How to Lay Pipes Under a Sidewalk

Sprinkler systems frequently require the installation of pipes under sidewalks.

The installation or service of residential electrical conduits, gas lines and irrigation supply lines frequently requires excavation underneath sidewalks and other paved areas. Although this can be accomplished easily with heavy equipment, such measures are often impractical in residential settings or in instances where the scope of the job doesn't warrant an expensive rental. Homeowners without access to specialized digging equipment can excavate pipe trenches underneath sidewalks using either hand-drilling or water-excavation techniques. Hand-drilling offers quicker results but is more labor-intensive.

Things You'll Need

• Hose and adapter
• Shovel
• Gloves
• Safety goggles
• Pipes
• Hammer

Instructions

Hand-Drilling

1. Choose a metal or PVC pipe wide enough to create a trench of sufficient diameter for the pipe being installed. Most projects require a tunnel slightly wider than the diameter of the pipe being installed.

2. Dig a trench deep enough to insert the end of the pipe slightly underneath the surface of the sidewalk. Dig an identical trench on the opposite side.

3. Select a hammer heavy enough to drive the pipe into the soil.

4. Use a series of sharp blows to the pipe's to drive it under the sidewalk.

5. Retract the pipe at regular intervals to remove accumulated dirt and observe the length of the trench.

6. Drive the pipe under the sidewalk with repeated hammer blows until it emerges on the other side.

7. Insert the pipe or conduit into the cavity excavated by the drill pipe.

Water-Pressure Excavation

1. Select a length of metal or PVC pipe long enough to span the width of the sidewalk.

2. Secure a properly sized, threaded hose adapter to the pipe. These are commonly available at garden centers and hardware stores, and the exact size will vary according to the pipe and hose being used.

3. Fasten a garden hose to the house adapter on the excavation pipe.

4. Excavate a small trench where the pipe will enter the sidewalk and another on the opposite side where it will emerge.

5. Put on safety goggles and gloves and turn on the water source.

6. Insert the pipe into the trench under the sidewalk, push it forward and move it back and forth. Let the pressure of the water tunnel through the soil, and continue until water is visible on the other side of the sidewalk.

7. Insert the pipe or conduit into the recently excavated tunnel, once the water and mud have settled.

Tips & Warnings

• Use a saw to cut the tip of the drill pipe at an acute angle, for more efficient soil penetration.

• Contact local utilities and determine the location of buried gas, water or electric lines before digging.

References

• "Scotts Sprinklers & Watering Systems"; Michael McKinley
• Palo Alto Online; Installing Sprinklers: How to Get Under the Sidewalk
• Ask the Builder: Tunneling Under Sidewalks and Driveways