In the U. S. and Canada, you can call the toll-free “Digline” number at 811.
If you are digging a trench for electrical utilities or pipelines, dig at least 2. 5 feet (0. 8 m) deep in order to protect the pipes from frost, but no deeper than 4 feet. [1] X Research source The width of your trench will depend on your pipes, but will likely be narrow. If you are digging a trench for a sprinkler system, dig 9-12 inches deep and about 5 inches wide, depending on your sprinkler system. [2] X Research source
If you’re digging near trees, make sure that your trench will not invade the tree’s protected root zone (usually the part of the roots that lie directly below its branches). If you’re digging near pipes, try to determine where any other pipes may be. New pipes should be at least 1. 5 feet (0. 5 m) away from another.
If you run into roots, try to sever them with the pointed end of your shovel. If that doesn’t work, you may need a Pulaski digging tool. [5] X Research source Pruning shears are another good option, if your shovel fails and you do not have a Pulaski digging tool on hand. [6] X Research source
Some experts will dig unsupported trenches up to 5 ft (1. 5 m) in stable soil conditions. [7] X Trustworthy Source US Occupational Safety and Health Administration U. S. government agency responsible for setting and enforcing workplace safety standards Go to source However, follow the 3 ft (0. 9 m) rule if you do not have expert supervision.
To sever roots up to 1⁄2 in (1. 3 cm) thick, place the blade of your shovel on the root and stomp on the flange of the blade to sever it. For larger roots, consider purchasing a Pulaski digging tool. While mechanical trenching devices will usually sever roots, they may react violently or unpredictably when they encounter a thick one. Consider removing roots by hand before using a machine.
Debris like leaves and intrusions like growing plant matter might leave your trench looking less than tidy. Take time in spring and summer to keep it maintained. Plastic edging generally installs easily. Either lay it in the space you’ve excavated or place it in your trench with some light fill on top to keep it in place.
All ordinary trench safety precautions apply as well. This includes calling 811 or another utility location service before you begin, and having plans to shore up the trench walls if necessary.
Walk-behind trenchers can dig up to 3 feet deep and between 4-6 inches wide[11] X Research source [12] X Research source On average, a ride-on trencher can dig up to 7 feet (2. 1 m) deep and about 13 inches wide. Ride-on trenchers are usually only rented to professionals. Consider contracting a landscape company or a utility installation company to use this tool on your behalf.
Trenchers usually cost anywhere from $70 to $200 to rent for a day or two, plus the cost of transport. [13] X Research source You may also find a more affordable trencher through online services, like Craig’s List or eBay.
If you rented a trencher, be sure to ask for a demonstration of the machine’s operation, including a check that all safety and shut off switches are working properly. You should also have access to a copy of the manual, although you may be able to find this online by searching for the make and model information.
Large roots or stones might have to be cleared by hand. If your trencher stops for an unknown reason, turn the machine fully off, remove it from your trench, and clear any obstructions with a hand tool.
