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DAP Concrete Crack Filler is a dry powder of sand, cement and acrylic polymer that you pour into a crack and mist with water, and DAP Liquid Cement Crack Filler is a ready-mixed latex filler you squeeze in from a bottle. Both are cheap, easy store products for small, stable cracks up to 1/2 inch wide in walks, patios and driveways. Neither data sheet gives a stretch figure, and buyers often mention color mismatch and shrinking, so a crack that moves with the seasons usually needs a flexible repair instead.
DAP makes two crack fillers for flat concrete, and they’re quite different products under similar names. Both are fine for a small crack that isn’t moving and a poor match for one that is.
What is DAP Concrete Crack Filler?
A water-activated dry powder. You pour it into the crack, level it, mist it with water, and it hardens in place. DAP’s technical data sheet lists an acrylic polymer as the binder, and the safety data sheet shows the powder is mostly crystalline silica (sand) with some portland cement.
The data sheet says it fills cracks up to 1/2 inch wide and 1/2 inch deep in one pass, inside or outside, and that it resists UV fading, cracking and shrinking. It’s made for horizontal cracks in concrete, stone and masonry, including sidewalks, driveways, pavers and brick or block joints.
The key steps from the label:
- Start with a clean, dry, sound crack and a temperature above 35°F, with no rain or freezing forecast for 24 hours.
- Cut the spout at an angle and fill the crack slightly over the top.
- Level it with a brush, trowel or gloved finger to a feathered edge.
- Mist it lightly. The data sheet warns that overwatering can displace the filler and hurt performance.
It’s ready for light foot traffic in 4 hours. The data sheet calls for 24 hours before significant foot traffic and 48 hours before cars.
What is DAP Liquid Cement Crack Filler?
A ready-mixed liquid you squeeze into the crack, sold in a 32 ounce bottle. Despite the name, its safety data sheet lists calcium carbonate and natural rubber latex as the main ingredients, not portland cement.
The data sheet says DAP liquid cement crack filler handles cracks up to 1/2 inch wide in sidewalks, driveways, steps, patios and basements. It levels itself and dries gray.
Deep cracks take more work. The label says to fill cracks deeper than 1/4 inch with backer rod or sand to within 1/4 inch of the surface, then fill in 1/4 inch layers with 24 hours between them. It also warns that deep cracks may need more than one application because the filler shrinks as it dries.
It can take light foot traffic 30 to 45 minutes after it goes in, and it’s fully dry in about 24 hours. The label calls for temperatures between 45°F and 100°F and no rain for 24 hours.
Does DAP concrete crack filler work?
Yes, on small cracks that have stopped moving. On a crack that opens and closes with the seasons, a filler that doesn’t stretch much tends to crack along the middle or pull away from the edges.
Concrete moves. The National Ready Mixed Concrete Association notes that temperature variations cause concrete to expand and contract (opens in a new tab), and that drying slabs 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.
Neither DAP data sheet gives a stretch (elongation) figure. The powder hardens like a mortar, and the liquid’s own label expects shrinkage in deep cracks. That’s fine in a crack that stays put and a weak point in one that doesn’t.
DAP crack filler pros and cons
Both products are easy and cheap, and both are limited by how little they flex. Here’s how they compare on the label and in buyer feedback.
| Pros | Cons | |
|---|---|---|
| Ease of use | No mixing; pour or squeeze in | Powder needs careful misting; liquid needs layers in deep cracks |
| Crack size | Both rated for cracks up to 1/2 inch wide | Deep cracks need sand or backer rod first |
| Cure | Liquid takes light foot traffic in under an hour | Powder needs 48 hours before cars |
| Cold weather | Powder can go on above 35°F | Liquid needs 45°F or warmer |
| Movement | Fine in cracks that don't move | No stretch figure on either data sheet |
| Look | Both dry gray | Buyers often say the color doesn't match the slab |
| Safety | Liquid is low dust | Powder contains crystalline silica, so wear a dust mask |
DAP Concrete Crack Filler and Liquid Cement Crack Filler data sheets and safety data sheets, plus themes from buyer comments
What do buyer reviews say about DAP crack filler?
Buyers like how easy both are, and most complaints are about looks and shrinkage. These themes come up most often in buyer comments.
- Color mismatch. A common complaint is that the filler dries lighter than the slab, sometimes almost white, and leaves visible lines. Some say it stands out most when the concrete is wet.
- Shrinking and settling. Buyers of the liquid often say it sank into the crack and needed a second pass, and some found gaps left in wider cracks after several tries.
- Powder vs liquid. Some buyers say the powder fills better than the liquid. Others say a light spritz of water is all the powder needs, which matches the label’s warning against overwatering.
