How to Break Concrete

There are times when you need to break up a section of concrete to repair underground pipes or when you're transforming a concrete yard into a garden to create a green space. With a little effort and the proper tools, you can remove an entire slab or just a small portion. After that, all you need to do is load the broken concrete into a truck to transport it to the location for leveling.

Contact utility service companies. Be sure to call local utility companies to ensure there are no electrical wires or pipes under the concrete floor. It's advisable to hire a professional if possible, as digging near gas or electrical lines can be hazardous.

Use safety equipment. Breaking concrete generates harmful dust and sharp debris, so it’s crucial to protect yourself and your colleagues with safety goggles, dust masks or respirators, steel-toed shoes or boots, thick gloves, and heavy-duty clothing covering your arms and legs.

• If you plan to use electric tools like a concrete breaker, consider using earplugs.

Cover the concrete slab with a plastic tarp to protect fragile items. Be cautious when using a tarp, as it can sometimes cause slips or falls. However, it is essential to cover the slab if you're working near delicate objects or structures.

• If you're working in a spacious area away from fragile structures or items, you might not need a tarp.
• Concrete debris can be thrown far due to the force of the hammer and tools. If unsure, you should shield the surrounding area.
• If you don’t use a tarp, plywood can be used to protect nearby windows or fragile items.

Find a large crowbar. Whether you’re using a sledgehammer or a concrete breaker, you’ll often need a crowbar to pry apart broken concrete sections. The demolition process will be faster if one person breaks the concrete while another follows to pry the pieces apart.

Use a sledgehammer to break thin concrete slabs. If the concrete is only about 10 cm thick, use a sledgehammer. Start at the crack, corner, or edge of the slab, as breaking concrete is easiest near the edges.

• Don’t attempt to swing or lift the hammer high above your head; instead, keep the hammer at shoulder height and strike downward onto the slab.
• Use a crowbar to pry the concrete pieces apart after breaking them. Then, move the debris out of the way to avoid tripping hazards.
• If the concrete isn’t cracking after 10 minutes and you're exhausted, switch to a concrete breaker.

Dig beneath the slab if the concrete is too hard. Digging beneath or removing soil under the slab will make it easier to break the concrete. Use a shovel to dig under the edges of the slab, then use a sledgehammer to break the slab’s edges.

• The more soil you remove beneath the slab, the easier it will be to break the concrete. Even removing a small amount of soil will make the concrete more fragile.
• While digging, use a garden hose to moisten the soil and wash it away.

Use a Concrete Breaker. A 27kg concrete breaker is sufficient for most household tasks. Only opt for a heavier pneumatic breaker for extremely thick or hard concrete.

• Always use the chisel tip to break the concrete. The chisel helps focus the force on the concrete, making it easier to break.
• Let the weight of the machine do the work, don’t push down to add extra force. Pressing the chisel can damage the tool or cause it to jam.
• If the concrete doesn’t break immediately, stop the machine and move it a few centimeters to a new spot. Continuing could cause the chisel to get stuck.
• Break the concrete into pieces spaced 5-8 cm apart to minimize the risk of jamming the chisel.
• Use a crowbar to pry out the broken pieces once they’ve cracked.

Dealing with Steel Mesh or Rebar in Concrete. After breaking concrete, you may encounter reinforcing steel bars. Handle these while separating the concrete pieces:

• If the concrete is reinforced with steel mesh or welded steel bars, use bolt cutters to cut the rebar. You can also use wire cutters for cutting mesh steel.
• Rebar that is welded together will be much harder to cut. In this case, use a reciprocating saw or a circular saw to cut the welded rebar.

Use a Pickaxe to Separate Stuck Concrete Pieces. If the concrete pieces remain stuck together, making it difficult to break the surrounding area, start by clearing the broken chunks. Then, you can use a pickaxe to pry apart the stuck pieces:

• Drive the sharp end of the pickaxe into the crack between two concrete slabs and pry them apart.
• Once the crack is wide enough, switch to the flat wide end of the pickaxe to separate them completely.
• If the concrete pieces still won’t budge, try prying from the opposite side of each slab.

Identify the Area of Concrete to Break. If you are trying to locate a broken water pipe and can roughly guess its location, you’ll save a lot of effort and cost. Look for the following clues:

• For pipe issues, try to determine the position and depth of the underground pipe. Look for outdoor drains, sewer pipe openings, or use a pipe locator tool.
• If there’s a leak from the drinking water system, find the area where water seeps through cracks in the concrete floor or seeps along the edges of the concrete slab.
• If the issue involves electrical wiring, you may need to find the insulating conduit running outside the concrete area and dig it up to trace the electrical path.
• For other issues, consult the building plans with your local authorities or request the contractor to provide the building plans of the property.

Mark the Area of Concrete You Plan to Remove. Measure the distance from the edges of the concrete slab to create a clean, parallel hole that will be less noticeable once repaired. Use a pencil or chalk to mark the area.

• Since you don't know what lies beneath the concrete, leave extra space around the area to avoid causing further damage.

