How to Repair and Seal Your Asphalt Driveway
So often when we think of home repair, we focus on areas inside the house first. Then we shift our attention to the exterior portions of the house, often forgetting that the driveway is an extension of the home. I know from experience that this is often the case. When we purchased our house, we spent the first two years working on the inside, painting walls, stripping wallpaper, replacing carpeting. During that period, we spent time landscaping, adding trees and bushes, planting perennials and incorporating annuals. Lost in the frenzy of work was the asphalt driveway that introduced people to our home. After two years of wear and tear, it began to show our neglect, with small cracks and discoloration. Before long, the cracks widened, eventually forming small pits and potholes. We realized the mistake we had made and were determined to mend our ways and our driveway. The problem was, we weren’t sure where to start.
As with any project worth doing right, we began by seeking information, in part to understand how asphalt worked, and to understand why the damage was occurring. Here is some of what we discovered:
• What is it made of? Asphalt is a black substance formed from a combination of gravel and the residual leftovers of the distillation of petroleum. The petroleum residue is used as a binder to hold the gravel together. When this combination is heated and packed together, it forms a very hard, very sturdy surface, perfect for roads and driveways.
• Why is it a good substance to use in driveways? Asphalt is water resistant and elastic enough to withstand rigorous weather conditions, which would cause buckling and heaving in other materials. It has tremendous compression strength, allowing it to withstand use by heavy vehicles.
• How long should it last? Asphalt has a relatively good longevity when used in driveways. It has the capacity to last fifteen to twenty years. Having said this, as with any surface, it can crack and wear down without proper maintenance. Holes can appear as well, if minor problems are not dealt with.
• What causes the damage to asphalt? Weather is the primary culprit. When temperatures change, it stresses the materials in asphalt. In cold weather, precipitation can build up on the driveway, causing water to seep into the semi porous surface. When this water thaws and freezes, it creates expansion in these pockets, causing cracks to form. The cracks allow more water to seep in, and the process gets worse and worse. If the cracks are not fixed when the weather warms up, the cracking is compounded with each successive year. Also, the buildup of car oil and the chemicals used to melt snow and ice during the winter can help break down the asphalt surface even more.
• When should damage be fixed? The initial answer is as soon as it is detected. However, if detection occurs during the cold winter months, it is best to wait until the weather warms up. The weather must remain clear, with no precipitation, and the temperature must remain above 45 degrees for a minimum of 24 hours. Asphalt is difficult to work with when it is cold, and you will not get the kind of quality bonding and sealing that you would in warm weather. It would be better to wait until late Spring to expend the effort. You will get much better results that way.
Once we were armed with knowledge, we focused our attention on fixing the holes and cracks that had developed across our driveways. Here is what we did to mend each area:
Repairing the Cracks
1. Sweep the area around the crack to remove organic debris and pebbles.
2. Clean any gravel fragments or organic matter from the crack itself. Remember weeds and grass seek out cracks to grow in. You want to make sure that no portion of the plant is left. Otherwise, the roots will grow and regenerate the weed or grass, again helping the crack to reform.
3. Once the area is clean, use a caulk gun loaded with a high quality asphalt patching compound to fill the cracks.
4. Using a trowel, press the asphalt compound into the crack, making sure that the compound is smooth and free of dirt, gravel, and organic debris.
5. Using a brush or paint roller, apply a good coat of asphalt sealer to the patched crack and surrounding area. This will create a waterproof barrier and will help bond the crack with the surface.
1. Sweep the area around the hole to remove organic debris and pebbles.
2. Clean any dirt, rocks, gravel fragments, or organic matter from the hole itself.
3. If there are loose pieces of asphalt around the edges of the hole, carefully remove them. The outer edge of the hole must be clean, firm asphalt, otherwise the patch will not bond properly.
4. If the hole is deep, pack the bottom of the hole with clean, coarse gravel, stopping when the hole is halfway filled or when the gravel is about 3 to 4 inches from the rim.
5. Add asphalt until the level is one inch from the rim.
6. Use a trowel or small shovel to jab the asphalt, removing any air pockets that might have formed in the fill process. This is very important. Air pockets will provide areas for moisture to collect. When it freezes, the water will expand, creating a larger problem than when you began.
7. Tamp down the asphalt, either with a tamper or a long section of 4x4. This will help compact the asphalt, ensuring even fewer air pockets.
8. Fill the rest of the hole with asphalt until it is half an inch above the rim line.
9. Tamp down the asphalt until it is smooth and even with the rest of the surface. Remember, if you are using a 4x4 to tamp, the longer the piece, the heavier it will be. The heavier it is, the better tamping compression you will get.
10. Sprinkle the patch with a layer of sand. This will prevent things from sticking to the asphalt.
11. If one is available to you, pack down the asphalt with a lawn roller. This will ensure that the patch is completely level. If a lawn roller is not available, drive your car wheel over the area. The weight of the car will pack down the asphalt Again, the focus is removing as much air as possible.
12. Using a brush or paint roller, apply a layer of asphalt sealer over the entire area, concentrating on the patch and the surrounding area. Allow it to set undisturbed for 24 to 48 hours.
13. Once the sealer has set, apply another coat of sealer to the same area, allowing it to set undisturbed for the same amount of time.
With the cracks and holes fixed, you can now apply sealer to the entire driveway. Sealing is an important part of maintaining the integrity of the asphalt. Treating your driveway every year or two will extend the life of the drive, even to the point of carrying it beyond the normal lifespan.
Taking care of your driveway is worth the effort. A beautifully maintained drive will add to the surrounding beauty of your home, cutting a graceful path through the landscape of your yard. Be the envy of the neighborhood by showing them what a perfect driveway can do for curb appeal.