What Is Underground Warning Tape?
Underground warning tape is a buried marker strip that warns excavators before they hit fiber lines. See how Fiber Construction Company installs it.
Underground warning tape is a brightly colored, printed plastic strip buried a foot or so above a fiber or utility line as a last-line warning to anyone digging later. It marks the presence of buried cable before a shovel or excavator bucket reaches the line itself.
What the Tape Is Made Of and What It Says
Underground warning tape is a plastic strip installed in the trench above a buried fiber line, printed with repeating text like "CAUTION: BURIED FIBER OPTIC CABLE BELOW." Most tape used on fiber jobs is detectable tape, meaning it has a thin metallic foil core that shows up on a cable locator even if someone digs without calling for a locate first. Non-detectable tape is plain plastic with no foil and relies only on someone actually seeing it while digging. Fiber Construction Company specifies detectable tape on underground builds so the line has a backup warning layer beyond the printed message itself.
Why the Color Matters
Color matters. The American Public Works Association color code marks communications lines, including fiber, with orange tape and orange-jacketed conduit. That color code is standard across most utility locating programs, so a crew hitting orange tape in a trench knows to stop and check for a communications line before going further, even before reading the print. Using the wrong color, or skipping tape entirely, breaks that visual chain and raises the odds of an accidental hit on a later dig.
Where It Sits in the Trench
Placement follows a simple rule: the tape sits above the line, not on it. Crews typically backfill partway, lay the tape roughly 12 to 18 inches below finished grade, then finish backfilling. That gap gives whoever digs next a warning before their equipment reaches the actual cable, whether they are hand-digging with a shovel or running a trencher. Tape is a backup, not a substitute for calling 811 and getting the line located and marked before any excavation starts.
Underground Warning Tape, answered
What Is Underground Warning Tape?
Underground warning tape is a brightly colored, printed plastic strip buried a foot or so above a fiber or utility line as a last-line warning to anyone digging later. It marks the presence of buried cable before a shovel or excavator bucket reaches the line itself.
Is warning tape the same as locate tape?
No. Warning tape is buried in the trench as a permanent marker for future digging. Locate tape (or locate flags and paint) is a temporary, above-ground marking used during an active dig to show where 811 has located a line before excavation begins.
What color is fiber warning tape?
Orange, following the American Public Works Association color code for communications lines. Fiber Construction Company uses orange detectable tape on underground fiber installs so crews recognize it as a communications warning at a glance.
Does warning tape mean you don't need to call 811 first?
No. Warning tape is a backup, not a replacement for a locate request. Always call 811 and get lines marked before digging, even in an area where tape might be present.