What is the actual difference between resurfacing and replacing?

Resurfacing leaves the existing slab in the ground and bonds a new wearing layer on top of it, typically a polymer-modified overlay a fraction of an inch thick. Replacement breaks out the old slab, re-works the base underneath, and pours a new one. The first is a cosmetic and protective treatment on a sound structure. The second is a new structure. They are not two grades of the same service.

How do I know whether my slab is still sound?

The useful test is not how the surface looks, it is whether the slab is still behaving as one piece sitting evenly on its base. Sections that have shifted relative to each other, a slab that rocks or clicks under a vehicle, cracks that are wide and stepped rather than hairline, sunken areas, and edges that have crumbled through the full depth all point at a base or structural problem. An overlay on top of any of those reproduces them within a season or two.

If the slab is sound, why not resurface everything?

You generally should. When the underlying concrete is intact and level, an overlay is the better economic decision by a wide margin and it also lets you change the finish. The failure mode is not resurfacing - it is resurfacing something that needed replacing, which converts a large one-time cost into a smaller cost you pay twice.

Will a resurfacing hide existing cracks permanently?

No, and any bidder who says otherwise is selling. A crack that is still moving - because of settlement, tree roots, or seasonal ground movement - will telegraph back through an overlay, because the overlay is bonded to the thing that is moving. Cracks that have been stable for years are a much better candidate, and a competent installer will treat and detail them rather than simply covering them.

Does drainage matter for this decision?

More than most homeowners expect, and it is the most commonly skipped part of the conversation. Water that ponds on a driveway or runs under its edge is frequently the reason the slab failed in the first place. Resurfacing over a drainage problem re-buys the same failure with a nicer finish on it, so if a bidder never asks where the water goes, that tells you something about the bid.

Replace the Driveway or Resurface It? How to Tell Before the Bids Arrive

Almost every homeowner with a tired driveway gets two very different numbers, and the gap between them is large enough to make the decision feel like a budget question. It is not really a budget question. Resurfacing and replacement solve different problems, and the right one is determined by the condition of the slab in the ground rather than by what you would prefer to spend.

Start with the slab, not the surface

Surface condition is a poor guide. A driveway can look genuinely awful - stained, spalled, faded, hairline-cracked all over - and still be a perfectly sound slab that is an excellent overlay candidate. Another can look tolerable from the street and be structurally finished.

The signals that point at replacement rather than resurfacing are about movement and support:

Differential settlement. Adjacent sections sitting at different heights means the ground under them is no longer supporting them equally.
Rocking or clicking sections. A slab that moves under a vehicle has voids beneath it.
Wide, stepped or branching cracks. Distinct from stable hairline cracking, which is normal shrinkage behaviour.
Full-depth edge failure. Crumbling that goes all the way through rather than surface flaking.
Ponding water. A drainage or grading fault that an overlay cannot correct.

Any one of those means the problem is underneath, and anything bonded to the top of it inherits the problem.

What resurfacing is genuinely good at

Given a sound slab, an overlay is one of the better-value exterior projects available. It restores the wearing surface, covers staining and spalling, and is the point at which you can change the appearance entirely - a broom, textured or stamped finish over concrete that would otherwise have been demolished and hauled away. It also avoids the disposal cost and the disruption of breaking out a slab, which on a residential driveway is not a small part of the total.

The conditions it needs are specific though: a clean, sound, properly profiled substrate, cracks assessed and detailed rather than skimmed over, and a bond coat suited to the product. Overlay failures are overwhelmingly preparation failures.

The middle options nobody offers you

The choice is often presented as two options when there are usually four, and the middle two get skipped because they are smaller jobs:

Repair only. Replacing one or two failed sections of an otherwise sound driveway, leaving the rest alone.
Slab lifting. Where the concrete itself is fine but has settled, injected material can raise sections back to level for far less than replacement. Worth asking about specifically, because a crew that only pours will rarely raise it.

Ask about both before accepting a full-replacement number on a driveway whose only real fault is one sunken bay.

Getting a second opinion that is not a bid

Because both services are sold by the same trade, it is worth checking the vocabulary against a neutral source. The American Concrete Institute maintains the consensus standards for concrete repair and construction, and the American Concrete Pavement Association publishes technical material specifically on concrete paving - including the distress types that separate a surface problem from a base problem. Neither sells driveways, which is what makes them useful here.

What to have every bidder put in writing

Their assessment of the slab, stated separately from their assessment of the surface.
Where the water currently goes, and whether the proposed work changes that.
For an overlay: the surface preparation method, how existing cracks are treated, and the product and thickness.
For a replacement: thickness, base preparation, reinforcement, and joint layout.
Whether partial replacement or slab lifting was considered, and why it was ruled out.

That last question is the most revealing one on the list. A contractor who has already thought about the cheaper option and can explain why it does not apply to your driveway is giving you an assessment. One who has not considered it is giving you a product.

Reading real prices for both paths

Because the two paths differ by so much, it helps to see them costed side by side rather than in isolation. Our recommended California crew has written up how resurfacing and full replacement compare on a Los Angeles driveway, with the decision criteria and both sets of numbers in one place. If you are in another market the rates will differ, but the criteria that decide which column you belong in do not.