Trenching

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JoeNorm

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How do you small companies handle trenching? I am asking about residential jobs. It's obviously a big part of the work but can be a hassle to schedule and there are always unforeseen obstacles and a lot of risk involved. The older I get the less and less I want to dig by hand.

I see a few options:(1) rent the machinery and perform the work, (2)hire out the work to an excavation crew, or (3) have the homeowner handle all of it(however they want to get it done).

What has worked well for you all?
 
I have a tractor loader backhoe and the ability to move it, but honestly it's often not worth my time to deal with. Usually for me it's a mix of having the homeowner figure it out, or some of the gc's I work with have a guy they sub it out to. Of course if this is a bid job, you will need to have spelled out who is covering that cost.
 
I most times sub it out unless the HO wants to do it. On occasion, I have a small trench to do with another one at a different location. I can rent a trencher and do both trenches. I did two just this week that were 15 miles apart. I rented the trencher for a day but was able to return it and only have a half day charge. I charged each HO the full trencher cost instead of adding a haul charge.
 
Since I hate trenching I will attempt to get the HO, GC, or a sub to do it but sometimes I end up having to do it myself.

Here is my pro tip: If you have to do the trenching yourself, Use rigid conduit instead of PVC. PVC has to be buried 18 inches to the top. Rigid only has to be buried 6 inches to the top. That's a whole lot less digging and minimizes your odds of hitting an obstruction. Rigid does cost more, but you are eliminating 2/3 of your digging labor so it comes out about the same.

You might be thinking "but I don't want to thread rigid pipe". Well, you don't have to. Use compression couplings and connectors. You only need one compression fitting per straight run. Every other pipe in that run will use the factory threads and couplings.

"What about bends?" you ask. I try to minimize bends by keeping straight lines but some bends are inevitable. A hand bender will fairly easily bend 1/2-1" rigid. For bigger sizes, use factory bends. I once needed to do an offset in a two inch pipe that was better off bent. I took my pipe over to the apprenticeship school and used their Triple Nickel electric bender. You could also borrow the bender of a friendly EC as well.
 
I have a guy (sub) who does it. He owns a mini-ex.

He has a set price to dig and install the pipe, up to 50 feet. Per foot after that. 3-inch pipe is supplied and priced per stick, sweep 90s priced each.

Costs me $675.00 to get a 200 amp service piped in 50 feet and it's just one phone call.

I've found that's best, because he also keeps up on all 5 POCO requirements
 
I didn't do resi work, and the work I did I just rented equipment and dug it myself.

If I was doing resi work, I would give a price for the job w/out trenching and then give a price if I provide the trenching. I bet the customer would almost always take care of it. I would try to hire someone, but I would need to price it like I was going to do it (which is the most expensive way).
 
Coppersmith said:
Since I hate trenching I will attempt to get the HO, GC, or a sub to do it but sometimes I end up having to do it myself.

Here is my pro tip: If you have to do the trenching yourself, Use rigid conduit instead of PVC. PVC has to be buried 18 inches to the top. Rigid only has to be buried 6 inches to the top. That's a whole lot less digging and minimizes your odds of hitting an obstruction. Rigid does cost more, but you are eliminating 2/3 of your digging labor so it comes out about the same.

You might be thinking "but I don't want to thread rigid pipe". Well, you don't have to. Use compression couplings and connectors. You only need one compression fitting per straight run. Every other pipe in that run will use the factory threads and couplings.

"What about bends?" you ask. I try to minimize bends by keeping straight lines but some bends are inevitable. A hand bender will fairly easily bend 1/2-1" rigid. For bigger sizes, use factory bends. I once needed to do an offset in a two inch pipe that was better off bent. I took my pipe over to the apprenticeship school and used their Triple Nickel electric bender. You could also borrow the bender of a friendly EC as well.
Click to expand...
I'm interested in this method you mentioned, do you typically use ridgid from box to box or transition to/from pvc for your risers to make offsets easier?
 
I run rigid box to box, but there is no reason you couldn't transition to schedule 80 PVC for risers. Once the pipe is heading up, the burial depth is moot.
 
That (2017) requires a minimum cover of 18", which would defeat the purpose of using rigid to reduce the burial depth to 6".

Cheers, Wayne
 
There's an 250.86 Exception No.3 (2) also..
*Your posting #10 pertained to bonding covered raceway.
 
electrofelon said:
Which code cycle is this? Could you post it? I am a bit behind the times with the 2014 and I see nothing allowed to be floating except a 90.
Click to expand...
In 2017 Edition & 2020 Edition. 250.86 Exception #3 and those first three words via 2014 Edition (A metal elbow) having been removed.
 
(2017) 250.86 is below. I don't see anything that would allow an unbonded run of GRC with 6" of soil cover.

Cheers,
Wayne

250.86 Other Conductor Enclosures and Raceways. Except as permitted by 250.112(I), metal enclosures and raceways for other than service conductors shall be connected to the equipment grounding conductor.

Exception No. 1: Metal enclosures and raceways for conductors added to existing installations of open wire, knob-and-tube wiring, and nonmetallic-sheathed cable shall not be required to be connected to the equipment grounding conductor where these enclosures or wiring methods comply with (1) through (4) as follows:
(1) Do not provide an equipment ground
(2) Are in runs of less than 7.5 m (25 ft)
(3) Are free from probable contact with ground, grounded metal, metal lath, or other conductive material
(4) Are guarded against contact by persons

Exception No. 2: Short sections of metal enclosures or raceways used to provide support or protection of cable assemblies from physical damage shall not be required to be connected to the equipment grounding conductor.

Exception No. 3: Metal components shall not be required to be connected to the equipment grounding conductor or supply-side bonding jumper where either of the following conditions exist:
(1) The metal components are installed in a run of nonmetallic raceway(s) and isolated from possible contact by a minimum cover of 450 mm (18 in.) to any part of the metal components.
(2) The metal components are part of an installation of nonmetallic raceway(s) and are isolated from possible contact to any part of the metal components by being encased in not less than 50 mm (2 in.) of concrete.
 
250.86 Exception No. 3 (2) The metal components are part of a installation of nonmetallic raceway(s) and are isolated from possible contact to any part of metal component(s) by being encased in not less than 50mm (2inches) of concrete.
 
Dell3c said:
In 2017 Edition & 2020 Edition. 250.86 Exception #3 and those first three words via 2014 Edition (A metal elbow) having been removed.
Click to expand...
It is interesting they made the exception substantially less restrictive. I always assumed the elbow exception was to allow for steel elbows so pulling ropes wouldn't chew through them. I am kinda surprised you can run a mile of un-bonded rigid now, as long as it is 18 inches or deeper.

Although I agree with wwhitney this doesnt seem to help with the strategy in post #5. IMO concrete encasement is a huge hassle and if you're going to do that you might as well dig another foot.
 
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