You can never really know what your true replacement costs will be once you make the decision to open cut a yard or driveway. You will be the point man for any problems that arise with the restoration of the landscaping or concrete repair. Callbacks are costly and will quickly chip away at your profit margin. Can you afford to take that risk?

“Many contractors open cut because they don’t know any different,” says Carla Miller, of PortaMole Boring Systems, Ft. Worth, Texas. “They’ve been doing it that way forever. They believe that the only boring equipment available to them is out of their price range. It’s just a lack of knowledge.”

Once you decide to bore for those irrigation pipes, there are several boring systems at your disposal. Knowing what they are and how they work will help you choose the right system for the job before you.

The most basic way to bore for irrigation pipes under pavement is by jetting and hammering. That involves attaching a water hose to PVC pipe, and inserting it into a pilot hole. The idea is to have the water pressure rinse enough soil away so that you can hammer the length of PVC pipe that needs to go under the driveway. A combination of water and brute force are utilized to bore the hole. If the pavement you’re boring under is a sidewalk three or four feet wide, this works. But if you’re trying to span a 20-foot-wide driveway or more, it will take you some time to accomplish the task. You may want to explore other options.

Photo courtesy: HammerHead

One of those options is a ground piercing tool. Steve LaFontaine of Bullet Mole, in Chino, California, says their tool provides an affordable way to bore under pavement. Using either a sledgehammer or a jackhammer to drive the tool, you place it at an entrance trench typically 5-6 feet long. LaFontaine says its hardened steel tip is capable of piercing rock and can bore under a six-foot driveway in a matter of minutes.

“The concept is that all you’re driving through the ground is the point,” says LaFontaine. “You’re not driving the shaft, which is skinnier than the point. The friction doesn’t increase as the tool advances. It’s a one-man operation” Available in either a two or four foot length, additional extension shafts can be added to the piercing tool, allowing it to bore a two-inch diameter hole a distance of approximately 60 feet.

Another option is a boring attachment that’s used with a hand drill. There are several manufacturers of these products. Using an electric, gasoline, or pneumatic drill with a 1/2”, 5/8” or 3/4” chuck, you attach a drill bit to one end of a threaded galvanized pipe. The other end of the pipe goes into the boring atachment, which in turn, goes into the drill chuck. A garden hose is connected to a ball valve on the attachment. The water is used to help flush the shavings and lubricate the drill bit.

Before boring, you dig a ditch slightly deeper than the starting point of the bore hole, and long enough to hold the drill pipe and drill. Depending on drilling conditions, pipe from three to ten feet can be used. Boring at speeds of 350 to 450 rpm, you can add drill pipe as needed to a maximum length of 70 feet. When you’ve tunneled through, attach whatever you are installing to the end of the drill pipe. As you withdraw the pipe, you pull the desired material back through the hole.

For someone not familiar with boring through dirt, this is an inexpensive way to get your feet wet (and your hands a little dirty). For the contractor reluctant to give up hammering and jetting because he believes it’s the cheapest way to go, think again. Wes Breecher of Borit Manufacturing, Phoenix, Arizona, says that when you factor in labor costs and the time it takes to do the job, the small investment you make in the equipment will pay for itself with one job.

“It will save the guy hammering and jetting money,” says Breecher. “He can do the job in about 20 minutes instead of an hour. And it’s a lot less messy because when they’re pounding the PVC underneath the driveway, they’re using water pressure to wash away the dirt, where our system uses just enough water to soften the soil. And it compact bores the dirt underneath the driveway rather than back boring. The only thing they have to clean up is to cover the trench back up.”

The affordability of these attachments makes them ideal candidates for entering into the world of pipe boring. These tools are easy to use, easy to repair and maintain, and easy to transport. Breecher says his company’s product can accurately bore a 4 ¾” diameter hole for a length of 70 to 80 feet. The company is currently testing new drill bits that will increase the diameter of the bore to six inches.

If the job requires a longer bore, the next step can include a technology that has been around for years. Pneumatic boring tools (commonly known as moles and/or torpedoes) are increasingly being used to punch a hole under landscape and pavement. Powered by air compressors, these small-diameter boring tools minimize excavation and will do the job at a cost considerably less than trenching and open cutting.

Photo courtesy: Mini-Mole An example of installing an irrigation line under a driveway.

They are ideal in situations where there’s little room to accommodate even the smallest ditch. All they require is a suitable entry and exit pit on either side of the surface you’re boring under. Aiming sights help you guide the tool toward the desired target. Once you launch the tool, a pneumatically driven piston, hammering on the nose of the barrel, steadily drives the tool forward through the soil.

The production rate of the tool averages one to two feet per minute, depending on soil conditions. It can usually bore under a 20-foot driveway in 20 minutes or less. Once the tool emerges at the exit pit, simply disconnect the air hose, attach the new pipe to the air hose with an adapter, and pull it back under the driveway.

The sizes of these piercing tools vary, as does their length and weight. But for the needs of a landscape contractor, a two-inch diameter tool will handle most jobs. It typically weighs about 25 pounds and is three-feet long. In contrast, a four-inch diameter tool can be five feet in length and weigh over a hundred pounds. The range of the bore of these tools is generally 50 to 100 feet. Their accuracy is affected by soil conditions and the depth of the bore. As a general rule, the deeper the bore, the more accurately these piercing tools work.

