Can you sealcoat over cracks in asphalt?

No, and it is the most common mistake we get called out to undo. Seal coat is roughly the thickness of a heavy coat of paint. It flows into a crack rather than bridging it, so the crack telegraphs straight back through the new black surface within weeks and water keeps running into the base underneath. Cracks get filled with hot rubberized sealant first, then the sealer goes over the top.

How do I know if my parking lot needs repaving instead of repair?

Look at how much of the lot is failing and whether the failures are connected. Isolated potholes and a few soft spots in an otherwise solid lot are patch work, even if there are several of them. When alligator cracking has spread across large connected areas, when patches you put in a year or two ago are already breaking apart, and when the surface is unraveling in more than one place at once, the base is the problem and a new surface layer is the honest answer.

What is alligator cracking and why does it matter so much?

Alligator cracking is a web of interconnected cracks that looks like reptile skin, and it is a structural signal rather than a surface one. It means the gravel base under the asphalt has lost its support, usually because water got in, so the pavement flexes under traffic until it fractures in a grid. Filling those cracks or sealing over them does nothing, because the failure is underneath. That area has to be cut out, the base repaired, and new asphalt laid in.

How often should a parking lot be sealcoated?

For most pavement in Clark County, every two to three years keeps the surface protected. High-traffic commercial lots and driveways that get full sun tend to need it on the shorter end of that range. The tell is color and texture: when the surface has gone from black to grey and the individual stones start feeling proud of the surface underfoot, the binder is oxidizing and it is time.

Is sealcoating worth it, or is it just cosmetic?

It does both jobs, and the protective one is the reason to do it. A seal coat blocks water, UV, and oil from reaching the binder that holds the asphalt together, which is what slows oxidation and raveling. The cosmetic payoff is real too, and it is the part tenants and customers notice. What sealcoating cannot do is add strength, so it is worth it on sound pavement and wasted money on pavement that has already failed structurally.

Should You Sealcoat, Patch, or Repave Your Parking Lot?

This is the question we get asked more than any other, usually phrased as some version of "can we just seal it?" It is a fair question and it deserves a straight answer, because the three options are not interchangeable and picking the wrong one costs real money. Sealcoating a lot that needs patching is money you will spend again next year. Repaving a lot that only needed crack filling and a seal coat is money you did not need to spend at all.

The good news is that asphalt is honest. It tells you what is wrong with it if you know how to read the surface. Here is how we make the call when we walk a lot in Vancouver, Battle Ground, or anywhere else in Clark County.

What sealcoating does and what it cannot fix

Start here, because most of the confusion comes from expecting sealcoat to do a job it was never designed for. A seal coat is a thin protective layer applied over the top of existing asphalt. It goes on about as thick as a heavy coat of paint. What it does is block the three things that age pavement fastest: water, UV, and petroleum. Those attack the asphalt binder, the black glue holding the aggregate together, and once the binder oxidizes the surface goes grey, gets brittle, and starts shedding stones.

So sealcoat is preventive. It buys years on pavement that is still structurally sound. What it adds is zero. It contributes no strength, it does not bridge a gap, and it does not care what is happening in the gravel six inches down. Put it over a crack and the crack comes back through. Put it over a soft spot and you have a black soft spot.

That is the whole rule, and everything below is just applying it. Asphalt sealcoating protects good pavement. It does not rescue bad pavement.

How to read the cracks in your asphalt

Walk the lot slowly and look at the shape of the damage rather than the amount of it. The pattern tells you which layer has the problem.

A rural asphalt driveway lined with maples and arborvitae, with sealed cracks showing as dark lines across the surface and a white chalk layout line running down the middle — Straight, isolated cracks like these are routine aging. Sealed before winter, they stay a maintenance item instead of becoming a base failure.

Straight, single cracks

Long cracks running roughly straight, either along the direction of traffic or across it, are the normal way asphalt ages. They come from thermal movement, from the pavement shrinking and expanding through our winters, and from joints in the original paving. As long as they are isolated lines rather than a network, the pavement underneath is fine. These are exactly what crack filling and sealing is for, and catching them at this stage is the single highest-value thing you can do for a lot.

Alligator cracking

A web of interconnected cracks in a patch that looks like reptile skin is a different animal entirely. This is fatigue cracking, and it means the base under the asphalt is no longer supporting the load. Usually water is the culprit: it got in through cracks you did not seal, it saturated the gravel, and now the pavement flexes under every truck until it fractures into a grid.

Nothing you apply to the surface will fix this. The area has to be saw-cut out, the failed base dug out and rebuilt, and new asphalt compacted into the hole. That is asphalt repair and patching, and it is the step people most often try to skip.

