How to Repair Driveway Cracks


Photo courtesy of Dreamstime

Because most driveways are subjected to the elements on a full-time basis, they do occasionally experience cracks. Driveway cracks are most common in regions of the country that experience freeze/thaw cycles which wreak havoc on concrete and other solid ground materials. In most cases, cracks in the driveway aren't a serious problem and can be fixed with relatively simple solutions. The key is fixing a driveway crack before its condition is worsened by moisture entry, erosion of the underlying ground or subsequent freeze/thaw cycles.

If you happen to have a gravel or dirt driveway, then you don't need to worry about cracks. Potholes, bumps, and dips, however, can form quickly in gravel and dirt driveways. Water is also the main culprit that causes these problems, so regardless of your driveway's material, try to ensure that water can drain easily away from the area. Dirt and gravel are very simple materials with which to work, so the problems that arise will be simple to repair. In most cases, you will only need to add more or dirt or more gravel, but there can be a bit more to it.

Be sure to read the instructions and safety precautions when using any specific products to repair cracks in your driveway. In many cases, the materials used for these repairs require special safety precautions. Depending on your chosen method of repair, the job may also require special tools or equipment. At a basic level, the materials you'll likely need to fix a crack in your driveway include:

  • Appropriate protective clothing
  • A small hammer (either a mason’s hammer or a small, hand sledge hammer)
  • Protective goggles and gloves
  • Broom
  • Wire brush
  • Mason's chisel or large flat screwdriver
  • Pointing trowel
  • Air compressor, canned air or shop vac
  • Water (either from a garden hose or a spray bottle filled with water)

By taking the time to repair the crack, you can help avoid more serious and costly driveway issues. In this article, we'll show you how to fix driveway cracks by reviewing the techniques used in the three most common types of driveways -- concrete, asphalt and brick pavers.

How to Repair Concrete Driveway Cracks

An attractive concrete driveway adds curb appeal to your home.
An attractive concrete driveway adds curb appeal to your home.
Photo courtesy of Dreamstime

The primary purpose of fixing concrete cracks is to help keep moisture from working its way into the cracks. A secondary benefit of fixing concrete cracks is improving the appearance of your driveway. Considering that many homes have front-facing driveways, it is a good way to help improve your home's curb appeal. Before you begin the repair, scope out the general area and try to get a feel for what caused the crack. Concrete cracks can be caused by growing tree roots, impact damage, weight overloading, etc. The most common cause of concrete cracks is standing water, which, over time, works its way into the concrete and expands and contracts according to the temperature.

Before you begin fixing the actual crack, think long and hard about how you can eliminate the cause of the problem. Preventing further damage is vital to the overall success of your repair job. The methods used to fix concrete cracks depend on the size of the actual crack.

Preparation

  • Regardless of size, the first step should include cleaning the crack to create clean surfaces that are ready to bond with the repair materials.
  • Begin by breaking off any loose pieces of concrete with a screwdriver or chisel (be cautious you don't needlessly enlarge the crack).
  • Once you've cleaned the crack's edges, use a firm wired brush to remove any remaining debris.
  • Next, remove as much loose debris from within the crack as possible. This is best done with an air compressor but if you don't have one available, you can use a shop vac or even canned air, which is commonly used to clean computer keyboards. The idea here is to clean out all of the dust and debris from within the crack.

Now that the crack has been prepared for repair, follow the steps below according to the size of the crack. Follow the specific directions that are printed on the packaging of whatever product you end up using to make your repair.

Fixing Small, Hairline Concrete Cracks

  • Textured caulk, concrete sealer or pourable grout designed for repairing concrete are good ways to fix small concrete cracks.
  • If you're using concrete sealer or pourable grout, begin by lightly wetting the crack -- a spray bottle filled with water will work well (textured caulk is best applied to a dry crack).
  • With all products, completely fill the crack and use a pointing trowel to push the grout or sealer into the crack.
  • If you're using textured caulk, provide some overfill to account for shrinkage as the caulk dries.
  • If you're wearing thick rubber gloves, you can use your thumb to ensure that you're completely filling the crack.
  • In all cases, refer to specific product manufacturer guidelines for application instructions.

Fixing Larger Concrete Cracks

For cracks wider than ½ inch, you may want to consider undercutting the crack to make sure that the crack is wider below the surface than at the surface. This will help ensure that the patching material used will not pop out of the crack when the concrete expands and contracts.

If you’re using pourable concrete grout, only apply ¼ inch of grout per application. You can either fill the crack with sand leaving ¼ inch to the surface of the crack to be filled with the grout or make multiple grout applications that are ¼ inch thick, allowing adequate time for each application to dry. Wet the crack slightly and begin filling it in with grout, applying layers no thicker than ¼ inch. Overfill the crack slightly to compensate for the slight shrinkage the grout will experience as it dries.

