Paving industry professionals agree that late spring and summer remain the ideal times to lay asphalt and take on asphalt repairs. Does that mean you cannot schedule a paving job during the autumn months? Many homeowners plan to improve the curb appeal of their home with a paved driveway and walkway, choosing asphalt as the most affordable alternative. But is it too late in the year to get started on those plans?
Take a closer look at the characteristics of asphalt paving and why warm weather provides the ideal conditions. This will help you to understand whether or not autumn is advisable for paving projects.
Prime Conditions for Asphalt
Hot mix asphalt requires a certain temperature to compact and set properly it must generally remain between 175 and 275 degrees. Colder weather may shorten the time span allowed for installation, but asphalt quality can be retained as long as the mix remains within stated temperatures. Warmer air temperatures in spring and summer help the mix to remain in a pliable state. When the mixture cools down compression becomes more difficult and stability degrades.
Who You Hire Makes a Difference
Set up of the asphalt paving work crew also makes a difference to quality. It's best to hire an experienced asphalt crew that works with the proper equipment. An efficient installation process allows for higher levels of quality in any weather, but speed and proficiency become even more important in colder temperatures.
Asphalt must be installed in a timely manner. Companies not set up for peak efficiency have little problems in the spring and summer, but when these firms install driveways and pathways in the fall trouble can result. The longer hot asphalt sits without being properly compacted, the less stable it is. And when inclement weather causes the contractor to delay applying the top layer, more structural problems result.
In colder temperatures (around 40 to 45 degrees Fahrenheit) a thin layer of asphalt (1.5-inches) must be completely compacted within 16 minutes. Thicker layers of asphalt (2 to 3-inches) have an extended time of workability in the cold, due to increased internal temperatures. Contractors laying 3 inches of hot asphalt mix have about 45 minutes to get the surface compacted and ready.
Ensure that your contractor has adequate rollers and operators to complete the job quickly. Rollers used on driveways tend to be narrow, and often just a few laborers are on site to assist with the installation. Talk to the contractor beforehand and find out how long the project will take the shorter, the better.
Why Not Simply Start With a Hotter Mix?
Since asphalt must remain at a certain temperature for the duration of installation, It would make sense to start with a hotter mix in cooler weather. But this solution presents several problems, both for the installation crew and the asphalt plant.
First of all, creating hot mix asphalt at higher temperatures requires more fuel and reduces production at the asphalt plant. This results in higher costs for the contractor, and that premium tends to be passed on to the homeowner. Are you prepared to pay a higher price for this solution? Conservative estimates state that raising the mix temperature by 25 degrees reduces production levels by at least 15 percent.
Using hotter mixes also presents a greater risk of asphalt failure due to aged or damaged binders. Pushing the temperature of a mix higher changes the composition, which results in performance alterations. It is also easier to apply a thinner coating on the aggregates, resulting in lower levels of stability and strength in all weather.
Transporting the hot mix from the plant to your property also allows the temperature to drop. Many asphalt plants supply tarps or wrap for the trucks in autumn, preventing the hot mix from cooling off too much.
Ask your contractor whether any measures are taken to ensure the mix will not cool during transport. If you live in a rural area or are located a fair distance from the local asphalt plant, consider waiting until the spring to pave.
Asphalt plants in many parts of the country are open for business until the snow flies. If production continues and transportation concerns are taken care of, your contractor should give the go ahead for your project.
Special Treatment of Recycled Asphalt
Recycled asphalt is being used for many applications today. But when recycled or planed asphalt cannot be resurfaced for more than ten days in the cooler temperatures of autumn, a temporary layer of hot mix asphalt is required. This temporary layer must be at least 2-inches thick and should be properly marked.
These standards most often apply to roads and parking lots, but unpredictable fall weather conditions can leave your driveway resurfacing project in a bind.
Asphalt Repairs in the Fall
Completing asphalt repairs may be easier in the fall, depending on the type of repair and scope. All of the same rules apply the hot asphalt mix must be delivered at the right temperature and laid down in an efficient manner. Infrared asphalt repairs produce the best results by maintaining the mix at peak temperatures (using a hotbox) and heating up the existing asphalt to facilitate bonding.
Other types of asphalt repair can be successful, but temporary asphalt layers must be replaced within a short period of time. Talk to your contractor about the ideal methods and processes, as well as the options of adjusting the schedule to attain long lasting results.
Paving in the autumn presents a variety of challenges for the asphalt plant, contractors and homeowners. If you need to have asphalt paving installed in cooler temperatures, be sure to understand exactly what to watch out for and keep a close eye on the conditions of your materials and worksite. Hire an experienced paving contractor that has handled a wide range of projects and ask about how the hot mix is transported between the plant and your home. With all conditions taken care of, paving in the autumn can be done well.Posted by: TrustedPros