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Quikrete Concrete Crack Seal is a ready-to-use latex filler you pour from the bottle into cracks in sidewalks, patios and driveways. It's easy, cheap and sold in most hardware stores, and it does a fair job hiding small cracks that don't move. Its own safety sheet calls it a cosmetic sealant, though, and it shrinks as it dries, and buyers often report it splitting within a year or two on cracks that open and close with the seasons.
Quikrete Concrete Crack Seal is a fair choice for a quick, cosmetic fix on a small crack that isn’t moving. It isn’t built to seal a working crack for years, and the label says as much if you read it closely.
What is Quikrete Concrete Crack Seal?
A gray latex filler in a squeeze bottle that you pour straight into the crack. Quikrete’s product data sheet describes it as a latex emulsion formulated to fill cracks in horizontal concrete, and its safety data sheet lists the use as an acrylic cosmetic sealant for horizontal repairs.
It needs no mixing. The data sheet lists sidewalks, walkways, steps, patios, decks and appliance pads as uses, and it comes in squeeze tubes, quart bottles and gallon jugs.
The bottle is product number 8640. Don’t confuse it with Quikrete’s Advanced Polymer Concrete Crack Sealant, a caulk-tube product covered further down.
Does Quikrete Concrete Crack Seal work?
On a small crack that has stopped moving, yes, at least for a while. On a crack that opens and closes, it usually splits, because it isn’t stretchy enough to follow the movement.
Concrete moves all year. The National Ready Mixed Concrete Association notes that temperature variations cause concrete to expand and contract (opens in a new tab), and that a drying slab can shrink further (opens in a new tab) so existing cracks get wider. American Concrete Institute training material calls cracks whose width changes with time (opens in a new tab) “active,” and those need a flexible repair.
The label itself points to the other weak spot. It tells you to overfill slightly to allow for shrinkage, and the data sheet lists no stretch (elongation) figure. A filler that shrinks as it dries and lists no stretch figure is likely to pull apart along the middle of a crack that keeps moving.
Quikrete Concrete Crack Seal pros and cons
It wins on convenience and price and loses on how long it lasts. Here’s the label and the buyer feedback side by side.
| Pros | Cons | |
|---|---|---|
| Ease of use | No mixing, pour from the bottle | Pourable liquid made for flat, horizontal cracks only |
| Where to buy | Most hardware and home stores | Easy to grab without reading the label's limits |
| Crack size | Rated for cracks up to 1/2 inch wide | Deeper than 1/4 inch needs sand or backer rod underneath |
| How long it lasts | Holds on small cracks that don't move | Shrinks as it dries, and cracks that move split it |
| Weather | Works from 45°F to 100°F | Rain within 24 hours can wash it out |
| Look | Gray, blends with plain concrete when dry | Can show as a light line when the slab is wet |
| Coatings | Takes acrylic water-based paint | Not for slabs that will get another coating later |
Quikrete Concrete Crack Seal data sheet (product 8640) and safety data sheet, plus themes from buyer comments
What do buyer reviews say about Quikrete crack seal?
Buyers like how easy it is and are split on how long it lasts. The same few themes come up again and again in buyer comments.
- It’s easy. Buyers often say it’s simple to use, and some say it goes in neater when you let it pour slowly rather than squeezing hard.
- It cracks down the middle. A common report is that a year or two later the filler has split along the center of the crack, especially on driveways.
- Some see it as a temporary fix. Some buyers say they knew it wouldn’t last forever, got a few seasons out of it, and redo the worst spots.
- Rain is a problem early on. Reviews mention filler washing out when heavy rain came soon after it went in, which matches the label’s 24 hour rain warning.
- Color stands out when wet. Some buyers note the slab darkens in the rain while the filler stays light, so the cracks show as gray lines.
The color issue isn’t unique to this product. The NRMCA says repair material will not match the color and characteristics (opens in a new tab) of the original concrete.
Quikrete crack sealer: the bottle vs the Advanced Polymer tube
If you searched “Quikrete crack sealer,” you may want the Advanced Polymer Concrete Crack Sealant instead of the bottle. It’s a different product: a moisture-curing polymer sealant in a 10 ounce caulk tube.
