In the commercial construction game, the fastest way to lose your profit margin is rework. I’ve seen contractors try to cut corners during the dirt phase, reasoning that the concrete slab or the asphalt parking lot will "bridge" any soft spots. This is a fatal economic miscalculation. The strength of the finish is entirely dependent on the strength of the grade beneath it. This is why investing the time to use a high operating efficiency impact rammer properly is essentially an insurance policy against future liability.
Let’s say a crew is backfilling a deep sewer lateral that runs underneath a future concrete driveway. If they dump all the dirt in at once and just run a plate compactor over the top, the top 100 mm will look great, but the meter of dirt below it remains loose. Six months later, the loose dirt settles. The concrete driveway loses its support, cracks, and caves in. Now, the contractor has to pay a crew to saw-cut the concrete, demolish it, excavate the soft dirt, re-compact it properly in lifts, and pour new concrete. A process that would have taken two hours with a jumping jack initially now costs thousands of dollars in labor, materials, and destroyed reputation.
On serious commercial sites, we don't just guess if the ground is hard enough. Geotechnical engineers come in with nuclear density gauges or perform sand-cone tests to scientifically prove that the soil has reached 95% or 98% of its maximum dry density. A well-maintained jumping jack operated by a professional is the only tool that can consistently hit those passing numbers in confined trenches. You pay for the time to compact it right today, or you pay tenfold to fix the disaster tomorrow.
