Lystad Construction

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.

Driveway contractors build the surface between the road and the house, from a gravel farm lane to a poured concrete approach, and the base under the surface decides how long any of them last. A typical driveway is excavated to remove topsoil, graded with a crown or cross slope so water runs off, and built up with four to eight inches of compacted crushed stone before the top layer goes on. Where the driveway crosses a roadside ditch it needs a culvert sized by the county, and the connection to a public road is regulated by the road authority. Gravel is the least expensive and needs regrading every year or two; asphalt costs more and needs sealing; concrete costs the most up front and lasts longest if the base and joints are done right.

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.

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.

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.