Essential Tips for Asphalt Concrete Driveway Repair
This article is presented by Pavemade as general guide to asphalt driveway repair. We feature our asphalt and concrete crack repair and seal products such as the Easy Melt Hot Asphalt Crack Filler, Driveway Asphalt Tape, High BTU Propane Torch, HOTBOX 10, HOTBOX 30, along with our Patching, Crack filling, and Sealcoating materials. This article also discusses other products and options available on the market.
The Cost of Driveway Repair
When a driveway has potholes and cracks, it can definitely bring down the overall value of your home, as well as kill your curb appeal. If you are in the process of selling your home, the prospective buyer’s experience of driving onto the driveway sets the expectations going forward. Prospective buyers form an opinion the moment they spot the home. Don’t let some potholes in your driveway slow down your sale. Maintaining your driveway can be an inexpensive way to help retain the maximum equity in your home and avoid expensive asphalt driveway resurfacing.
There are various types of driveways but they are all some combination of binder and aggregate. Over time the water, sun, and other oxidizers degrade the binder so aggregates loosen and crack apart. Once water makes its way into the cracks, problems will worsen quickly, especially if your home is in a colder climate with multiple freeze-thaw cycles. Patches placed under winter conditions have a shorter life expectancy than patches placed in the spring.
Freeze–thaw weathering is caused by water inside driveway cracks. When water freezes its volume expands, creating forces which cracks spall off the outer surface. As this cycle repeats the outer surface repeatedly undergoes spalling, resulting in weathering.
Getting Started with Planning
Driveway projects should be planned out over several warm and dry days as this will provide the optimum conditions for binding. You may also need to wait several weeks between patching and sealcoating. Driveway repair should always begin with cleaning, crack filling, and patching as required followed by sealcoating. When working with stone, slow is fast. Longer cure times for masonry mixes of aggregates and binders leads to significantly longer useful lifespan for your driveway.
Step 1. Inspect your Driveway
The simplest scale for rating the severity of defects in a driveway is low, medium, and high. Be sure to view the driveway from more than one direction and height while you inspect to assure you don’t miss seeing any cracks or birdbath ruts.
Ranking the severity of cracks: Cracks in driveway need to be properly filled to prevent foundation problems over time.
Low severity — Hairline and very thin cracks. The cracks have very little or no spalling along the edges and are less than 1/4-inch in width. These cracks should be classified as Low Severity.
Medium severity — The cracks have little or no spalling but they are greater than 1/4-inch in width. There may be a few randomly spaced low severity connecting cracks near the main crack or at the corners of intersecting cracks.
High severity — Cracks are spalled and there may be several randomly spaced cracks near the main crack or at the corners of intersecting cracks. Pieces are visibly missing along the crack.
Ranking the severity of potholes or rutting: The average rut or pothole depth in the driveway will determine the ranking. Recommended ranges for estimated severity are as follows. Always observe the predominant severity and if there is equal severity use the highest severity.
Low severity — 1/4-inch to 1/2-inch
Medium severity — 1/2-inch to 3/4-inch
High severity — over 3/4-inch
Step 2. Prepare your Driveway
You want to remove any loose material such as dirt and rocks from potholes and cracks. This can be easily accomplished with a broom, masonry brush, masonry hammer, brick set, screwdriver, or cold chisel. A High BTU Propane Torch can also be used to remove any grass or weeds from cracks before they are filled. Before you throw out your old asphalt remember, recycled asphalt pavement is the largest volume of recycled material in the world. With a few simple steps you can reuse your old asphalt.
Step 3. Crack Filling
For the strongest chemical bond hot asphalt crack filler is the preferred choice. You can easily rejuvenate asphalt by heating it to 350 degrees with a High BTU Propane Torch and remixing the softened asphalt with an asphalt rake or lute. Asphalt in this form is often called “hot mix asphalt” or HMA.
Hot rubberized crack filler is usually sold in two 30 LBS or 50 LBS blocks and Crack Fill Rolls of 30 LFT or greater. Pavemade sells our own premium Easy-Melting Hot Crack Filler Block, compatible with both direct fire and oil jacketed asphalt crack fill equipment. Pavemade manufactures a single-operator push behind asphalt crack fill machine called the HOTBOX 10 and a
stationary 30 GAL capacity asphalt heater called the HOTBOX 30. For long driveways and big parking lots, Pavemade runs a deal that gives a free crack fill machine for each pallet of crack filler you buy.
A time-saving trick for blocks is to cut them into smaller pieces to speed up melting time. Pavemade offers smaller 20 LBS blocks that can speed up the melting time.
One of the simplest ways to repair large driveway cracks is with stone dust and rubberized crack filler tape. Once you fill in the deep cracks with stone dust (or sand) to about half an inch to the top, apply burn-on asphalt tape on top of the cracks then use a propane torch to heat it up so the melted rubberized asphalt will flow into the cracks and bond to the crack walls. For cracks that are deeper than ½’’, pour sand or stone dust into the crack up the ½’’ below the surface of the driveway. For small cracks or hairline cracks, use the tape directly. A tip is to also heat up the asphalt pavement on both sides of the crack prior laying down the tape as this will also help overall bonding.
