DIPLOMAT DEMOLITION

Demolition contractors take down houses, garages, commercial buildings and foundations, then sort and haul what is left. The teardown itself is the fast part; most of the schedule is the paperwork that has to happen first. Gas, electric and water are disconnected and capped at the main, an asbestos survey is completed by a licensed inspector and any friable material is abated before the excavator swings, and the demolition permit is posted. A residential house typically comes down in one to two days with a 30 to 40 ton excavator; hauling and backfilling the hole can take a few more. Selective demolition, such as removing a wing or gutting an interior for a remodel, is priced by labor hours because it is done with hand tools and small machines around what stays.

Trenching and underground utility contractors open the ground for pipe and conduit, bed and backfill it, and put the surface back. What looks like a straight line on a plan is governed by a few hard numbers: 811 locates before any digging, a minimum cover depth that varies by utility (commonly 18 to 24 inches for electric and gas service, and below the frost line for water), and OSHA's requirement that any trench five feet or deeper have a protective system such as a trench box, shoring or a sloped wall, with a competent person on site. Bedding material under the pipe, compaction of the backfill in lifts and tracer wire on non-metallic pipe are the details that separate a line that lasts fifty years from one that settles and cracks the driveway above it.

Concrete cutting and removal contractors saw, drill, break and haul concrete on everything from a cracked patio to a doorway through a foundation wall. The tools are specialized: walk-behind slab saws with diamond blades for flat cuts, track-mounted wall saws for straight openings, core drills for round penetrations for pipe and conduit, and hydraulic breakers or robotic demolition machines for bulk removal. Wet cutting controls silica dust, which OSHA regulates tightly, but produces slurry that has to be contained and disposed of rather than washed into a storm drain. Because a saw cannot see rebar, post-tension cables, conduit or radiant tubing inside the slab, a GPR scan before cutting is standard practice on any structural or unknown concrete, and cutting a post-tension slab without one can be dangerous.