Flatwork is the trade's word for any concrete poured flat on the ground: the slab under a new shed, the floor of a detached garage, a half-court in the backyard, a pad beside the driveway for the boat. Concrete flatwork in Plainfield, IL is simple to pour and easy to get wrong, because most of what decides whether a slab lasts happens before the truck arrives: where it sits on the lot, what is under it, and which way the water runs off it.
We pour garage slabs, shed pads, sport courts, RV and trailer pads, hot tub pads and the small utility slabs for air conditioners and trash cans. In Plainfield, where each of those can go is set by village rules, so each section below starts there.
Garage Floor Slabs for New and Detached Garages
A garage floor is the hardest-working slab on the property after the driveway. Plainfield's flatwork packet sets a floor of 4 inches of concrete over 4 inches of compacted gravel, with a vapor barrier and welded wire reinforcing, and the slab is inspected before the pour. An attached garage also needs a curb at least 4 inches high along every wall it shares with the house. The floor gets pitched toward the overhead door so meltwater runs out instead of toward the back wall.
A detached garage has to go in the rear yard or an interior side yard, never in front or on the street side of a corner lot. A lot can have at most two detached accessory buildings, together no larger than 1,000 square feet or the footprint of the house, whichever is smaller, and detached garages and sheds top out at 15 feet tall. Sizing the slab is the first decision on the job, and it has to fit those numbers.
Replacing a cracked or sunken floor in an existing garage is a different job, covered on our garage floor repair page.
Shed Pads and Accessory Slabs
A shed on a concrete pad stays square and dry for decades; a shed on blocks in Plainfield clay tends to rack and let water in. The village caps sheds at 500 square feet and keeps them at least 5 feet from the rear and interior side lot lines, or farther where the easement is wider, and never inside an easement. The shed permit is $50, and when the shed sits on a concrete slab the slab is inspected before the pour.
The rear-yard easement is where most shed plans run into trouble. Village subdivision rules keep a continuous drainage and utility easement along rear lot lines, and nothing that blocks water can go in it. We find that line on your plat of survey before we stake the pad.