Garage & Shed Slabs in Sioux Falls, SD

Garage and shed slabs in Sioux Falls carry a lot: vehicles dripping salty slush all winter, snowblowers and mowers, workbenches, tool chests and storage. Whether you are building a detached garage behind an older home, adding a shop on an acreage outside town, or setting a shed in the backyard, the slab is the part that has to be right first. A shed or garage can be replaced or reframed; a slab that cracks, settles or holds water stays a problem as long as the building stands.

Sizing and thickness

Start with the building plans. The slab has to match the building's footprint and, for garages, tie in with the footings or thickened edges the design calls for. HomeGuide lists a two-car garage floor at about 400 to 576 square feet and a shed foundation at about 100 to 400 square feet. A 4-inch slab is common for sheds and light-use garages. Heavier vehicles, car lifts, trailers or equipment call for 5 or 6 inches and more reinforcement. Tell us what will live in the building and we will size the slab for it.

Base, vapor barrier and reinforcement

We strip topsoil, compact the subgrade, and place and compact a gravel base. Inside a garage or heated shop, a vapor barrier under the slab helps keep ground moisture from coming up through the floor. Reinforcement, rebar or welded wire, is set on supports so it ends up in the middle of the slab instead of lying in the gravel. Where the building has anchor bolts or hold-downs, we set them in the fresh concrete to the framer's layout.

Slope and the door apron

A garage floor should fall slightly toward the overhead door so meltwater from cars runs out instead of pooling against the back wall. The apron outside the door takes the most wear and salt, so we pay close attention to its base and joints. For a shop with a floor drain, the slab is pitched to the drain instead. A shed slab should sit a little above the surrounding grade so rain does not run under the walls.

Timing with the build

Slabs for new buildings are usually poured before framing. If the building is already on order, we coordinate so the slab has time to cure before the walls go up. For a garage floor replacement inside an existing building, the old floor is broken out and hauled through the door, which takes planning around the framing. We also check whether your project needs a building permit before scheduling.

Caring for a garage floor

Clean salt and slush off the floor through the winter and rinse it in spring. Seal the floor once it has cured, or plan for a floor coating if you want an easy-clean finish. Keep heavy jacks and stands on plywood pads. Fill joints and cracks so water cannot get under the slab and freeze.