Potholes

Potholes are alligator cracking that nobody dealt with. Once the surface fractures into pieces, traffic and water pull those pieces out and you have a hole that grows every wet month. They get patched, and the patch has to go down to solid material rather than just filling the bowl.

Raveling and loose stone

If the surface feels gritty, the stones look exposed, and you find loose aggregate along the edges and in the corners, the binder has oxidized and the pavement is coming apart from the top down. Caught early, sealcoating stops it. Caught late, when the surface has lost enough material to be visibly rough and pitted, sealing it just glues down a failing surface for a season.

Standing water and birdbaths

Puddles that are still sitting there a day after the rain stops are a grade problem, not a surface problem. In Clark County this matters more than it does in a dry climate, because standing water is a permanent supply of the exact thing that destroys pavement from below. A birdbath can sometimes be corrected with a leveling patch. Widespread drainage failure is a design issue that needs to be solved before any surface work is worth doing.

When crack filling is the right call

If the lot has straight cracks, holds its shape, drains, and has no soft or spongy areas, you are in the best possible position: your pavement needs maintenance, not repair. Fill the cracks, and if the surface has gone grey, seal it.

Crack filling is unglamorous and it is the highest-return work in this trade. Every crack you seal is water that does not reach the base, and nearly every expensive pavement failure we get called out to started as a crack somebody watched get wider for three winters. The wet season here does not need much of an opening to do damage.

When you need patching instead of sealcoat

Any alligator cracking, any pothole, and any area that feels soft or moves under a vehicle needs patching before anything else happens. The test we use on site is simple: if we would be embarrassed to see a seal coat go over it, it gets repaired first.

A dark rectangular asphalt patch set into a lighter concrete apron, cordoned off with orange delineator posts, with a red dump truck parked alongside a commercial building — A failed area cut out and patched back in, cordoned off while it sets. Repairs like this happen before any sealer goes down, never after.

Patching an area does not mean the whole lot is done for. A commercial lot with three or four failed areas and otherwise sound pavement is a completely normal candidate for cut-and-patch repair followed by crack filling and a seal coat. That combination gets you a lot that looks new and, more importantly, is protected for the next several years.

When it is time to repave

Repaving becomes the honest answer when the failures stop being isolated. The signals we look for:

Alligator cracking spread across large, connected sections rather than a few defined areas.
Patches placed a year or two ago that are already failing at the edges, which tells you the base problem is bigger than the patch.
Raveling across most of the surface, so there is no sound layer left to protect.
Drainage that has never worked, where the grade itself needs to be rebuilt.

Being straight about the reverse is just as important: a lot that looks tired does not need repaving. Faded color, worn-out stripes, and a scattering of cracks describe a lot that needs maintenance, and anyone who quotes you a full replacement for that should be asked to explain the base failure they are seeing. If they cannot point at it, it is not there.

The order the work has to happen in

Once you know what the lot needs, the sequence is fixed. Doing it out of order wastes whatever you spent on the step you did too early.

Repair first. Cut out and patch the failed areas, and fix the drainage problems that caused them.
Crack fill second. Hot rubberized sealant into every working crack, because sealer will not bridge them.
Sealcoat third. Over a clean, repaired, dry surface, cut in by hand at the edges.
Stripe last. Fresh parking lot striping goes over cured seal coat, never under it. This is also the natural moment to bring the layout up to current ADA requirements, since the lines are coming off anyway.

A commercial lot at dusk with bright white stall lines freshly painted around concrete wheel stops, a white service truck parked at the edge and roll-up doors behind — The end of the sequence. Striping goes down last, over cured seal coat, which is why layout changes are cheapest to make at this stage.

Timing matters too. Sealcoating needs dry weather and warm ground, which in the Pacific Northwest means a real season rather than a year-round option. If you are planning work, our guide to the best time to sealcoat here covers the window. Crack filling and patching have a much wider range, so they are usually what we do while waiting for a seal window to open.

The honest summary

Most lots we look at in Clark County need less than the owner feared and more than they hoped. They need a few areas patched, the cracks filled before another wet season gets into them, and a seal coat to hold the line for the next two or three years. That is a maintenance budget, not a capital project, and the lots that get it on a schedule are the ones that never turn into a capital project. If you want to think about it as an ongoing plan rather than a one-time fix, our parking lot maintenance schedule lays out what belongs in which month.

And if you would rather not diagnose it yourself, that is genuinely fine. We walk lots and driveways all over Clark County and tell people what we see, including when the answer is that they do not need us yet.