Facebook Pixel

What Is Horizontal Directional Drilling? How Does It Work?

Modern technology has enabled homeowners to enjoy the convenience of avoiding trenches for their underground drains and sewer repairs.

Pipe relining is the trenchless solution for repairing minor leaks and root intrusions. On the other hand, pipe bursting is more suitable for severely displaced and crushed pipelines.

But how about homeowners who want to add a new pipe to their drainage system? That is where horizontal directional drilling comes in.

Drain Magic is the number 1 partner of South Central Pennsylvania homeowners looking for horizontal directional drilling services. Horizontal drilling is another trenchless technology to add underground pipes without disrupting aboveground elements and structures. If you need our assistance, don’t hesitate to book an appointment.

If you want to learn more about horizontal underground drilling, buckle up! This article will dive deeply into what it is and how it works.

What is Horizontal Directional DrillingWhat is Horizontal Directional Drilling?

Horizontal direction drilling, or HDD, is a trenchless plumbing solution for installing underground utilities. It is hardly a new technology because it’s been the go-to method for industrial and commercial projects. It was only recently introduced to residential properties due to the impracticality of traditional sewer and underground drain installations.

Even with pipe relining and pipe bursting, the known methods for installing new pipes still call for digging trenches. Unfortunately, this archaic process only ruins aboveground structures, hardscapes and landscapes— making it a dreadful option for homeowners.

Enter: horizontal directional drilling.

HDD is best and most economical for installing pipes under the following conditions:

  • Highways and busy roads, which may cause traffic interruptions
  • Beautifully furnished lawns, rose bushes, and landscapes
  • Fully constructed hardscapes and pavements
  • Beneath rivers, lakes or manmade bodies of water
  • Normally impenetrable bedrocks

Consider HDD if you’re dealing with any of the following but need new pipelines for your underground drainage system.

But how exactly does it work?

How Does Horizontal Directional Drilling Work?

Horizontal directional drilling is used for industrial purposes for one reason: it requires heavy equipment. After all, boring an underground tunnel for long distances through soil and rock requires powerful machinery.

But since residential HDD is less intensive, the horizontal underground boring machine is only the size of a golf cart. In general, horizontal drilling follows three basic processes, and we’ll explore them in detail below.

Three-stage process of HDD:

Pilot holeStage 1: Pilot hole

While absent of trenching, minimal digging is required to facilitate the HDD process. The first stage is drilling a pilot hole, serving as the entry point for the drill pipe and drill bit. A high-pressure jet is pumped through the drill pipe to grind the soil ahead.

Professionals are trained and equipped to monitor the drilling process using a walkover guidance system. A transmitter from the drill head informs the tech of the drill’s current coordinates, depth, alignment and slope. This ensures that the drill pipe travels the set route.

Should there be any errors, the operator may manually control the drill to keep it within the predetermined bore path. Of course, existing soil conditions, obstructions and distance will affect the pilot hole’s completion.

Stage 2: Pre-reaming

Upon reaching the exit point, the drill bit will be detached and replaced with a reamer. A reamer is a cone-shaped tool used to enlarge the pilot hole to allow the entry of the new pipe.

The reamer attached to the drill pipe is pulled back and rotated to enlarge the hole. Bentonite, a type of clay soil, is then applied to the borehole to create stability and prevent erosion. Moreover, the drill pipe will release drilling fluid to prevent blockages in the borehole.

Sometimes, multiple pre-reaming passes are required to ensure zero obstructions and the safe installation of pipes. But this is rare in residential settings.

Pipe pullback

Stage 3: Pipe pullback

The last step in horizontal directional drilling is the pipe pullback. In this step, the drill pipe and reamer used in pre-reaming must return to the exit point. To accomplish this, technicians attach a swivel to prevent the new pipe from getting damaged during installation. Drilling fluid is still pumped throughout the process to lubricate the pipe.

The process ends when the drill pipe reaches the horizontal underground boring machine.

Horizontal directional drilling is far from a simple plumbing solution. If you need a new pipe added to your drainage system, HDD is the least invasive and disruptive solution. Our certified Drain Magicians will ensure the process goes smoothly.

For South Central Pennsylvania homeowners looking for HDD services, Drain Magic can help.

Call us at 717-936-9444 or book an appointment here.