If you'll be using vinyl concrete patch material, be sure to follow directions and only mix as much as you can use within the specified time, which is usually less than 20 minutes. Begin by wetting the crack with a spray bottle or hose. Spread the patch material into the crack using a pointing trowel, paying attention to fill the crack in layers no thicker than ¼ inch. Vinyl concrete patch material shrinks as it dries so applying it in layers will allow you distribute a more equal distribution that is less likely to crack. Once your initial layer has had enough time to dry (per package instructions -- usually a couple of hours), proceed with additional applications until the crack is full.

If you choose to use textured caulk, keep in mind it has to be applied to a dry surface. If the crack you're repairing is deeper than 3/8 inch, fill the crack with sand or foam backer board. Cut off the tip of the applicator to a size that matches your crack, not exceeding ¼ inch (refer to caulk manufacturer provided guidelines). In addition to completely filling the crack, apply some overfill to account for shrinkage as the caulk dries.

As you're finishing applications, use a pointing trowel to blend the final patch material with the surrounding concrete to form a good seal of the crack. Once you are done filling the crack, use a small brush, broom or even a block of wood to rub across your patch to help match the consistency of your patch surface with the surface of the original concrete. If the concrete cracks continue to reappear, call in a professional to rule out any larger problems.

How to Repair Asphalt Driveway Cracks

A well-maintained asphalt driveway makes a great impression.
A well-maintained asphalt driveway makes a great impression.
Photo courtesy of Dreamstime

Asphalt is by far the most common material used for paving driveways. And just like the asphalt we see lining our streets and highways, asphalt driveways can develop cracks and dips over time. It’s important to fix these cracks in a timely manner to protect the durability and appearance of your driveway. Fortunately, fixing cracks in an asphalt driveway is a simple process that only requires a do-it-yourself spirit and a few tools and materials that are readily available at most hardware stores.

The most frequent cause of cracks in your asphalt driveway is water that has seeped below the surface and expanded or contracted with freezing and thawing temperatures. After patching and filling any cracks or dips in your asphalt driveway, you may also wish to seal your driveway to prevent any further water seepage.

Preparation

  • Before patching the crack, it is very important for the affected area to be as clean and smooth as possible so that the patching material can adhere easily.
  • You should start by using a hammer and chisel to remove any broken pieces of asphalt obstructing the crack.
  • Next, use a wire brush or a wire wheel on a drill to remove dirt and debris from the crack.
  • Finally use a compressed air gun or a shop vac to ensure that all of the loose debris and smaller particles have been removed. If neither an air gun, nor shop vac is available to you, you can use a garden hose to flush out the crack. However, if you use a garden hose, you must let the crack dry completely before continuing.
  • Regardless of what you use to clean the crack, it’s recommended that you wear safety goggles to prevent and debris from harming your eyes.

Once you have cleaned the crack in the asphalt thoroughly, you are ready to begin filling the crack. Be aware that smaller and larger cracks require different patching materials. The following steps will instruct you on how to fix both smaller and larger cracks.

Fixing Smaller Cracks in Asphalt (1/8 in - 1/2 in)

  • To fill smaller cracks you should use rubberized asphalt-emulsion crack filler. Try to avoid getting any of the filler on unaffected areas as it can stain the driveway.
  • Apply the filler using a caulking gun if available. If you don’t have a caulking gun, the filler can be poured carefully into the crack.
  • Use a putty knife or trowel to smooth out the surface of the crack. If a putty knife or trowel is non’t available, you can use rubber gloves and smooth the crack out with your thumb.
  • Let the filler dry according to the instructions on the packaging before driving over the affected area.

Fixing Larger Cracks in Asphalt (>1/2 in)

  • If the crack you are trying to patch is deeper than two inches, you may wish to first fill the crack up to the two inch mark with small, crushed, angular gravel. Don’t use pea gravel or other larger gravel as it can shift frequently and does not provide an adequate base.
  • Next, you should compact the gravel using a steel tamper or a 4x4 wooden post.
  • Now fill the crack with a cold process asphalt repair compound, such as blacktop.
  • Compact the compound with a tamper or a 4x4 wooden post.
  • After compacting, you may need to add more blacktop or compound material and repeat the tamping process to ensure a consistent, level driveway.

While the surface blacktop will dry in a day or so, the blacktop beneath may take a few weeks to completely harden. Don’t seal your driveway during this period as it will prevent air from getting to the patch and it will not harden properly.

How to Repair Cracked or Chipped Brick Pavers

Brick driveways look great and are relatively inexpensive to maintain.
Brick driveways look great and are relatively inexpensive to maintain.
Photo courtesy of Dreamstime

Fixing cracked or chipped brick pavers is a very simple task. Because it takes so many bricks to build a driveway, replacing individual bricks that have cracked or chipped is relatively inexpensive. The best way to care for brick pavers, however, is to have them sealed right after they are installed. Sealing brick pavers will help to ensure that they last a lifetime and it will also decrease the likelihood of the bricks cracking or chipping.

