How to Repair Cracks in Asphalt Driveway

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 Cracks in Asphalt Driveway

Source: https://home.howstuffworks.com/home-improvement/home-diy/flooring/driveway-cracks3.htm