How to Trench a Cable Line

Burying a cable line is the surest way to protect it from damage or accidental disconnection. It is necessary to dig a trench to bury it at a safe depth. For short distances, a shovel is generally good enough to dig the trench. But for longer distances, a power trencher saves time and exhausting digging. Some cable companies trench their own wires, but homeowners running their own line must trench it themselves.

Things You'll Need

• Spray paint
• Tape measure
• Cable line
• Utility knife
• Wire cutters
• Power trencher
• Shovel
• Garden hoe
• Tamping tool
• Scrap lumber
• Grass seed
• Sod

Instructions

1. Contact the local utility companies, and arrange for them to come and mark the location of buried lines with flags and spray paint. This makes it possible to choose the area to run the cable line, without risking accidentally cutting through an already placed utility.

2. Walk a path from the main cable junction box to the location for the connection to the building, and make a spray paint line on the ground to show the path. Choose the shortest and straightest course possible that won't intersect with any existing utility lines underground.

3. Measure the length of cable line needed to reach from one point to the other. Add 2 feet and cut the cable line with a utility knife or wire cutters. Set aside the cable.

4. Rent a power trencher from a tool supply rental store. Set the trenching blade for a 4-inch depth, and position the machine and blade over the center of the paint. Turn on the trencher and engage the blade. Slowly lower the blade, and begin walking the paint path until complete. Raise the blade and switch off the trencher.

5. Drop the cable line into the trench, and spread it out through the entire length. Leave an equal amount free on both ends of the trench.

6. Fill the trench with the dirt left to the side by the trencher. Use a shovel or hoe to push the dirt back in, and tamp it down with a tamping tool or piece of scrap lumber. Cover the trench line with grass seed, or add sod as necessary.

Tips & Warnings

• Lay a 1-inch diameter length of PVC pipe in the trench to feed the cable line through, if you want to protect it from accidental cutting.

• In very cold areas, consider trenching twice as deep to get the cable below the frost line.

• Only operate the trencher from behind, and make sure no one is in the path during operation.

References

• "Audio/Video Cable Installer's Pocket Guide"; Stephen H. Lampen; 2002
• "Black & Decker: The Complete Guide to Landscape Projects"; Kristen Hampshire; 2010