Of course, not all damage can be prevented by sealing the bricks. Everyday accidents are likely to occur, and your driveway will most likely suffer damage from the occasional contact with bike pedals or dropped items. When accidents happen, there is no need to fret. You can always pry up the damaged brick and replace it with a new one. There are steps that can be taken to prevent damage and erosion that are not caused by human error. These measures are vital to the longevity of your brick paved driveway.

Prevention

  • Inspect your brick pavers on a regular basis, particularly after harsh weather like rain or snow.
  • Regularly sweep or pressure clean your paved driveway to remove damaging materials and debris.
  • Seal and reseal your pavers on a regular basis to protect them from stain damage and the effects of high traffic usage.

When damage cannot be prevented, the cracked, chipped, or crumbling bricks will need to be replaced. Loose bricks also need to be dealt with immediately, because they can lead to injury. Replacing brick pavers is a simple task, especially if your bricks are whole and not cut to fit into a particular design.

Replacing Loose or Damaged Brick Pavers

  • Mark each side of the loose pavers with a marker before they are removed to ensure that you are replacing the correct brick.
  • Remove the brick paver and clean all debris from the area.
  • Place a layer of sand down and, using a wooden float, push the sand into all of the corners. Tread on the sand to really compact it.
  • Check the level of the sand base with a spirit level.
  • Match up the chalk markings and place the new brick paver into the area.
  • By using a screwdriver, make sure there is an even gap between the new brick paver and the surrounding pavers.
  • Pour sand on top of the replacement bricks, so that the gaps are filled evenly.
  • Using a mallet, tap the new pavers into place, then sweep the excess sand away.

If the bricks that make up your driveway are cut into different sizes, then you will need the proper tools for shaping and sizing them. There are many different types of tools that can be used to cut and shape brick pavers, so be sure to choose the right tools for your repair purposes.

Paver Hand Tools and Methods

  • A lump hammer is often used for splitting pavers. The paver is first measured and marked to fit into its slot. Then, while supporting the paver, you must strike it several times from left to right, working your way to the center. This should allow you to split the paver to your desired size.
  • Chisels are excellent tools for precise procedures like trimming pavers. After using a lump hammer to split a brick paver, you will often have to trim the side that was split. Work the chisel slowly to ensure that no mistakes are made. Continue trimming the brick paver until the desired size or smoothness is attained.

Paver Power Tools and Methods

  • Powered saws are great for cutting your pavers to a specific size. They work quickly and often require no trimming. The various types of power saws include bench saws, floor saws, table saws and cut-off saws.
  • The cut-off saw is the most popular power saw today. It is a hand-held saw that can cut many different materials. If you decide to use a power saw, make sure that you get the right type of blade for cutting brick pavers.
  • Power splitters can split many different types of materials, and there are two different types: block and slab splitters. They are available in both hydraulic and manual operating modes. The manually operating splitters can use special blades for cutting irregular pavers.

The type of tool you should use depends entirely upon the state of your brick paved driveway. If you need to replace a lot of the bricks and they all need to be cut to size, then you might think about using power tools. Otherwise, hand tools should suffice.

How to Repair Potholes in Dirt and Gravel Driveways

Dirt and gravel driveways tend to have less overall form than concrete, asphalt or brick driveways, but dips, bumps and potholes are just as great a nuisance. Because of their simple structure, it’s very easy to fill a pothole in dirt or gravel driveways and requires very little effort to smooth out. Remember: potholes won’t fix themselves and if they get big enough, they can damage your car. It’s best to attack the problem as soon as it is discovered, not just for your car, but for the appearance of your driveway.

Preparation

  • Most potholes in dirt or gravel driveways are caused by water trapped below the surface, so be sure to maintain or improve the quality of underground drainage to avoid potholes reappearing in your driveway. You can do this by creating a “crown” in the center of the driveway, spreading outward. Roughly one inch of height is necessary for the “crown” for every 3-4 feet of width of the driveway.
  • Before filling the pothole, make certain that the hole is cleared of any debris or loose stones that might prevent it from being level. You can use a rake, a shovel, or even a small garden tool if necessary.
  • If the sides of the pothole are not solid, dig down with a shovel to create firm edges. This will ensure that the filler material compacts easily.

Filling a Pothole in a Dirt or Gravel Driveway

  • Start by filling the pothole with coarse gravel up to about three inches below the surface of the driveway.
  • Next you should compact the coarse gravel using a steel tamper or a 4x4 wooden post.
  • For a dirt driveway, fill the hole with dirt up to three to four inches above the desired surface level.
  •  Water the soil and compact the area using the steel tamper or 4x4.
  • If necessary, repeat the process until the dirt is compacted to the desired level.
  • For a gravel driveway, fill the remaining three inches with gravel that matches your driveway, then add a small mound of gravel on top that can be used to smooth out the area.
  • Rake the area, blending the gravel into the surrounding areas of the driveway.

For either a dirt or gravel driveway, run a car over the affected area to ensure further compaction and to be certain that your repairs have had the desired effect. Otherwise, you may need to add more dirt or gravel and repeat the previous process.