What Is Microtrenching?
Microtrenching cuts a narrow, shallow slot in pavement to place fiber conduit fast. See how it works and how it compares to HDD and open-cut trenching.
Microtrenching is an underground fiber construction method that uses a specialized saw to cut a narrow slot, typically 1 to 2 inches wide and 12 to 24 inches deep, into pavement or subgrade. Conduit or cable is placed in the slot, which is then backfilled and sealed at the surface, making it faster and less disruptive than conventional open-cut trenching.
How Microtrenching Works
A walk-behind or ride-on saw with a diamond blade cuts a slot directly into asphalt or concrete, usually along the edge of a road, sidewalk, or curb line. The cut is narrow, about 1 to 2 inches wide, and shallow compared to standard trenching, generally 12 to 24 inches deep depending on local specifications and existing utility clearance. Crews place microduct or conduit into the slot, often in a single pass behind the saw, then backfill with a sand or slurry mix and cap the surface with a matching sealant or cold-patch material. Because the cut is narrow, restoration is faster and the pavement scar is minimal compared to full-width trenching.
Microtrenching vs. HDD
Microtrenching and horizontal directional drilling (HDD) are both alternatives to full open-cut trenching, but they work differently. Microtrenching does cut the surface: it leaves a continuous, narrow saw-cut along the entire route that must be backfilled and resealed. HDD avoids a continuous open trench altogether. A drill rig bores a path underground between entry and exit pits, so the surface between those pits is not disturbed. Contractors choose microtrenching for shallow, paved corridors where speed and low restoration cost matter, and choose HDD for crossings under roads, driveways, or landscaping where even a narrow surface cut is undesirable, or where depth and soil conditions call for a bored path.
Where Microtrenching Is Used
Microtrenching is common in fiber-to-the-home and fiber-to-the-business builds along paved streets, sidewalks, and parking areas where installing fiber quickly with minimal traffic disruption matters. It works best in stable pavement with well-documented utility locations, since the shallow depth leaves less clearance from existing gas, water, or power lines than a conventional trench. It is generally not suited for unpaved rights-of-way, unstable soils, or routes with dense existing utility conflicts, where open-cut trenching or HDD may fit better. Local permitting authorities often set specific depth, width, and restoration standards for microtrenching, so engineering and permitting review is a standard first step before construction begins.
Microtrenching, answered
What Is Microtrenching?
Microtrenching is an underground fiber construction method that uses a specialized saw to cut a narrow slot, typically 1 to 2 inches wide and 12 to 24 inches deep, into pavement or subgrade. Conduit or cable is placed in the slot, which is then backfilled and sealed at the surface, making it faster and less disruptive than conventional open-cut trenching.
How deep is a microtrench?
Most microtrenches run 12 to 24 inches deep and 1 to 2 inches wide, though exact dimensions depend on local right-of-way rules, pavement type, and clearance from existing utilities. Engineering and permitting review typically confirms the required depth before construction starts.
Is microtrenching the same as directional drilling?
No. Microtrenching saw-cuts a continuous narrow slot into pavement along the route. Directional drilling bores underground between entry and exit pits without a continuous surface cut. Contractors choose between them based on pavement conditions, utility conflicts, and how much surface disruption a project can tolerate.
Does microtrenching damage pavement?
It leaves a narrow saw-cut scar, typically 1 to 2 inches wide, that gets backfilled and sealed after conduit is placed. Properly restored, the cut blends into the pavement, but the road surface is cut, unlike a bore that avoids a continuous open trench.