If you are planning to lay asphalt, then there are several things that you need to consider before doing so. One of the biggest factors when it comes to laying asphalt is which material will be used as the base of your new driveway or parking lot. It’s important to choose the right base because it will determine how smoothly your asphalt can be laid, how long it will last, and how well it will withstand abuse from weather and traffic. While there are many different kinds of base material on the market today, we’ll talk about how asphalt bases work and which base is the best for asphalt paving so you can install your own driveway or make improvements to your existing one.
The base you choose has a direct impact on how your asphalt or pavement will perform over time. Choosing an asphalt product depends largely on what will be using it and its durability requirements. It’s important to consider these factors when deciding whether to use hot mix, cold mix, modified asphalt or gravel as a base material. Each one can affect your choice of surface and sub-base, just as each project is different. Not sure where to start?
First, what is your project: parking lot, driveway or public road? Will it be used only by vehicles (parking lot) or will pedestrians use it too (sidewalk)? How often will it be used and where will it be located (temperature extremes and weather conditions)? What is your budget? How much time do you have to complete your project?
There are several different types of base materials, each designed for a specific application and use. Do your research to determine which one will be best suited to your project.
The biggest difference between asphalt and blacktop is that asphalt is made up of asphalt cement, fine aggregate (crushed stone) and bitumen. Whereas a blacktop’s main ingredient is asphalt cement with an addition of a filler material to give it color. Another difference would be that asphalt has greater tensile strength than blacktop. In short, your driveway will last longer if laid with an asphalt layer over a concrete base than if laid with a blacktop layer over concrete.
When deciding which base to use, it is important to know what your purpose is. If you want a driveway that will be used primarily by a car then it’s best to go with blacktop because asphalt can crack and crumble under heavy traffic loads. However, if you’re looking for something durable enough to support light vehicles as well as foot traffic then you should opt for an asphalt layer.
Thickness refers to how deep your asphalt layer is laid. Because driveway thickness can be measured in several different ways, you may have difficulty determining how thick your driveway will be until it’s completed. Typically, asphalt driveway thickness ranges from 1 inch to more than 3 inches. Driveway specialists generally agree that 3 inches of asphalt is good for a comfortable and safe surface, but there are situations where less or more would work better.
How thick your asphalt is ultimately depends on what type of material you’re using. For example, when layering asphalt over a concrete base, it’s best to use a thicker layer to help withstand heavy traffic, since concrete isn’t as strong as other types of pavement and can eventually deteriorate under high traffic volume. If laying down an asphalt driveway over dirt or gravel, it doesn’t matter how thick your asphalt layer is.
The base has to be strong enough to support a heavy load, and porous enough to let water drain through. Concrete is an excellent sub base for driveways, but it’s hard to maintain once it is installed. Fine grading of aggregate adds porosity and drainage but makes concrete more prone to cracking. That’s why asphalt is often used instead, gravel does not need as much compaction, but doesn’t offer as much cushioning as some other types of aggregates do.
To understand why asphalt is a better sub base for a driveway, let’s look at how concrete and gravel differ. Concrete is an excellent sub base but it takes weeks to set. Gravel makes a good sub base because it drains well, which reduces moisture problems that can damage asphalt and make potholes more likely. However, gravel doesn’t offer much cushioning when cars drive over it, which means your ride will be less comfortable.
There are mixed opinions about putting asphalt over old asphalt. Some say that you shouldn’t even consider laying down a new coat of asphalt if there is already an existing layer of asphalt because you will inevitably have problems with cracking and potholes. But, there are others who say that it is possible to lay down an effective new layer if done properly. The truth is that yes, you can, but it takes a lot of knowledge and skill to ensure everything goes well.
Crushed stone, gravel or sand? Ask any asphalt paving contractor and you’ll get a different answer. Some might tell you that crushed stone is best because it stands up to water well and doesn’t allow weeds to grow through. Others will argue that gravel makes for a firmer surface, with better load-bearing capacity. And then there are those who swear by using nothing but sand as a base.
Like a lot of home repair jobs, each method has its pros and cons. So which is best? The truth is that there isn’t one best base for asphalt—it all depends on your climate, terrain and driveway location.
If you live in a climate with cold winters and heavy rainfalls, use crushed stone. If you have sandy soil, you should consider using crushed stone or gravel. If your area is flat and level and has no problem with weeds or rocks popping up through your driveway, then sand will be fine. If you live in an area where it snows frequently, then gravel makes sense as well. Basically, if your base layer gets watered regularly (or even if it doesn’t), go with crushed stone.
Paving an asphalt driveway costs $4,920 on average. That’s a high price tag and it’s important to make sure it’s ready to withstand traffic and weather.
If you're looking to hire an expert company for asphalt paving services, reach out to our team at Dallas Asphalt Paving.