Sharp's Excavating

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.

Decorative concrete is standard flatwork with a finish applied while it is wet or after it cures: stamped patterns that mimic stone, slate or wood plank, integral or broadcast color, acid or water-based stains, exposed aggregate, and polymer overlays that resurface an existing slab. The finish adds a lot of labor in a short window. On a stamped pour the crew has to place, color, stamp and detail the whole slab before it sets, so crew size and weather matter more than on plain concrete. Because the surface is the product, the base, thickness, reinforcement and joint layout still have to be right, and joints should be planned into the pattern rather than cut across it afterward. Sealer is what keeps color and finish looking new; most decorative surfaces need resealing every two to three years, and stamped surfaces can be slippery when wet unless a grit additive is used.

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.

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.

Retaining walls hold back soil where a grade change is too steep to slope, and they fail for one reason far more than any other: water. A wall that lasts has a compacted crushed-stone base, a perforated drain pipe at the heel, clean gravel backfill behind the wall face, and geogrid layers tied into the backfill on anything tall. Segmental concrete block is the most common residential system and can be built by a landscape contractor up to about four feet; above that, or wherever a driveway, slope or structure sits above the wall, an engineer's design is required by most codes and the wall becomes structural work. Poured concrete and reinforced masonry walls are used for tall cuts and tight sites, boulder walls for rural and natural-look projects, and pressure-treated timber for budget walls with a shorter life.