from Home Depot back in 2016, that was supposed to be able to trench to 28", for my gen set wiring. In reality, it was unable to get to that depth. I had to finish the job with my back hoe. Home Depot gave me a refund on the rental since the equipment could not do the job.

Chris

 

[bgr]

As a fellow new englander, I am sure you will see a few big rocks, and also a lot of small and medium ones mixed in your backfill soil. Sand is your friend because you can backfill it by machine. If you use your backfill, you will have to do it by hand for the first 12 inches because you will want to sort out the rocks from the soil going onto the conduit. That is a lot of work. Use the 12 inch bucket to trench.

My electrical inspector would want to see the trench with 2 inches of sand under the conduit and 12 inches on top, plus the caution tape laid directly above the conduit on top of the backfill sand. He would want to see some parts of the trench completely backfilled with the tape in place and every 30 feet or so, backfill left out to show the conduit. If you have an inspection, I would ask the inspector what he wants to see before you start. Be sure to use caution tape with a metallic element so the trench can be found with a locater.

I think the idea of having the fiber people pull in their line after you finish the trench is a good one. You would have to be sure one side of the trench backfill was smooth and rock free to accommodate their trenching or pulling machine after you were done. or you could lay the fiber on top of the sand backfill on the opposite side of the trench from the conduit, AFTER your inspection is complete. My inspector always wants the visible sections of conduit to have the maker's logo on top and visible where the conduit is exposed.

The sand required would be 1.2(foot) x 1(foot) x 300(Feet) = 360 cubic feet. divided by 27(cu. ft. in a yard) = 13.3 yards. I would get 20 yards, or whatever your supplier's truckload is, as you can always use a little extra in case the trench is not a perfect 12 x 12 shape in some spots and it is faster not to carefully ration it.

You are going to need a teenager to help spread the sand evenly as you drop it in if you can find someone. I have found it quicker to do the 2 inch base of sand in the whole trench, go back and glue the conduit out of the trench, roll it in in one piece for the whole trench, then go back and put in the 12 inches of sand. That puts less strain on the fresh glue joints, and makes sure the conduit is clean, with no sand in it. Be sure to tape the ends closed before rolling it in. Tap the conduit sections together with a light sledge and a wood block over the ends as you glue it. The joints on 20 foot sections are deep and you want to be all the way in for strength But you will find your own system. Always look down each piece of conduit for no obstructions before you glue it.

My instructions are detailed because every detail comes from a screw up. Hope your job goes well.

 

[orezok]

Being a licensed General Contractor for 35 years, I would NEVER stack high voltage, low voltage lines vertically. Thats a future NIGHTMARE!

 

[thclimer]

Prior to where I now live I lived in NY near the Canadian boarder, north of Plattsburgh. In that area I would dig a hole or a trench which would consist of 30-50% rock. Anywhere from baseball to bathtub sized, just crazy. Good luck keeping your lawn free of rocks as each year the frost would push new ones to the surface.

 

[John_Mc]

Not sure where you are located, but in my area, sand is cheap. Just as a rough calculation: let’s say you need a total depth 16” of sand (to get some under and the 12” over, and your trench is 17” wide and 300’ long. That’s about 21 yards.

Even if I’m off and you need to go 20”x17”, that’s 26 yards. A full load in runs about 13 or 14 yards in the dump trucks our town road crew use (which are the same thing most gravel and sand suppliers in our area use.) I’d just get two loads of sand delivered and dig the trench with an excavator. (I’ve run walk behind trenchers and they are a pain in the butt here in Vermont’s rocky soil.)

 

[Gord Baker]

Ok. I am deferring to the power of group think here. Here is my situation. I need to trench 300' for electrical and telecommunication conduit. Electrical is 3" wide conduit and telecommunication will be 2" conduit. The minimum depth for electrical is 30". I am trenching from a pole that is pretty much in the drainage ditch next to the road and up a hill. I am guessing I'll start somewhere around 36" at the pole and be around 3-5' deep when I start ascending the hill. Over a certain number of feet I'll eventually get back up to the 30" (36" to be safe). I think I got that all worked out. Here is my issue. The electrical service is asking for a bed of sand(or stone dust) below the conduit and 12" above. I can't get any answer out of the fiber internet company so I was going to do the same for their conduit. No problem but here is the issue. The telecommunication conduit needs to be 12" away from the electrical. If I dig a wide trench to accommodate both conduits and the spacing, I am looking at a minimum 17" wide trench. Realistically it'll probably be closer to 20". Ok. So what is the problem? The problem is the 12" of sand on top of the conduit. How do I get 12" on top of both conduit and not have to buy a ton of extra fill for the 12" gap in between? I had considered renting a trencher but that might be a little treacherous on the slope and I would need to put a much large gap in the rock wall to navigate through. Plus, being in New England, I'll likely hit some large rocks. Then what? It's not like you can just bend 3" around them or dig multiple new trenches hoping to find a clear path. There is also the fact the electric company only allow a certain amount of bend in the run and I already need to do a 45 degree turn at one point.

A trencher, that can go that deep, is about $310/day from Home Depot. I'd have to do some serious looking to find one somewhat local for cheaper. The easy route is just do the wide trench with the CAT 306 but the cost of filling that 12x12x300 area, in between conduits, is prohibitive.

I recommend getting it professionally done. 2 trenches. 36"+ deep. Carefully Map out where they run. In Ontario a Red Marker tape is required a foot above the conduit. A good idea even if not required by Code.
You might also ask your phone company if they have a contractor that would Bore it Out. 3" seems too big for a simple power and/or communications conduit.

 

[CliffordK]

When we had our copper telecom wires put in years ago the phone company used a knife type cable layer. One pass just putting the wires down. No conduit, although I see some conduit laying solutions online. I still would try to keep water, power, and telecom all separate.

 

[future_vision]

The way I see it, the sand is a light bedding, not the back fill; so a 24" trench, with 6" of clean fill; thats about 12 CY, or 2/3rds of a truck if you can't just dig the sand from a hole in the woods. Maybe 24 CY if you truly lay 6" of sand on the entire bottom, play the pipe and lay another 6" on top.

Does the power company's want to see the conduit prior to pulling wire? Telecom very likely doesn't care at all

They specified a 'bed' of sand and 12" on top although it is not in their official documentation. I need to talk to the field guy again and see if they have any ideas about minimizing that amount. They did want to see it but if it is the same guy then he is really cool. Might give me a pass if I am not spot on or just mound the sand on top until it is close.
.

 

[future_vision]

If renting a trencher from Home Depot, verify that it will go deep enough first, then test it as soon as you get home. I rented one from Home Depot back in 2016, that was supposed to be able to trench to 28", for my gen set wiring. In reality, it was unable to get to that depth. I had to finish the job with my back hoe. Home Depot gave me a refund on the rental since the equipment could not do the job.

Chris

Ended up being a hard pass on a trencher even though HD has ones the would do 36" and 48". With the soil up here you never know what you will hit. Glad I did because I've been hitting rocks that would have stopped the trencher in its tracks. Not a lot but enough that I would have had to go around them and that just won't work with 3" conduit.

 

[miscjames]

What we did was just rent a trencher the kind on a tractor and pulled it along with a chain with a backhoe (you use the 306) in the bad up hill spots (. 2 person job of course.) If you hit abad spot bounce over it and keep going. Then come back and dig that part out with the 306. Then come back with 306 and bury it. You Will surprised how fast it goes we did 450yards this way up hill. And got it done and in a day