One of the best parts about Minnesota is the clear separations of the four seasons. But for as beautiful as the seasonal changes are, they bring with them some unique challenges for paving companies like J&W Asphalt, and for most of the year, paving isn’t even an option. But all is not lost, and in this article, we’ll explore the right conditions for paving and when it’s time to jump on a project so you can plan your next project with confidence.
When is it time to Repave?
Picking the right time to repave depends on a number of factors including the age of the lot or driveway in question and how much traffic it receives. In general, a well-applied asphalt lot should last for 20 years. But, if you’re noticing potholes and cracking covering a substantial portions of your project, it is likely time for repaving if you want to avoid damaging your or your customers’ vehicles. Alligator cracks—named for their resemblance to the animal—can be the first sign that repaving is in order.
Temperature is key
Asphalt can be a fickle customer, so ensuring compaction is complete before the substance cools to below 220 degrees can be a challenge as unpredictable as the Minnesota weather. That’s why the experts at J&W Asphalt aim for the warmest possible days. If the asphalt cools to below 180 degrees, you can forget about compacting it into shape any further.
For Shaun Johnson, owner of J&W Asphalt, these temperature windows mean quality assurance is crucial.
“This is why we test the asphalt temperature at the plant, as we pave, and during the rolling and compaction processes,” Johnson said.
This is also why applying asphalt is best left for the hottest days possible.
Water is a really hard substance to squeeze into a tighter space than it already occupies. This property in part is what makes garden hoses work because water, instead of shrinking into a smaller space like air does, will find the nearest opening to escape through when put under pressure. While this might be a neat factoid, water’s inability to be compressed can make it difficult to properly prepare for paving. If the ground of prospective asphalt project is saturated with water—usually because of thawing snow or irrigation systems— grading and smoothing the surface can be unpredictable. This brings us to the next topic…
Good soil and water management go hand-in-hand. In general, sandy undersoil that drains out moisture is preferable to soil with lots of clay underneath. Clay will trap moisture, which makes drainage difficult. J&W gets around this by laying a few inches of aggregate rock and another couple inches of sand to allow for water to escape, leading to vastly extended life of the pavement.
Ensuring the best possible product
Minnesota’s unique climate brings along with it some unique challenges for paving companies. To meet these challenges, J&W Asphalt uses specially designed asphalt, which is foam-injected. This helps the asphalt spread evenly on and the sand and gravel laid on top of the subsoil. J&W also heats its asphalt to higher temperatures during days that are colder than ideal.
“The asphalt we use is designed for Minnesota’s freezing and thawing climate,” Johnson said.
Irrigation systems are the most common cause for moist soil at the sites J&W visits, so if you know you have an upcoming paving project, be sure to turn off your system at least a week ahead of time to allow for the ground to dry. Sometimes it becomes clear that old pavement has trapped moisture, so the company will allow the ground to dry before repaving if this is the case.
There are also things you can do to make a project go smoothly if you know J&W is going to be repaving for you:
· Don’t run your irrigation the week of your driveway dig out and installation.
· Make sure we can open your garage door and have enough space to roll in and out of your garage.
· Read and follow the expectations and guidelines we send to every customer.
· If you need a retaining wall near the driveway, get that completed before we do the driveway work.
· If you need concrete work done around the driveway, get that completed before we the driveway work.