- Deep cracks eat product. Buyers suggest packing sand into deep cracks first, which is also what the labels say.
- Mixed results on lasting. Some report repairs that came through a snowy winter fine. Others say the filler cracked or needed redoing within a year.
- Questions about walls. Buyers often ask whether it works on vertical or basement wall cracks. The powder’s data sheet says it’s for horizontal cracks, and the liquid is self-leveling, so it runs out of a vertical crack. The liquid’s listed basement use means floors.
The color complaint applies to almost any patch. The NRMCA says repair material will not match the color and characteristics (opens in a new tab) of the original concrete.
DAP crack filler vs the slab crack kit
The UV slab kit fills the full depth of the crack with urethane-soaked sand and tops it with a flexible polyurea. The DAP products fill with a mortar-like powder or a latex that has no published stretch figure.
| DAP Concrete Crack Filler (powder) | DAP Liquid Cement Crack Filler | UV slab crack kit | |
|---|---|---|---|
| Type | Sand, cement and acrylic powder | Ready-mixed latex filler | Urethane over silica sand, topped with polyurea |
| How it cures | Hardens after misting with water | Dries in air; shrinks in deep cracks | Two parts react in the mixing nozzle |
| Ready for traffic | Light foot 4 hours, cars 48 hours | Light foot 30 to 45 minutes, fully dry about 24 hours | Light traffic 30 minutes, full traffic 60 minutes at 70°F |
| Flexibility | Not stated on the data sheet | Not stated on the data sheet | Polyurea top stretches 170% and cures rubber-like |
| Sunlight | Data sheet says it resists UV fading | Not addressed on the data sheet | UV-resistant polyurea top on the UV kit |
| Crack width per label | Up to 1/2 inch wide and deep | Up to 1/2 inch wide | Up to 1/4 inch; 1/8 inch and under is ground out first |
| Deep cracks | Fills up to 1/2 inch deep in one pass | Sand or backer rod to within 1/4 inch, then 1/4 inch layers a day apart | Sand packed to 1/4 inch below the top and soaked with urethane |
| Minimum temperature | Above 35°F | 45°F | Concrete at least 50°F |
DAP data sheets and safety data sheets, and the CR304 and CR305 slab kit data sheet
The kit’s urethane is thin enough to soak into the sand and the crack walls, so the repair bonds from the bottom up. Its data sheet says the urethane doesn’t become brittle, and the polyurea top cures to a hard, rubber-like material that moves with the slab.
For a basement floor, the indoor slab crack kit uses the same sand and urethane fill, with no polyurea top. The how to repair cracks in concrete guide walks through it, and the retail vs pro-grade comparison explains when a store product is enough.
Who should buy DAP crack filler anyway?
If your cracks are small, stable and mostly a looks problem, either DAP product is a cheap, reasonable fix. Pick by the job:
- The powder for pavers, brick and stone joints, or cool days down to the mid 30s °F. Wear a dust mask and gloves; its safety data sheet warns about crystalline silica dust.
- The liquid for hairline to narrow cracks you want walkable in under an hour, on a day that’s 45°F or warmer.
- Either one as a stopgap to keep water and weeds out until you can do a full repair.
Skip both for driveway cracks that reopen every winter, cracks wider than 1/4 inch, and anything on a wall. The guide to why crack repairs fail covers what to do when a filled crack keeps opening.
Which cracks need more than a filler?
Cracks that show the concrete has moved need a diagnosis first. No filler fixes the cause.
- A slab crack wider than 1/4 inch, or one where one side sits higher than the other. See the large cracks guide and sinking slab guide.
- A 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 go to a structural engineer, not a product.
For other cracks, the concrete crack repair hub and the product chooser will point you to the right fix.
Questions
How long before you can drive on DAP Concrete Crack Filler?
The data sheet says light foot traffic after 4 hours, significant foot traffic after 24 hours and vehicles after 48 hours. Keep rain and freezing off it for the first 24 hours.
Is DAP Liquid Cement Crack Filler actually cement?
Not in the usual sense. Its safety data sheet lists calcium carbonate and natural rubber latex as the main ingredients and doesn't list portland cement. It dries gray, which is where the name comes from.
Can you use DAP crack filler on a basement wall?
No. The powder's data sheet says it's for horizontal cracks, and the liquid is self-leveling, so it runs out of a vertical crack. Basement wall cracks are covered in the foundation crack repair guide.
How much do you need?
DAP's data sheet says one bottle of the powder covers about 34 linear feet of crack 1/2 inch wide and 1/2 inch deep. The liquid's data sheet says a quart fills a crack 1/4 by 1/2 inch for about 35 feet. Filling the bottom of deep cracks with sand first stretches either one.