Shut off All Relevant Utilities. If you're digging near electrical lines or pipes, make sure to turn off the water and electricity before you begin. You certainly don’t want to risk electrocution, water flooding your home, or a gas leak.

• Call utility companies to locate electrical lines and other hazardous structures before starting any digging project.

Cut Along a Straight Line, As Deep as Possible. First, you'll need to rent a concrete cutter. Make a clean, straight cut to create a neat edge once the concrete slab is removed. If you're searching for a broken pipe, expand the hole after removing the first concrete section.

• Be extremely careful while cutting concrete. Concrete cutters are powerful machines that can cause serious injury or even death if misused.
• Always wear a mask or respirator to protect your lungs from cement dust and follow the tool's instructions carefully.
• If possible, use a cutter with a water hose attachment to reduce airborne dust and prevent the cutting disc from breaking.

Break Concrete Near the Cut. Use a heavy-duty hammer drill or a chisel attached to a rotary hammer to break the concrete close to the line you just cut. Angle the chisel so that the concrete you want to remove will break off, not the concrete you want to keep intact.

Chisel Deeper Gradually. Continue using the same tool to break the surrounding concrete near the cut, gradually chiseling deeper until you reach the bottom of the concrete slab. This step is the most challenging, as the pieces you want to remove won’t break loose until there’s enough space for them to release.

• You might need to leave tougher areas of concrete until the adjacent sections have been broken and released.

Break into the interior to widen the gap. Once you've created a gap between the concrete that needs to be removed and the concrete that needs to stay, continue chiseling with the same tool. The gap should be at least 8 cm wide, or wide enough to remove the concrete pieces.

• Hold the chisel at an angle toward the hole's interior and begin chiseling around its perimeter. This prevents the chisel from digging straight into the hole.
• If you chisel too deep, the chisel may get stuck, making it impossible to remove.
• If the chisel gets stuck, use a new one to break the surrounding concrete and remove the stuck chisel.

Break the concrete using a sledgehammer or a concrete breaker. Once the gap is wide enough to avoid damaging the concrete you want to keep, you can apply the techniques described in this section to remove the entire concrete slab.

• Use a crowbar for the fastest and most effective results.
• Avoid using a concrete breaker or similar power tools if the concrete is near pipes, electrical cables, or gas lines.
• Remove the broken concrete pieces from the hole as they accumulate, making it easier to work and also helping you detect any pipes or electrical wires.
• Use bolt cutters to cut rebar and a circular saw to cut steel bars.

Clean the hole walls. After removing all the concrete, trim the remaining concrete on the hole's walls to create a smoother surface. This ensures better quality for any future repairs (or just makes the edge of the concrete look neater if you don’t plan on patching it up).

Locate the damaged pipes (if applicable). If you're searching for damaged pipes or electrical lines, keep an eye out for signs while breaking the concrete, such as water puddles or traces of moisture. If you find the pipe, continue breaking the concrete along the pipe until you locate the damaged section.

• When approaching the pipe or electrical line, slow down and use the hammer carefully to avoid causing further damage.
• To protect the pipe and electrical wiring, try not to hit the concrete directly above them.
• Avoid using a hammer on cast iron or PVC pipes, as these materials are brittle and can easily break.

Use rubble to fill the hole. If there's a large hole in the yard, you can use rubble to fill it. Cover the pipes or any other objects with soft soil to prevent damage when they come into contact with the returning concrete debris.

Use a large wheelbarrow or trolley. Transport the rubble to a larger container using a big wheelbarrow. Concrete is heavy and can damage smaller wheelbarrows, or you can use a trolley for transport. With a trolley, you only need to move the concrete pieces a few centimeters rather than lifting them into a wheelbarrow.

• Don't overload the wheelbarrow to avoid tipping it over and creating extra work. Transporting smaller loads multiple times will help prevent overloading.
• Consider renting an electric wheelbarrow for easier transport.

Rent a large dumpster from a waste disposal company. If you need to dispose of a significant amount of concrete, it's essential to rent a large dumpster. Many waste disposal companies offer reduced service fees for concrete waste.

• Be sure to ask how much concrete can be placed in the dumpster; otherwise, you may need to remove excess or pay an additional fee for disposal.

Contact landfill sites to inquire about concrete disposal fees. In some areas, only landfills that accept construction materials will take concrete. The disposal fees at these sites can be high, so it's wise to check in advance.

Transport concrete to the landfill. Be cautious, as trucks may not be able to carry as much concrete as you expect. Use a heavy-duty truck and don’t fill the bed to capacity. Loading half the bed is typically fine for large trucks, while for smaller trucks, you should load about a quarter of the bed.

• You can also use a trailer for the truck, but be extra cautious in this case. An overly heavy trailer could hit the truck or cause materials to spill out.
• Some construction material supply companies may accept rubble for free if you call in advance and agree to transport it yourself.

Provide rubble for other construction projects. Concrete fragments can be used to elevate the foundation of a house or other structures. You can also arrange concrete slabs, which resemble road curbing, to create walkways. Paint the slabs in unique shapes to make decorative pieces for your garden.

• Additionally, you can arrange the concrete pieces in a circle to create a fire pit in your backyard.