Cracked Concrete Repair NJ: Causes & Lasting Solutions

Discover what causes common cracks and how to fix the root issue for good.

Do you have cracks in your concrete driveway, patio, or sidewalk?

Cracks are more than just ugly lines. They can mean bigger problems are hiding underneath, and they often get worse over time, especially with our state’s changing weather.

For homeowners, it’s smart to know why concrete cracks and how to find a lasting fix for your property.

Concrete, known for its durability and strength, is a widely used construction material. Over time, concrete slabs may develop cracks in driveways and sidewalks due to shrinkage, settlement, traffic, or harsh weather.

This article will explore the causes and types of concrete cracks and discuss practical concrete repair methods for preventing further damage.

Please note: This guide helps you understand concrete cracks and different ways to fix them. Concrete Chiropractor does not directly patch or seal cracks. Instead, we fix the real problems underneath that cause many serious cracks, like when concrete sinks. We do this using professional concrete leveling. Our goal is to give you helpful information.

What Makes Concrete Crack?

Concrete cracks for several reasons. Knowing why your concrete is cracking helps you understand what kind of fix might be needed.

Soil Settlement and Erosion:

This is a major factor in New Jersey. When water from heavy rains or melting snow seeps into cracks or through joints in your concrete, it can wash away the soil or dirt beneath.

This creates empty spaces, or “voids,” below the slab. Without solid support, the concrete then sinks into these voids, causing it to crack.

Our state has many different soil types, from sandy areas near the Shore towns that can shift easily, to clay-rich soils in places like Princeton that can expand and shrink with moisture changes.

These varied soil types can also lead to uneven settling over time.

Thermal Expansion and Contraction:

Just like many materials, concrete expands when it’s hot and shrinks when it’s cold. New Jersey’s climate has harsh seasonal changes, with freezing winters and hot, humid summers.

This constant expanding and shrinking puts immense stress on concrete slabs. If the concrete isn’t properly designed with “control joints” (deliberate cuts that let the concrete expand and contract safely) or if these joints aren’t spaced correctly, this stress will lead to cracks.

Drying Shrinkage:

When concrete is first poured, it contains a lot of water. As this water evaporates during the drying process, the concrete naturally shrinks a little bit.

This shrinkage can cause small, hairline cracks to form. These are often normal, especially if they follow control joints, but they can worsen if other problems develop.

Heavy Loads:

While concrete sidewalks and driveways are built to be strong, they have limits.

Consistent heavy traffic from delivery trucks, garbage trucks, utility vehicles, or even cars illegally parked on the sidewalk can put too much stress on the concrete and the soil underneath.

This repeated pressure can weaken the ground’s support and eventually lead to cracking and sinking.

Poor Subgrade Preparation:

Before any concrete is poured, the ground (or “subgrade”) beneath it must be properly leveled and packed down tightly.

If the soil isn’t compacted well enough, it can leave air pockets or loose areas. Over time, this loose soil can settle or wash away, causing the concrete above it to shift, tilt, and crack.

This issue might not show up right away, but it can appear months or even years later.

Types of Concrete Cracks and What They Mean

Concrete cracks come in different forms, and each type can tell you something about what’s going on with your concrete and what kind of attention it needs.

Hairline Cracks / Crazing:

These are very fine, shallow cracks that often look like a spiderweb pattern on the surface.

They usually happen when the very top layer of concrete dries too quickly. They are mostly cosmetic and don’t typically mean a big structural problem.

Shrinkage Cracks:

These are a bit wider than hairline cracks, usually straight or diagonal. They happen as the concrete dries and shrinks.

If control joints are placed correctly, shrinkage cracks will often form neatly along those lines. Like hairline cracks, they’re usually not a serious structural issue unless they widen a lot due to other problems.

Structural / Settlement Cracks:

These are the cracks that homeowners should pay close attention to. They are usually wider (often more than 1/4 inch, or the thickness of a pencil), go deep into the concrete, and frequently cause one side of the crack to be higher or lower than the other.