Its data sheet makes much stronger claims on movement. It says the sealant stays permanently flexible, handles movement of plus or minus 25%, stretches 250 to 350% before it breaks, and works on cracks and joints up to 1 inch wide.
The trade-off is time. That data sheet says to wait at least 3 days before traffic and 3 to 7 days for a full cure, and it needs backer rod in deep joints. It’s closer to a joint sealant than a crack filler, so it suits gaps between slabs as much as cracks.
Quikrete Concrete Crack Seal vs the slab crack kit
The UV slab kit fills the whole crack and tops it with a flexible polyurea, while Quikrete fills the top with latex. That difference is why the kit costs more and lasts longer on cracks that move.
| Quikrete Concrete Crack Seal | UV slab crack kit | |
|---|---|---|
| Type | One-part latex (acrylic) filler | Urethane over silica sand, topped with polyurea |
| How it cures | Dries in air; label allows for shrinkage | Two parts react in the mixing nozzle |
| Ready for traffic | Not stated; keep rain off for 24 hours | Light traffic 30 minutes, full traffic 60 minutes at 70°F |
| Flexibility | No stretch figure on the data sheet | Polyurea top stretches 170% and cures rubber-like |
| Sunlight | Not addressed on the data sheet | UV-resistant polyurea top on the UV kit |
| Crack width per label | Up to 1/2 inch | Up to 1/4 inch; 1/8 inch and under is ground out first |
| Deep cracks | Sand or backer rod to within 1/4 inch of the top | Sand packed to 1/4 inch below the top and soaked with urethane |
| Minimum temperature | 45°F | Concrete at least 50°F |
Quikrete Concrete Crack Seal data sheet and the CR304 and CR305 slab kit data sheet
The kit’s urethane is very thin and soaks into the sand and the crack walls, so the repair is bonded from the bottom up instead of sitting on top. Its data sheet says the urethane doesn’t become brittle, and the polyurea top cures to a hard, rubber-like material that flexes with the slab.
For a basement floor, where sunlight isn’t an issue, the indoor slab crack kit uses the same sand and urethane fill, with no polyurea top. The driveway crack repair guide walks through the steps, and the retail vs pro-grade comparison covers store products against kits more broadly.
Who should buy Quikrete Concrete Crack Seal anyway?
Anyone with a few small, stable cracks who wants them filled today for little money. It’s a reasonable choice in these cases:
- Hairline to narrow cracks in a walk or patio that haven’t grown in a year or more.
- A spot you plan to paint with acrylic water-based paint.
- A quick fix to keep weeds and water out until you can do a full repair.
Skip it for a driveway crack that reopens every winter, a crack wider than 1/4 inch, or anything on a wall. The guide to why crack repairs fail explains what to do when a filled crack keeps opening.
Which cracks shouldn’t get any filler?
Cracks that mean the concrete has moved need a diagnosis before any product. Filler hides them without fixing anything.
- A slab crack wider than 1/4 inch, or one where one side sits higher than the other. The large cracks guide and sinking slab guide cover those.
- A whole panel that has sunk, tilted or heaved.
- Any horizontal crack in a basement wall, a wall bowing inward, stair-step cracks in a block wall, or a wall crack 1/4 inch or wider. Those need a structural engineer, not a product.
For every other crack, the concrete crack repair hub and the product chooser will point you to the right fix.
Questions
How long does Quikrete Concrete Crack Seal take to dry?
The data sheet doesn't give a dry or traffic time. It says to keep rain off it for 24 hours and to wait 24 hours before a second coat. Plan on a full dry day before you walk or drive on it.
Can you paint over Quikrete Concrete Crack Seal?
Only with acrylic water-based paint. The data sheet says not to use it on surfaces that will later get any other coating, so skip it if you plan to put a solid sealer or epoxy on the slab.
Does Quikrete Concrete Crack Seal work on basement walls?
No. The data sheet says it's made for cracks in horizontal surfaces, and as a pourable liquid it runs out of a wall crack. Basement wall cracks are covered in the foundation crack repair guide.
How much crack does one bottle fill?
The data sheet says a quart fills a crack 1/4 inch wide by 1/2 inch deep for about 38 feet. Filling the bottom of deep cracks with sand or backer rod first, as the label says, makes it go further.