When torching the Tar Tape, make sure to use a high BTU torch like this one to thoroughly melt the tape; it should melt down in less than a minute. The melted material will self-level. You will get the same long lasting results as professionals. For a smaller lot this is a faster way but the “per linear foot” material cost is higher compared to melting blocks.
Pavemade also sells a self-sealing asphalt tape that does not require torching, it's called Peel & Seal Tar Tape, which is everything you need to repair asphalt and concrete driveway cracks. This self-sealing driveway tape is a different formulation and will level up with the pavement under foot traffic or vehicles driving it over time. The tip for this self-sealing asphalt tape is to make sure to apply some pressure (stepping on it or use a heavy roller) after you lay it down.
Step 4. Patching
There are a number of patching products on the market. Cold Patch material will work well in most cases if you need to do a quick job. Just remember you may be doing that “quick job” more often when you use cold patch. Hot patching provides the adequate level of energy so that the chemical bonding becomes much stronger between the binder and aggregate in the asphalt. Hot patching will make your repair last longer. Heating, done safely with a propane torch, is the most energy efficient way to rejuvenate asphalt so that it’s just as strong as fresh asphalt. Pavemade offers a High BTU Propane Torch to prepare the asphalt for this purpose. There are also a number of asphalt rejuvenators that can be sprayed into a hot mix asphalt. The rejuvenators add oils and resins to the asphalt that are naturally lost over time.
Preparing the pothole: The right way to fill a pothole is to fill it with straight or sloped edges. Straight edges are the simplest. A sloped edge where the bottom is wider than the top will push the hardening forces inward and result in a better seal. Whether undercut or not, sloped edges will increase the surface area and therefore strengthen the bonding between the old and new patch.
If your pothole has reached the base layer, you will want to examine the base layer for compactness. It is recommended that the base layer should be 4” to 8” thick and well compacted. If additional material needs to be added, stone dust can be used to fill in the base layer.
Stone dust is also commonly known as stone screenings, quarry dust, grit, or decomposed granite. Unlike sand, it also effectively keeps weeds and grass from growing through your driveway holes and cracks.
If you decide to fill the pothole with stone dust you want to make sure you compact it before adding asphalt patch. You can use an 8” X 8” steel tamper for big potholes - for smaller holes a hand trowel or the top of a hammer can be used to compact the stone dust. Fill the pothole with stone dust up to the beginning of asphalt layer. 4” to 6” is the average thickness of asphalt driveways. A couple of thin layers of compacted stone dust as binder will always improve adhesion at the bottom of the pothole regardless of its depth. For thicker asphalt pavements, always lay it down as 2-3" layers at a time, tamping down each layer.
Next, fill the hole with your hot or cold patch. Patch is available in 50 LB bags at most home repair supply stores, and Pavemade offers our own premium BOND-X Green HP Pothole Patch in a variety of volumes.
A quick tip: leaving the bags in the hot sun for a couple of hours will improve your results.
A single 50 LB bag should be enough for a hole that is 12” X 12” X 4” in depth. Remember you want to overfill the hole at least 1 in. Once filled, spread the asphalt with a combination asphalt rake and asphalt lute. The lute is used to smooth out the asphalt before final tamping.
Once the hole has been patched you can use an 8” X 8” steel tamper to compact the patch so that it is level with the driveway. The more tamping and compaction the faster it will cure. Patch needs to cure before you can seal your driveway. It is recommended to wait a minimum of 30-90 days for a patch to fully cure, but in reality you may be able to seal much faster if weather conditions are good. A good way to tell is that if the asphalt patch is tacky or shiny then it has not fully cured. Once fully cured, if you do a good clean job it will look as good as new!
Step 5. Sealcoating
Once your cracks and potholes have been filled it’s time to seal your driveway with sealcoat. Sealcoat is a protective coating for roadway/pavement surfaces. It will protect your driveway from UV damage and water as well as prevent cracks and ruts. You will also see sealcoat sold as alligator patch. Whether it is called sealcoat or alligator patch when it comes to filling cracks it is only recommended for hairline cracks. If you have actual large alligator cracks you may have a more serious base or subgrade issue that may require re-paving. You can find sealcoat in 5 LQD GAL buckets in most Lowes or Home Depot stores. Pavemade sells Sealcoat in 1 or 5 LQD GAL buckets.
Sealcoat can be applied with an asphalt squeegee or sprayed. Depending on the square foot area, spraying can be faster. The squeegee method can save you on equipment costs. Either way you will want to make sure to mix your sealcoat well for best results. If you use a squeegee, pour out material along the width of your driveway. Start at the highest point and work your way down the driveway. Use the long squeegee to evenly spread out the sealcoat over the driveway taking care not to seal past the edges of your driveway.
One trick is to lay an inch or two of gravel on either side of the driveway to catch any sealcoat that spills over the driveway. Sealcoat is a very sticky material like paint and is not easy to remove from unwanted surfaces. Citrus based cleaners are your best choice for cleaning any mess you make.
You may want to use a smaller sealcoat brush on the edges for better control. Most sealcoat comes with a small amount of silica or sand. You can always add sand to sealcoat to give the driveway more texture and added grip. Applying two coats of sealcoat will provide better long-term results. But make sure to let the first layer dry for several hours before applying a second layer. The first layer should be dry to the touch. Once finished let the sealcoat dry for at least 24 hrs. before walking or driving on the driveway.