While interior demolition is a niche, it is also an area of opportunity. “It is growing very rapidly,” says Kendall Aldridge, national sales manager, IHI Compact Excavator Sales. Many buildings, such as hospitals and grocery stores, need to be repaired and brought up to code. “Contractors have realized there are tools that speed up the process, which allows them to bid more work and be more efficient.”
Among them is Donley Concrete Cutting Co., Pickerington, OH, which uses IHI 9VX electric mini-excavators for concrete removal and excavation in interior applications. “Our business is cutting and drilling concrete,” says Dave Donley.
The company performs work in basements preparing trenches for utility installations. “We remove the concrete with the mini-excavator. Then we put an 8- or 12-in.-wide bucket on the excavator and dig a trench so a contractor can run the electrical or plumbing,” Donley explains. “The excavator replaces four or five guys digging with a shovel.” Because it is a specialty tool, the utilization rate will vary. “It does not go out every day, but when you need it, you need it.”
The single-phase 208- or 220-volt and three-phase 480-volt electric units offer an advantage over diesel. “We do a lot in hospitals and other buildings where you just can’t have any fumes,” says Donley. “It is a machine that we definitely value.”
The units also provide ready accessibility. “The tracks on this machine will move in (retract) to go through a regular door,” notes Donley.
Find the right fit
Once inside a building, mini-excavators offer much higher productivity compared to a hand-held tool, and reduce operator fatigue.
“If a job needs more demolition than one person can handle in a day, it is worth bringing in an excavator with a hydraulic breaker,” says Marcus Auerbach, director of compact equipment, Wacker Neuson Corp. “A mini-excavator is really the best carrier for a breaker. It is much better suited than a skid steer because it allows positioning the tool in many different angles and can complete jobs on walls and structures, while a skid steer can only break up concrete on the floor.”
Gaining access to the building is often the highest hurdle. “If it’s a garage door, you can get a larger (wider) machine in. But if it’s a smaller door, that limits your choices to something that retracts to about 32 in. wide,” says Greg Rostberg, marketing manager, Bobcat Co. “Many machines have strict height criteria limitations, and that’s typically around 8 ft. [for getting under a garage door]. Gaining access is always the biggest restriction. Once you are inside, you just have to maneuver the machine.”
Demolition robots fit into tight spaces, as well. “Each of Husqvarna’s three DXR demolition robots is 31 in. wide, so they fit through most standard doorways,” says Johan Ekstrm, product manager, Husqvarna. “When in use, the machines’ track extends from under the body for stability and individually controlled outriggers (available on most models) allow the machines to be sturdy on uneven surfaces and when close to walls.”
Machine weight and dimensions are extremely important when planning demolition jobs. “The floor in a building could be deteriorating and therefore unsafe,” says Ekstrm. “Knowing the weight of the machine enables contractors to know whether or not it will safely operate on a particular surface. Knowing the dimensions enables contractors to ensure the unit will be able to fit through doorways and make it up stairs and elevators, as well as other areas in the building.”
Also consider the tailswing of the machine. “Many times, getting through the door is the main issue. Conventional tailswings are typically narrower and best for that,” says Rostberg. “Once you’re there and operating, if you are concerned about hitting other objects, a zero tailswing machine would be best. A retractable undercarriage provides the best of both worlds.