An old concrete slab or patio comes out by breaking it into pieces, with a jackhammer on a small pad or a hydraulic breaker on a machine for anything bigger, then loading the pieces and hauling them to a site that takes concrete. How hard that is depends on things you can check first: how thick it is, what steel is cast into it, what runs underneath and how a machine and a truck reach it.
Dig at the edge before anything else
Take a shovel to one corner and dig down beside the slab until you find the bottom. That one hole tells you most of the job. A backyard patio poured thin over a little gravel breaks easily. A garage floor or an old carport slab is often thicker, and many have a thickened edge or a footing along the outside that runs deeper than the middle. Look at the broken corners and cracks too. Thin wire showing in a crack is welded mesh. Thick ribbed bars are rebar, which holds broken pieces together and has to be cut. Some slabs turn out to be two pours, one on top of the other.
What may be running under it
Old slabs hide things. A water line to a hose bib, a power feed to a shed, a gutter drain, a septic line from the house, or a gas line to a grill can all be under the concrete or right beside it. Public lines are marked through 811. NC811 asks for three working days' notice before digging, and SC811 asks for at least three full working days and not more than twelve. Those locates cover public utility lines only. SC811 says plainly that private lines on your side of the meter are the property owner's job to identify, so think about what you ran out to the shed or the garden years ago.
Jackhammer, breaker or sledgehammer
A thin walkway can sometimes be cracked with a sledgehammer and pried up with a bar, a section at a time, once you dig the edge out so the piece has somewhere to drop. Past that, a rented electric jackhammer handles a small patio, slowly. A slab of any size goes far faster with a hydraulic breaker on a mini track loader or an excavator, because the same machine then picks the pieces up. Where part of the concrete stays, such as a walk that meets the patio, cut a clean line with a saw first. Otherwise the break can run into the part you meant to keep.
Silica dust is the hazard people forget
OSHA says breathable crystalline silica dust is created when concrete, brick, block and stone are cut, drilled, ground or crushed. Breathing it can cause silicosis, an incurable lung disease, along with lung cancer, chronic lung disease and kidney disease. That is a real reason not to saw or break concrete dry in a closed garage. OSHA's construction guidance gives applying water to the saw blade as one way to keep the dust down, and the same thinking applies to breaking: wet the work, stand upwind and keep children and pets away. Eye and hearing protection matter as much as gloves. Flying chips travel further than you expect.
Where the broken concrete goes
Broken concrete is heavy, and a pickup or a small trailer reaches its limit long before it looks full. Keep it clean of wood, trash and soil if you can, because many disposal sites handle clean concrete differently from mixed demolition debris. Polk County's solid waste page, for example, lists concrete, blocks, brick and asphalt among the materials handled at its landfill. Greenville County's residential rate sheet puts dense construction material in a category of its own. If you are hiring a roll-off, say up front that concrete is going in, so the load can be planned around weight rather than space. Good flat pieces can also be stacked into a garden wall.
Roots, stumps and an old tree under the patio
A lot of slabs come out because a tree lifted and cracked them. When the concrete is gone you may find thick surface roots and the old stump or root flare right at the edge. If the tree has already been cut, the stump can be ground below grade in the same visit, which leaves a clean spot for the new surface rather than a hump. Stump grinding works around concrete you are keeping as well, with the machine set up so it does not crack the edge. Tree still standing beside the patio? Send a photo and talk through the order of work before the new slab is poured.
What the ground looks like afterwards
Under most slabs is a layer of gravel, sometimes a sheet of plastic, and then packed subsoil that has not seen light in decades. Grass will not do much in it. If lawn is going back, plan on topsoil, raking it to drain away from the house, and seeding or laying sod. If a new slab is going in, the base wants to be graded and compacted for it, which is where new concrete pads and drives start. A shallow hollow left where the thickened edge came out needs filling in layers, not in one dump of loose dirt, or it settles.
Common Questions
How can I tell how thick my concrete patio is?
Dig a hole at one edge with a shovel until you reach the bottom of the slab, then measure. Check more than one side, since many slabs have a thicker edge or a footing along the outside. Look in cracks for wire mesh or rebar while you are there. Those two answers tell a contractor most of what the job will take.
Can broken concrete go in a roll-off dumpster?
Often, but ask first and say how much. Concrete is so heavy that a container fills to its weight limit long before it looks full, and some loads have to be kept clean of other debris. Tell the hauler it is concrete, roughly how large the slab is and whether it has rebar in it.
Do I need to call 811 before breaking up a concrete slab?
If you will be digging, yes. Breaking out the edge, pulling footings or regrading afterwards all count. NC811 asks for three working days' notice and SC811 for at least three full working days. Private lines such as a shed feed or irrigation are not marked, so point those out yourself.
What to Do Next
Have an old slab, pad or patio that has to go? Send photos of the concrete, a broken edge if you have one and the way in, and Jordan will price breaking it out and hauling it, leaving the ground ready for what comes next. Or call (828) 574-4474. What moves the price is covered in demolition cost.
See our demolition service or call (828) 574-4474.