How To Install Landscape Lighting Under Sidewalk?

When you're putting a landscape lighting setup together, one of the most important things to think about is how to hide the wiring.

Exposed cable spoils the look of your outdoor space, and it's a trip hazard. Most landscape lighting cable is rated to be buried — but what do you do when the run has to cross a sidewalk or driveway?

This guide covers three methods, plus the safety steps to take before you put a shovel in the ground:

• Flexible drill boring under a sidewalk (minimal digging)
• Hammered metal pipe sleeve under a sidewalk (built-in wire protection)
• Expansion-joint routing across a wider concrete driveway

📝 A scope note: this article covers low-voltage (12V) landscape lighting systems running off a plug-in transformer. The methods below are not appropriate for 120V branch circuits, which require deeper burial, listed conduit, and almost always a permit and a licensed electrician.

Before You Start: Safety Essentials

Call 811 before you dig

⚠️ Call 811, or submit a request through your state's 811 website, at least a few business days before any trenching. The service is free, federally mandated, and the operator will mark buried public gas, electric, water, and telecom lines so you don't hit them. One caveat: 811 only marks public utilities. Existing private lines (irrigation, landscape lighting, gas to a grill, electric to a shed) are your responsibility, if you suspect any are in the area, hire a private utility locator.

Use direct-burial-rated cable

Only cable that's specifically UL-listed for direct burial is safe to put underground. Look for "direct burial" stamped on the jacket — common low-voltage ratings are 12/2 or 16/2 (gauge / number of conductors). Standard lamp cord, zip cord, or extension cord is not rated for burial and is a real fire and shock hazard if you bury it.

GFCI outlet and waterproof splices

Per NEC 210.8, the line-voltage outdoor outlet feeding your transformer must be GFCI-protected. Any splice in buried low-voltage cable must use a waterproof connector listed for direct burial — silicone-filled "gel" wire nuts are the standard product. Don't use indoor wire nuts or electrical tape on a buried splice.

How To Run Landscape Lighting Wire Under a Sidewalk

There are two main options for running landscape lighting wire underneath a typical sidewalk. The right choice depends on how much digging you want to do and whether you need built-in wire protection.

Method 1: Flexible Drill Boring

What you'll need:

• Flexible drill bit (Amazon) long enough to span the sidewalk
• A standard household drill
• A shovel for the small starter trenches on each side
• Direct-burial low-voltage cable

1. Remove a section of grass on each side of the sidewalk until you can see the bottom of the slabs. You only need about 12 inches of trench on the side you're drilling from.
2. Place the drill bit under the slab, flexing it just enough to keep it level, and drill slowly to start boring through.
3. If the bit hits stubborn debris, reverse a few inches and try again. Slow and steady wins here — pushing too hard makes it easy to angle off and surface in the wrong place.
4. Once the bit emerges on the far side, tie your wire to the dedicated hole at the tip and pull the bit (and the wire) back through.

Method 2: Hammered Conduit Boring

The alternative is to drive a length of metal pipe under the sidewalk. The pipe acts as both a boring tool and a sleeve, so the wire ends up protected.

A note on materials: bare or galvanized steel will eventually corrode underground. For a one-time bore where you just need to get cable across, that's fine — the pipe is doing its job whether or not it survives long-term. If you want a permanent wire-protection conduit, PVC Schedule 40 is the more corrosion-resistant choice — drive a steel pipe to bore the hole, then pull a PVC sleeve into place using the steel as a temporary guide.

What you'll need:

• A length of metal pipe about 12 inches longer than the width of the sidewalk
• A sledgehammer or large hammer
• A shovel for trenching
• A hacksaw to trim the pipe end after boring
• Direct-burial low-voltage cable
• Waterproof, direct-burial-rated wire connectors if you'll be splicing

1. Dig a trench along one side of the sidewalk that's the full length of the pipe, plus another six inches behind it for hammer clearance.
2. Crimp the leading end of the pipe into a wedge or chisel shape — flatten it down with the hammer until the opening is pinched closed. The wedge cuts through soil instead of scooping it up, and stops the pipe from clogging with dirt as it advances.
3. Lay the pipe in the trench with the wedge end against the soil under the sidewalk.
4. Drive it through with steady taps from the back end. Don't over-swing — a bent pipe is much harder to push through.
5. Once the wedge end emerges on the far side, cut it off with the hacksaw, leaving an open sleeve.
6. Feed the direct-burial cable through. If you spliced the cable to make the run, use waterproof, direct-burial-rated connectors at every splice.

Drill Bit vs Hammered Pipe: Which to Choose

How Deep Does Landscape Lighting Wire Need to Be Buried?

Per NEC 300.5, low-voltage landscape lighting cable (30V or less) only needs 6 inches of cover in most areas, increasing to 18 inches under residential driveways and parking areas. The 18–24 inch figures often quoted online apply to standard 120V branch circuits, not low-voltage lighting. Manufacturer instructions for a specific listed system can sometimes allow even shallower depths.

Under a sidewalk specifically, depth is less of a concern — you're not going to put a shovel through a concrete slab by accident. Burial depth rules exist mainly to protect against accidental digging, and the slab itself does that for you.

A sleeve under the sidewalk is still worth adding if you want to future-proof the run — for example, if the slab might be jackhammered up someday and you don't want to rediscover the cable the hard way. The hammered-pipe method gives you that sleeve as a side effect, which is one of its main advantages over the drill-bit approach.

Method 3: Crossing a Wider Concrete Driveway

A wide driveway breaks both sidewalk methods. You won't find a flexible drill bit long enough, and you can't trench far enough alongside it to keep a hammered pipe level. Rather than trying to go under, the trick is to go through — specifically, through an existing expansion joint.

Concrete driveways have expansion joints built in to absorb seasonal expansion and contraction. They show up as thin gaps running across the slab, filled with something compressible. In modern construction the filler is usually asphalt-impregnated fiberboard, closed-cell polyethylene foam, cork, or polyurethane sealant. Older driveways may have something similar — felt and bare wood are essentially never used today.

What you'll need:

• A utility knife or thin saw blade to cut the existing joint filler
• Direct-burial low-voltage cable
• A short length of small-diameter PVC conduit to sleeve the cable across the joint
• Polyurethane expansion-joint sealer (Amazon) to re-seal the gap

1. Find a joint that runs in a useful direction for your cable path — usually the one nearest where you want to come out on the other side.
2. Cut down through the existing filler with a utility knife or thin saw blade. Go slowly so you don't chip the slab edges.
3. Slip the cable into a short PVC sleeve where it crosses the joint. The slab moves a little with temperature, and an unsleeved cable can chafe through over time.
4. Lay the sleeved cable in the gap.
5. Re-seal the joint with a polyurethane expansion-joint sealer. This keeps water from getting under the slab and undermining it.

FAQ

Choosing the Right Method

Across a narrow sidewalk with one cable run, the flexible drill bit is fastest and the cleanest to clean up after. If you need to pull multiple cables across the same crossing — or want long-term wire protection without coming back to it — the hammered-pipe method is worth the extra digging. For a wider concrete driveway, working through an existing expansion joint sidesteps the impossible boring problem entirely; just sleeve the cable in PVC and re-seal cleanly.