Mike Harp has been in the pavement business for over 25 years. He has seen a lot of winters. This one, he says, has kept his phone busy.
We asked Gradeline’s General Manager the questions property managers and facility directors are probably already asking: What are we really dealing with? What needs to be fixed now versus later? And what does repair actually look like?
Here’s what he had to say.
Can you talk about the winter storms we’ve seen this year and the kind of damage they’ve caused to our roads and parking lots?
The first storm of the season was significant. We had five to six inches of snow topped with three to four inches of ice. That combination alone created an enormous amount of problems. One of the biggest issues was that in many cases, the snow couldn’t be removed adequately. Cars had no choice but to drive on top of it, and parking lots and drive lanes weren’t cleared properly in time. As that compaction occurred, it forced the snow and ice directly into any areas of the parking lot that were already compromised. Then, when extreme low temperatures followed, it became a recipe for serious damage.
And there’s another factor worth understanding. Asphalt is a flexible product, that’s by design. But the colder the temperatures get, the more brittle asphalt becomes, and that accelerates failures. The difference between 32 degrees and 22 degrees, or lower, is dramatic.
What are the most common types of damage you’re seeing right now?
Potholes are the most visible. The freeze-thaw cycle drives that. Water finds its way into even the smallest crack, freezes, expands, creates a larger crack, and then it’s a domino effect from there.
What made this winter different was the extended period of extreme cold. We actually saw significant heaving: sidewalks, curbs, and asphalt physically pushing up from the ground as the frost line kept deepening. In some cases, once temperatures rose, the heaving corrected itself on its own. But heaving affects asphalt and concrete very differently. Asphalt is a flexible material, so it bends before it breaks. In some cases, the heaving reversed itself. Concrete is rigid, and when it heaves, it fractures and cracks. That damage doesn’t reverse itself.
Why does winter weather hit pavement so hard? Can you walk us through what’s actually happening to the asphalt?
It comes back to the fundamental properties of the material. Asphalt is designed to flex, the liquid asphalt in it allows for that movement. But extreme cold strips away that flexibility and makes it brittle, which means failures happen faster and more severely than they would in a milder winter. When you combine brittleness with the freeze-thaw cycle, you accelerate the breakdown significantly.
Is there damage that property owners can see right away, and damage that might be happening under the surface that they won’t notice until it’s much worse?
Potholes are the most obvious. But the more concerning damage is often what’s happening at the joints. Any paved area has seams, where two passes of asphalt were rolled and compacted together. There’s typically a joint running down the center of a drive lane and another at the edge of each parking bay. Joints are always the weakest link, and typically the first place failure begins.
Once water penetrates a crack or a compromised joint, it starts working its way into the base asphalt layer. When the base fails, it reaches the stone subgrade beneath the lot. At that point, you’re looking at saturation of the stone, which causes the pavement above it to pump and flex and eventually fail in a much more significant way. The damage you can’t see is often the damage that costs the most to fix.
When someone calls you in the spring saying their lot looks rough, what does your assessment process look like?
The first thing I want to do is get on site. I need to put eyes on it. I’m evaluating how large the affected area is, how the pavement has failed, whether it’s surface cracking or full-depth cracking, and whether there’s any stone or subgrade material showing through. From there, I’m doing a cost-benefit analysis: is it most effective to surface patch, do a full-depth patch, mill and overlay a section, or potentially replace a larger area entirely? The goal is always to get the client the best outcome for their investment.
What are the signs that tell you a repair is urgent versus something that can wait a season?
Safety comes first. Anything that poses a trip hazard or has the potential to damage vehicles needs to be addressed immediately. That’s non-negotiable.
Beyond safety, I’m looking at rate of change. Some parking lots hold on for years and degrade gradually. That’s manageable and can be planned for. But if an area is deteriorating rapidly from one season to the next, that’s a red flag that something more serious is happening beneath the surface and waiting will only make it more expensive to fix.
Walk us through the main repair options — patching, sealcoating, milling and overlay — and when each one makes sense.
Every situation is different, and the right repair depends entirely on what the assessment reveals. Patching addresses isolated failures where the damage is contained. Mill and overlay is the right call when you have widespread surface deterioration but the base is still sound. You remove the top layer and replace it with fresh asphalt. That’s why surface is often called the “wear course”. When the base itself has failed, you’re looking at full-depth replacement.
I’ll be honest: I’m not a fan of partial-depth patching in most cases. A typical surface course is about two inches thick, and the base in commercial and industrial lots in this region runs four to six inches. If I’m going to excavate four inches of a six-inch base, I’d rather take out the remaining two and do it right. That also gives me the opportunity to inspect the subgrade and understand what’s going on underneath before I put new material down.
How do you decide between a patch and a full mill and overlay? What’s the tipping point?
It comes down to how widespread the failure is and whether the base is still performing. If the damage is isolated, a handful of problem areas with solid pavement in between, targeted patching makes sense. But if failures are spread throughout the lot and the surface is showing widespread deterioration, patching becomes a game of whack-a-mole. At that point, a mill and overlay or full replacement delivers a better long-term result and is often more cost-effective over time.
If someone puts off repairs, what happens? Does the damage compound?
It absolutely compounds. Water is the enemy of pavement, and every crack is an entry point. Once water gets into the base and reaches the stone subgrade, you’re no longer dealing with a surface repair, you’re dealing with a structural failure. What might have been a patching job one spring can become a full replacement by the next. Addressing deterioration early is almost always the more economical choice.
When is the right time to start repairs after a winter like this one?
I won’t start paving work until I’m confident winter is behind us. You don’t want to put down new asphalt and then get hit with another freeze. Patience pays off here.
Are there weather or temperature conditions that affect when pavement work can be done?
Technically, Maryland State Highway specs allow us to perform base work at 32 degrees and surface work at 40 degrees. Personally, for private work I like to see consistent temperatures of 50 degrees or above before we begin. Warmer air and warmer ground make the asphalt easier to work with. It stays workable longer and lays down a smoother product. When it’s too cold, asphalt cools off too quickly and this can cause excessive handwork. We call it getting “bony”. The fine material in the mix drops out and you can see just the aggregate. The surface ends up looking rough even on fresh asphalt. Warmer temperatures don’t necessarily change how the pavement performs structurally, but the aesthetic result is noticeably better, and for a lot of our clients, appearance matters.
For a property manager trying to plan and budget, what’s your advice on how to prioritize?
Start with safety. Trip hazards and anything that could damage vehicles have liability implications and need to move to the front of the line.
Next, focus on areas that have gotten measurably worse this season. Gradual decline is manageable. Rapid deterioration is a signal that something is accelerating underneath the surface, and that warrants immediate attention.
For clients I’ve built long-term relationships with, I’ll often work within a defined budget. I enjoy the value engineering. They tell me what they have to work with, and I make sure every dollar is maximized. Those partnerships work really well for both sides. They get predictability, and I get to do the work the right way.
Any final advice for property managers who are looking at parking lot repair right now and wondering where to start?
Get out there and walk it. Look for the obvious stuff — potholes, heaved concrete, cracked edges, standing water after a rain. But also pay attention to anything that’s changed since last year. Then call us. A site visit costs you nothing, and it gives us both a clear picture of what we’re working with. The worst thing you can do is wait another season and let a manageable problem turn into a major one.