David A Bosworth Co Inc

Concrete flatwork covers everything flat and horizontal: garage and shop slabs, patios, sidewalks, equipment pads and aprons. Most of what determines whether a slab lasts happens before the truck arrives. The subgrade is compacted, a gravel base of about four inches is placed and compacted, forms are set to grade with slope away from the building, and reinforcement, typically wire mesh or #3 or #4 rebar on chairs, is placed. Residential slabs are usually four inches thick and poured at 3,000 to 4,000 psi; anything that will see trucks or equipment goes to five or six inches. Control joints are cut at intervals of roughly two to three times the slab thickness in feet, so about every eight to twelve feet on a four-inch slab, because concrete will crack somewhere and joints tell it where. Concrete needs about seven days before foot traffic and twenty-eight to reach design strength.

Excavation contractors dig and move earth for foundations, basements, utilities, pools and site cuts. Most residential jobs run on a mini or mid-size excavator paired with a skid steer and a dump truck; larger cuts bring in a dozer or scraper. The price depends less on the size of the hole than on what is in the ground: clay, ledge rock, high groundwater and buried utilities all slow the machine down and change the hauling math. Before the bucket touches dirt the site needs an 811 utility locate, and any trench deeper than five feet needs a protective system under OSHA rules.

Foundation contractors build the part of the structure that carries everything above it into the ground: spread footings below frost depth, stem walls or basement walls, monolithic and slab-on-grade foundations, and pier or grade beam systems where soils are poor. The work follows the stamped plans and the geotechnical report, and it is inspected at fixed points, usually the open footing trench with rebar in place before the pour, then again before the slab and before backfill. Frost depth sets the footing bottom, from about twelve inches in the Gulf states to four feet or more across the northern tier. Waterproofing or dampproofing, a footing drain and free-draining backfill are what keep a basement dry, and they are cheapest to do right while the wall is still exposed.

Hauling contractors move bulk material to and from job sites: delivering gravel, sand, topsoil and fill, and removing excavated spoil, concrete and demolition debris. Pricing is built around truck size and cycle time. A tandem dump truck carries roughly 10 to 14 cubic yards, a tri-axle 15 to 18, and a belly dump or end dump trailer over 20; the driver's rate covers loading, travel, dumping and any wait time at either end. Distance to the pit or landfill is often the biggest variable, and tipping fees for debris are usually passed through separately. Contractors who also run a loader or excavator can load their own trucks, which matters when nothing on site is available to fill them.

Paving preparation is the earthwork under asphalt or concrete: cutting the subgrade to plan, undercutting and replacing soft spots, placing and compacting aggregate base in lifts, and proof rolling with a loaded truck to find anything that pumps before the paving crew shows up. Asphalt is only as good as what is under it, and most premature cracking and rutting traces back to a thin or poorly compacted base rather than the mix. Base thickness runs from about four to six inches of crushed stone under a residential driveway to eight to twelve inches or more under a commercial lot or a road, compacted to 95 percent or better of maximum density, with the surface held to within a fraction of an inch of grade so the asphalt lift is uniform. Prep contractors often also handle the curb subgrade, drainage structures and the connection to existing pavement.

Site preparation is the package of work that turns a lot into a place a builder can start. On a typical job that means clearing vegetation, stripping and stockpiling topsoil, cutting or filling to the pad elevation, compacting fill in lifts, cutting in a temporary driveway, and installing the silt fence and gravel entrance the stormwater inspector expects to see. The scope shifts with the ground: a flat suburban infill lot may take two days, while a sloped wooded parcel with poor soil can run weeks and involve undercutting and replacing unsuitable material. Site prep contractors typically coordinate with the surveyor who sets the corners and the geotechnical engineer who signs off on compaction.

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.