It can be scary when you lack safety knowledge about putting water pipes and electric cables in the same trench. It's not a bad idea to save yourself from digging more trenches. We did our research to help you make that possible, and here's what we have to share.
Putting a water pipe and electric cable in the same trench is safe. The reason not to place them in the same trench is if you're planning to dig one of them out someday. Using a conduit and applying a suitable backfill may save the need for future digging.
Arming yourself with the proper precaution, you can safely run water lines and electric lines in the same trench. We'll delve into the specifics to secure good running utility lines in your trench, so keep reading!
How Putting A Water Pipe And Electric Cable In The Same Trench Affects Future Digging
Putting the electrical and plumbing in the same trench could give you a headache if your plumbing needs to be repaired. Consider what can happen if a negligent digger pulls up your electrical cable or conduit to access the plumbing.
The inspector's preferences and local laws may be the decisive factors. One trade may occasionally want to use the trench that another trade constructed. That's acceptable if your inspector is satisfied and the hijacker waits until the first one is finished.
There is a high chance of damaging the other if you dig up one of them without knowing it was there. Also, while repairing one line, you can unwittingly damage the other.
Even though a one-call locate would show both to be in the same trench, not everyone makes the call. Imagine hitting an electric line and water pipe in one hit; you might risk getting shocked.
What it takes to avoid striking two different services with a single pick swing could be considered reasonable clearance. We'll discuss this later in the measurements section.
Do I Need To Have A Professional Come Out Before Burying My Water Pipes And Electric Cables?
When performing electrical work, seek advice from the Authority Having Jurisdiction (AHJ). Contact your local electrical inspector if the AHJ is not immediately apparent.
Plumbing and electrical lines can be buried together in a trench without breaking any code since the National Electrical Code has no specific rule. However, the AHJ in your area may forbid or impose restrictions.
Such require that electrical cable or conduit be buried at least 24 "below grade and maintain a minimum 12" vertical distance between plumbing and electrical.
Also, it would help if you put plastic warning tape over cables or conduits in your trench. These are just a few examples of the restrictions that the AHJ may have in your area.
The Importance Of Using A Conduit
You can install PVC electrical conduit in the same trench you dig for your plumbing, with no wiring within the conduit.
Since digging trenches is labor-intensive, most people want to dig once. You won't need to dig trenches later on when you need to do electrical work when you can pull the wire through the conduit.
Placing them in the same trench, they should travel at various depths. You can divide your water pipes from the electric by placing a ledge on the ground in the trench. You can bury a conduit at a shallower depth than a direct burial.
Consider what else you could need in your home when a trench is open. TV cable, gas, switch wire circuit, 3 phase, ethernet cable, alarm.
You can use a draw wire in an empty conduit for any additional services you might want to pull. It is difficult and expensive to dig another trench later.
Can You Use Direct Burial Cables Without A Conduit?
Although it has greater depth requirements, you can use direct burial cables without needing conduits. Direct-burial cables (in the US) can handle up to 600 volts of AC.
Though you can't thread something through later as you might with conduit.
Most people assume they can snake something through the conduit later. But if conductors are already present, even with an additional drawstring, sometimes you have to remove everything.
You also have to push the new collection of wires through all at once, especially if your conduits have numerous bends.
How To Backfill A Trench With Water Pipes And Electric Cables
Each pipe or conduit run needs the proper bedding, which should be sand rather than jagged rocks to prevent piercing the pipe or conduit.
Also, while laying pipe or conduit at different depths, you should compact your backfill in layers, never going over 6 "each and might considerably be less. Usually, you'll be setting some 1-2 "of sand at the bottom of the trench. Thus there won't be much settlement.
The backfill beneath your electrical conduit will now be 12 or 18 "thick. The conduit will take a longer trip and experience tensile strains if that unevenly settles in different locations.
Sometimes, keeping a specific minimum vertical clearance is the only thing you'll need to do. It varies depending on your location.
Before you fill your ditch, roll out some red caution tape when it is still about 8 "deep.
Using Red Caution Tape For Trench Digging
You can try to dig your trench in a straight line (If possible) from point to point and backfill it.
Add some red caution tape, then cover it up so that you will dig up the caution tape if you ever have to get into the ditch again.
Water pipes must be at the depth necessary by your local code. This has to do with the frost line in your area, and a single trench is OK unless your local area demands otherwise.
The electrical should be installed roughly a foot above it, followed by the conduit for low voltage (ethernet, TV, alarm, and such) with a warning tape.
In this manner, if you are using equipment to dig, fingers crossed, you will primarily discover the tape. If not, you will strike the low voltage conduit, the higher voltage electricity, and finally, the water line.
How To Measure Your Trench
Water service not exceeding DN65 and low voltage (240V-415) electrical service must be separated by a minimum of 100mm. Internal measurement of pipe is referred to as DN. Consequently, create your trench at least 300mm wide.
Plumbing and electrical wires cannot come into contact with one another. Making sure these lines are adequately apart from one another is crucial.
As the ground shifts beneath the surface, they can still move slightly even after being buried in the ground.
These lines shouldn't touch because that could lead to wear and tear from friction. Additionally, you must avoid disasters since water and electricity do not combine.
Important Guidelines To Follow
If the trench is joint, you must keep the following distances in mind: 24 "between gas and electricity cables. Water must be 12 "away from the power wires. Electrical wiring and the sewer lines are separated by 24 ".
If the trench is only used for power, it must be large enough to fit the conduit; therefore, a 4" ditch-witch trench will do.
The conduit must be bedded with a minimum of 4 "of sand if the trench is dug through rocky, uneven ground.
Since they are all vertical and in the same trench, finding one is essentially as easy as finding all. You won't have to dig into another trench a few feet away.
It's tough to stack everything vertically when your water line is only buried 24" below. If your frost line is 2", in case you live in a region that doesn't freeze, it might be harder to bury utility lines in the same trench, even with spacing.
Placed in conduit, the electrical must be 18" or 24" deep. Water and electricity won't interfere, but putting them too close together could theoretically cause interference with the low voltage.
National Electrical Codes Explained
Whether or not you can run power and water in the same trench is not explicitly stated in the National Electrical Code.
Running both in the same trench will save time, but it may also result in significant maintenance issues in the future. In some areas, water lines are typically laid at a minimum depth of 8 "deep.
The NEC stipulates that UF cable must be buried at least 24 "deep in a trench. You will typically need to leave your trench open until your inspector arrives to approve the depth.
Some zones require water lines to be at least 750mm deep to prevent freezing. The power lines will likely be at 600mm or less.
Nothing is keeping you from placing the power cable in deeper. A conventional stepped trench with roughly 300mm horizontal separation is usually fine for low-voltage and water.
State authorities enforcing the local building codes may change your Uniform Building Code (UBC).
They may use a different version of the code than the one most recently enacted. It is, then, advised to inquire with them if you plan to pull a permit and have it inspected.
Safety should always be your top priority over hassling extra labor. You can use a joint trench as long as you follow the proper guidelines.
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