These cracks are a major warning sign. They tell you that there’s significant soil settlement, voids beneath the slab, or a serious issue with the concrete’s support.

If left alone, these cracks will get worse, creating dangerous trip hazards, and can even lead to water issues near your home’s foundation in areas like Monmouth County or Bergen County.

When these cracks appear, it often means the concrete itself is sinking, which is a problem we solve.

Spalling and Popouts:

Spalling is when small, shallow pieces of concrete flake off the surface. Popouts are similar but involve small pieces breaking out, often leaving a conical hole.

These are usually surface issues caused by things like too much water in the concrete mix, improper finishing, or damage from de-icing salts (which are common on NJ driveways in winter). While a sealer can help prevent these, ensuring overall concrete stability is also important.

Different Ways to Fix Concrete Cracks

Before you choose a way to fix a concrete crack, it’s important to think about a few things. Is the crack inside or outside? Will the concrete move when the weather freezes and thaws?

Inside concrete usually doesn’t move from freezing, so you can use stiff materials like special cement or epoxy.

But cracks in outdoor concrete or concrete that might move need a flexible product, often applied with a caulk gun, to stop them from breaking apart again.

Here are some common methods used to repair concrete cracks:

Epoxy Injection:

This method is often used for cracks in very strong concrete, like in building foundations. It involves injecting a thin, liquid epoxy resin into the crack. The epoxy fills the crack, then hardens, acting like a super-strong glue.

This can make the concrete strong again, especially if the crack is structural. However, if the concrete slab is still sinking or moving, the new epoxy might just crack again.

Polyurea Injection:

Like epoxy injection, polyurea injection puts a liquid material into cracks to seal them up and stop water. What’s special about polyurea is that it stays flexible after it dries.

This makes it good for cracks that might see some slight movement, like those indoors or in places with small temperature changes.

It helps seal and waterproof the crack, but it doesn’t fix the underlying cause if the concrete slab itself is sinking or shifting a lot.

Concrete Resurfacing:

This method is great for cracks that are just on the surface and don’t go very deep. It involves putting a thin new layer of special concrete material over the old surface. This covers up minor cracks and makes the whole concrete area look fresh and even.

It’s a good way to make your concrete look better without a huge cost. But, it’s very important that the cracks are not deep, and the concrete won’t move from freezing weather.

If you resurface over a crack that’s going to move or get bigger, that crack will likely show up on the new surface too.

Crack Routing and Sealing:

For wider cracks (say, up to an inch wide), this is a common way to seal them. First, special tools like a hand grinder with a diamond blade are used to make the crack a bit wider and remove any loose dirt or pieces inside it.

This helps the sealant stick much better. After the crack is cleaned, it’s filled with a foam rod or sand, and then a strong, flexible sealant is put on top.

This helps keep water out of the crack, which is key to preventing more damage.

However, this method mainly seals the crack from the top; it doesn’t fix the problem if the crack appeared because the concrete slab is sinking or moving underneath.

Carbon Fiber Stitching or Reinforcement:

When cracks are very serious and show that the concrete structure itself might be weak, carbon fiber can be used. This method is about making the cracked area much stronger.

Workers might cut small grooves across the crack and then glue a strip or bar of carbon fiber into those cuts with a strong epoxy.

Sometimes, carbon fiber strips are glued right over the cracked surface. This adds extra support and helps stop the crack from getting bigger or moving more.

This method adds strength to the concrete, but it won’t re-level a slab that has sunk due to soil problems underneath.

Joint and Crack Fillers:

These are the flexible materials you often see put into cracks, like silicone or polyurethane sealants. They are commonly used for small to medium cracks, especially outdoors, where concrete will expand and shrink with temperature changes.

These flexible fillers can handle slight movements in the concrete and are good at keeping water out. While they are crucial for protecting the concrete from water, they won’t fix a crack if the concrete slab is actively sinking or moving due to problems with the ground underneath.

These fillers often come in solid colors, which can stand out. Sometimes, sand (close to the concrete color) is sprinkled on top of the wet filler to help it blend in better.