Pneumatic piercing tools are ideal when the boring depth is beyond the range of other boring systems. Their use gives the landscape contractor additional flexibility in taking on jobs that he might have once turned down. “It’s not a matter of what’s better,” says Jason Haas, of HammerHead, in Oconomowoc, Wisconsin, “it’s a matter of having an additional tool at your disposal. What it comes down to is that every contractor has several tools in his arsenal. You just have to pick the right one for the job.”

If you’re installing pipe beyond the range of the tools we’ve discussed, then a machine capable of long-distance ground-level rotary boring is the next option. Images of huge industrial machines come to mind, but there are smaller systems that can bore hundreds of feet. Often, the landscape contractor rents these machines, but they are more affordable than you might think. And their durability makes them a wise investment for anyone serious about the business of installing irrigation systems.

“We use the same technique they use in the search for oil and gas,” says Miller, “except we do it horizontally. We use engines with a six to one gear reduction, so they rotate the drill stem very fast. That’s the key to accuracy. There’s a law of physics called the conservation of angular momentum. Simply stated, it means the faster you rotate the drill stem, the more it takes to divert it from its intended path. Typically, slow boring equipment is not very accurate.”

Miller describes her company’s PortaMole as “a lawn mower on steroids.” Using a gas-powered engine and galvanized pipe as a drill stem, the 2-wheeled machine sits on the ground. Its drill stem and bit flex down into a narrow trench that’s dug to the depth of the bore you need to make. If there’s room, you can use a drill stem equivalent to the total length of the bore. If space is tight, sections of the drill stem can be added as needed.

Photo courtesy: Porta-Mole One contractor commented, "I want one just kept on my truck."

During the boring process, a hand winch attached to the machine is used to propel it forward. “We think that’s very important, says Miller. “It gives you operator sensitivity; the operator is very aware of what the drill bit is encountering. When you hit rock, you will know.” Miller says her company’s machine will bore through rock.

The 5hp model can bore a six-inch diameter hole the length of 100 feet and weighs just under 100 pounds; the 9hp model can bore a 13-inch diameter hole for a distance of 200 feet and weighs 120 pounds. The company’s newest product, the Mini-Mole, is a smaller variation of its bigger brothers, weighing just 35 pounds, and is capable of boring a four-inch-diameter hole a distance of 40 feet.

In terms of safety, workers using these types of ground-level boring machines are not placed in the potentially dangerous situation of having to work in a pit. And with no pits to shore up, time and money are also saved. These machines will also make you money by giving you more autonomy to bid on jobs you might not have attempted before. “This equipment is priced in such a range,” says Miller, “that contractors can bid very competitively. They don’t have an overpriced piece of equipment to factor into the bid. In many instances, we’ve had contractors who paid for this equipment in the first few jobs.”

There’s also a piece of equipment you may already own that can be used to bore underground. Companies like Ditch Witch make boring attachments for their trenchers. These attachments are typically used for pipe installation projects under driveways, neighborhood streets, and sidewalks. The initial bore is made with a 1 ¾” diameter bit. Then a backreamer is placed on the drill string, with the pipe attached to enlarge and install pipe in the ground all in one pass.

And when the length of the bore needs to be 300 feet or more, Ditch Witch and Vermeer are among the companies that make large horizontal directional machines that can bore that far. If you’re installing pipe or cable hundreds of feet under a lake, railroad track or creek bed, you can’t beat a directional machine. But in all likelihood, you’re probably not going to need a 9,000 pound, 470 horsepower piece of machinery to install an irrigation system.

According to Miller, 90% of all the horizontal holes bored in the world are under 6 inches in diameter, and under 40 feet in length. The amount of boring required to install an irrigation system easily falls into that category. And those numbers are also within the capabilities of the boring equipment that’s both available and affordable for the landscape and irrigation contractor.

So put away those concrete saws. Stop open cutting pavement and driveways. You have better, wiser, more cost-effective options before you. Leave the property you’re working on in the same condition that you found it. Make your mother proud.

              hen you were a kid, your mother probably told you to leave things the way you found them. You probably ignored her. But in the world of the landscape contractor, you couldn’t find better advice. When installing an irrigation system, the goal is to look like you’ve never been there. Using a boring tool to install those irrigation pipes will help you achieve that goal.

In many instances, it’s difficult to avoid trenching. And there will be times when trenching dirt to accommodate irrigation pipes, especially before laying down seed or sod, makes perfect sense. Where landscape contractors get themselves into trouble is when they begin tearing up perfectly good lawns, asphalt and concrete when the right boring tool could have done the job.

We’ve all seen the end result: a one-foot wide by 20-foot long hunk of driveway is cut out when it comes between an irrigation system and a water source. Part of the problem is that some landscape contractors see cutting and trenching as the cheapest and quickest way to get the job done. Several factors lead them to that erroneous conclusion. First and foremost, it’s just the way they’ve been doing it for years, and old habits truly die hard.

Price is another stumbling block. Prioritizing what equipment to buy is always a constant struggle. And boring equipment can seem like a luxury, when you can rent what you need to cut and dig through pavement. But there are costs you may not be factoring in, regardless of whether you do the job yourself or sub-contract the cutting and repair work to someone else.