To install a professional asphalt driveway, it is not enough to have the best materials or the most efficient contractors. These may be important, but you must also consider the soil beneath your driveway, which can play a dramatic role in both its strength and durability. This is especially true in areas with wet or marshy soil, since it has a tendency to shift, settle and rot away the gravel layer that really supports your driveway. Thankfully, you can typically accommodate poor soil in the following four ways.
Thickening the Aggregate Layer
The familiar asphalt that makes up most roads and driveways is actually more of a superficial layer than the true structure of the road. The real strength of your driveway is derived from the gravel, or aggregate, layers below. These small rocks flex and push back against the weight of a passing vehicle, and asphalt is flexible enough to move with them without cracking. Soft soil, however, can cause the aggregate to move too much, particularly under the strain of a heavy truck. The simplest way to combat this is to add more aggregate below your driveway, giving it a firmer base to withstand the pressures of heavy use.
Ensuring Solid Drainage
If moisture from below is already likely to be a problem for your driveway, you will need to take extra care to ensure that it is not also encroaching from above. This means keeping your driveway elevated if at all possible and sloped downwards to encourage runoff. The last thing you want to see is standing water wearing its way through the surface of your asphalt.
Placing a Barrier Between Your Soil and Gravel
In serious cases where groundwater is likely to seep up into your driveway, it may be necessary to add an additional liner between the soil and the bottom-most layer of aggregate. These liners do not generally halt the flow of water, but instead prevent soil from creeping into the aggregate, where it can host harmful micro-organisms and hold moisture. Speak to your contractor to learn more about the types and brands available in your area.
Giving Your Driveway Time to Breathe
Once your asphalt driveway is complete, you should follow your contractor's advice regarding how long to wait before you seal it. Asphalt needs time to cure and emit natural vapors that can lead to weakness when trapped by a sealant. This is especially important when your soil is already damp, which may slow down the curing process further. By recognizing the challenges posed by your soil and planning ahead to counteract them, you should end up with the strong, long-lasting driveway you require.
My name is Sara Jenkins and I am the daughter of a plumber. As a young girl, I was not very impressed by what my father did for a living, but I loved spending time with him so I was thrilled each time he asked me to help with a repair around the house. What I didn't realize at the time was that my father was teaching me skills that would prove incredibly useful in my adult life. Today, thanks to him, I have completed a long list of plumbing jobs in my own home without the need to hire a contractor. This blog is my way of saying thank you to him by sharing all of the things that he has taught me about home repairs and construction.