Concrete Slabs and Pads in Norfolk, VA

What gets poured as a slab

Residential slabs cover shed and outbuilding floors, garage floors, grill and fire pit pads, hot tub pads, air conditioner and generator pads, and small bases for equipment. Commercial slab work covers building pads, dumpster pads, equipment and machine bases, and interior floor slabs where a project calls for one. For larger packages, the commercial concrete page covers how bids are sent.

The size range is wide and the principles hold across it. What changes is thickness, reinforcement and how much base the slab needs, and all three come from what will sit on the slab and how it is loaded.

A pad carrying a concentrated load is a different problem from a floor carrying a spread load. A generator or a hot tub puts a lot of weight in a small area, and it often has to stay level for something bolted or plumbed to it, so it is built for that load rather than matched to the slab next to it.

Base preparation

A slab on grade is only as good as what it sits on: excavation to depth, removal of soft or unsuitable material, and a base placed and compacted to the depth the job needs. The NRMCA guide to cracking calls for removing topsoil and soft spots and compacting the soil or granular fill under the slab. This work decides how a slab performs years later, and it cannot be seen in a finished slab or in a written quote.

Ground conditions add to that. The USGS reports that the southern Chesapeake Bay region has the highest rates of sea level rise on the Atlantic Coast and that land subsidence raises flood risk in low lying areas. A wet or saturated subgrade does not compact the way a dry one does, and a slab placed over it moves.

Where the plans call for a base layer, a separation layer or a vapor barrier under the slab, it goes in as drawn. On an interior floor that detail matters, and skipping it tends to show up later in the floor covering rather than in the concrete.

Thickness, reinforcement and jointing

Thickness and reinforcement come from the loading, and on a commercial job they come off the drawings. Reinforcement only works when it is supported at the right depth. Steel resting on the subgrade does nothing for the slab above it.

Joints are planned to the shape of the pour rather than a default grid. NRMCA joint guidance recommends panels that are square or nearly so and warns against L shaped panels. Cracks like to start at inside corners and around anything that passes through a slab, and the joint layout decides whether one lands in a cut line or across the middle of the floor.

The finish follows what the slab is for. A garage or shop floor is often finished smoother than an exterior pad, while an outdoor pad usually gets a broom texture for grip in the rain.

Footings and thickened edges

A slab that carries a structure usually needs more than a uniform thickness at its edge. That can be a thickened edge formed as part of the slab, or a separate footing poured before the slab, depending on the drawings and what is going on top.

Footings and stem walls are offered alongside flatwork. The work involves digging to firm bearing, forming to the dimensions on the drawings, placing reinforcement as detailed, and sequencing the pours so the slab that follows is not left waiting.

Weather and curing

Pour day depends on the weather. In the cold, NRMCA notes that concrete sets and gains strength more slowly and that fresh concrete has to be protected from freezing. In heat it sets faster. Either way the slab needs curing afterward, and the NRMCA curing guide says that typically runs 3 to 7 days.

Many slabs sit next to other work: a driveway leading to a garage pad, or a patio beside a hot tub pad. Planning them together keeps elevations and drainage in step. Slab work is based in Norfolk and taken across the Hampton Roads service area.