Preventing Concrete Cracks: Smart Steps for New Jersey Homes

The best way to deal with concrete cracks is to stop them from happening in the first place! Here are some key strategies to prevent cracks in your concrete, which is especially important for protecting your home.

Proper Concrete Mix and Curing:

Making sure your concrete is mixed and cured correctly from the start can greatly reduce cracks. This means using the right amount of water with the cement and good-quality stone or gravel.

“Curing” is the process where concrete slowly hardens and gains strength. If it dries too fast, it’s more likely to crack. For example, in New Jersey’s warm, dry summers, concrete needs to be kept moist while it cures.

Also, the thickness of your concrete matters a lot. Concrete that’s too thin or not designed for its use is much more likely to fail.

• For places where only people walk, like walkways and patios, 4 inches of thickness is usually enough.
• For areas that get regular car traffic, like driveways, 6 inches is recommended.
• Concrete slabs that will see heavy truck traffic need to be designed even thicker for their specific use.

Using Control Joints (and Expansion Joints):

Concrete naturally shrinks a little as it dries and expands/contracts with temperature changes. Control joints are intentional cuts made in the concrete to give it a planned place to crack.

Think of them as pre-made lines where cracks should happen, preventing bigger, uglier, uncontrolled cracks elsewhere. The way these joints are spaced depends on the concrete’s thickness and design.

Expansion joints are a bit different.

They are put in during the concrete pouring. These are wider gaps, often filled with a flexible material, placed against things like masonry walls or other concrete slabs.

They allow the new concrete to move freely without pushing against other structures, stopping cracks that could happen from pressure.

Reinforcement and Strong Design:

Adding materials like steel bars (rebar), wire mesh, or special fibers inside the concrete makes it much stronger and better able to handle weight.

This “reinforcement” helps spread out any stress on the concrete, greatly lowering the risk of cracks caused by too much pressure or shifting. It’s like giving the concrete an internal skeleton.

Regular Check-ups and Upkeep:

Even with the best planning, it’s smart to regularly look at your concrete. Catching small issues early can stop them from turning into big, costly problems.

For instance, if small cracks do appear and you don’t address them, things like de-icing salts used in NJ cities during winters can settle in those open cracks.

This can lead to further damage and break down the slab over time. Promptly fixing small cracks helps protect the whole slab.

Waterproofing and Sealing:

Applying waterproof coatings or sealers to your concrete surfaces is a powerful way to prevent cracks. These layers stop water from soaking into the concrete.

This protection is key for fighting damage from freeze-thaw cycles (when water freezes and expands inside concrete) and also prevents corrosion (rusting) of any steel reinforcement inside the concrete. Protecting against water is a simple step to add years to your concrete’s life.

When Your Cracks Mean a Deeper Problem Needs Fixing

It can be hard to know when to call in the experts. If you notice any of these signs with your concrete cracks, it’s a strong indication that you need more than just a surface repair, and our concrete leveling service is likely the answer:

• Your cracks are wider than 1/4 inch (about the thickness of a pencil) and appear to be growing.
• The cracks are uneven, creating trip hazards or causing water to pool.
• You see cracks that are allowing water to seep into your home’s foundation or basement.
• Cracks are extending through multiple concrete slabs, indicating widespread movement.
• The cracks are accompanied by visible sinking or settling of concrete around them.

These are precisely the situations where we provide the definitive, lasting solution for homeowners.

Get a Free Assessment for Your Concrete Floor!

Don’t let concrete cracks devalue your home or become a safety hazard any longer. If you’re dealing with structural cracks, sinking concrete, or trip hazards, we offer a lasting solution with our professional concrete leveling.

We don’t patch cracks; we fix their root cause, leading to a stable and often closed crack.

We provide free, no-obligation estimates for homeowners and businesses across the state. Whether you’re in Freehold, Toms River, Woodbridge, or anywhere else in New Jersey, we’re here to help.

Call us today for a free inspection and quote, or fill out our online form to learn how we can bring your concrete back to level and stable condition.