DAP Concrete and Mortar Filler and Sealant, Gray, 10.1 Oz

Cracks have a way of multiplying once you start seeing them. After a spring walkthrough of my property turned up a handful of hairlines in the driveway, a gap along the garage apron, and a suspicious joint near a basement window well, I reached for DAP’s concrete sealant. I wanted something simple to apply, weather-resistant, and paintable if the color missed the mark. Over several projects and through a season of rain and heat, this gray, water-cleanup sealant proved to be a dependable option for non-structural concrete and masonry repairs.

What it is and what it isn’t

This is a ready-to-use, gray concrete and mortar filler that loads into any standard caulk gun. It’s a flexible, water-based formula—low odor, no flammable solvents—that tools easily and cleans up with soap and water before it skins over. Think of it as a weather-sealing, movement-tolerant crack filler rather than a structural patch. If you’re dealing with spalling, big voids, or broken edges that need rebuilding, a cementitious repair compound is the right path. For narrow cracks, gaps at control joints, and seams where water likes to sneak through, this sealant fits the bill.

Application: straightforward and forgiving

Surface prep is half the job with any sealant, and this one responds well to good prep. I wire-brushed loose concrete, vacuumed dust, and made sure the surfaces were dry. The tube nozzle trims cleanly; for most cracks I cut a small opening for a 1/8" to 3/16" bead. For anything wider than about 1/4", I added backer rod to control the sealant depth and avoid wasting material.

The sealant lays down with a creamy, controllable consistency. It doesn’t run on horizontal surfaces and has only minimal slump on verticals if you don’t overload the joint. I found I had a comfortable tooling window—long enough to work a 6–8 foot section before it began to skin. A damp finger or a caulk finishing tool leaves a smooth, slightly concave profile. It doesn’t stick aggressively to tools the way pure silicone does, which makes cleanup and shaping easier.

One practical note on volume: a single 10.1 oz tube goes a long way with hairline cracks—dozens of linear feet—but wider joints chew through it quickly. Plan for extra tubes if you’re filling expansion joints or deeper gaps with backer rod.

Performance: weather-tight and reliably flexible

After cure, the sealant sets to a firm, rubbery consistency that moves with seasonal shifts better than rigid patch compounds. In my driveway, it bridged hairline cracks and sealed a 3/8" joint between the slab and the garage apron without splitting through a summer of heat and a late-spring downpour. I returned the area to foot traffic the next day as directed; for vehicle traffic I waited a full 24 hours and saw no marking or displacement.

Water resistance is solid. I used it to seal a seam along a basement window well where wind-driven rain had found a path. After a few storms, no seepage. On the driveway, it shrugged off a week’s worth of dew and a splash of soapy wash water without swelling or softening. The product literature calls out resistance to gasoline, salt, grease, and oil after cure; my limited “real-world” version of that was a drip of motor oil and a shovel-full of late-season deicing salt. Neither stained or degraded the bead.

Color and finish

The color is a medium gray that generally blends with typical broom-finish concrete. “Blend” is doing some work here, though—concrete varies wildly in shade based on age, sand, cement content, and weathering. On one lighter section of walkway, the sealant read as a bit darker. If uniformity is important, the fact that it’s paintable is helpful. I’ve had good results topcoating with a latex masonry paint after full cure to unify the color.

The cured finish is smooth and slightly satin. It doesn’t pick up dirt excessively, though like any joint it benefits from an occasional hose-off if you want it to look fresh.

Odor and cleanup

One reason I reach for this type of sealant for small indoor jobs is the low odor. I used it in a utility room around a slab penetration and didn’t need to ventilate beyond what I’d normally do. Cleanup before cure is as easy as advertised—soap and water for tools, and a damp rag for stray smears. Once it sets, it’s tenacious; plan your tooling and have rags handy so you’re not scraping cured material off adjacent surfaces.

Where it fits in the toolkit

• Driveways and walkways: Sealing hairline to modest cracks, control joints, and slab-to-slab gaps to keep water out and resist freeze-thaw damage.
• Garage floors and aprons: Filling slab-to-foundation seams and small surface cracks where grit and fluids collect.
• Masonry walls: Caulking minor gaps in mortar joints or around penetrations; it adheres well to both concrete block and poured concrete.

If you’re dealing with wide expansion joints on heavily traveled driveways or pool decks, a polyurethane or self-leveling joint sealant may offer more long-term elasticity and abrasion resistance. If you need to rebuild broken corners or fill deep voids, a sandable, cement-based repair mortar is the right tool. This DAP product slots neatly into the middle ground where flexibility and ease of use matter more than compressive strength.

Durability over time

Over the months I’ve had it down, I haven’t seen edge separation, checking, or peeling. The bead remains flexible and has not collected significant surface cracking under sun exposure. Winters are the real test for freeze-thaw zones, and while I can’t claim multi-year data on these specific repairs yet, the formulation’s flexibility and water resistance are promising indicators for longevity in those conditions.

Practical tips for best results

• Prep thoroughly: Brush and vacuum cracks; the cleaner the edges, the better the bond.
• Control depth: Use backer rod for gaps wider than 1/4" to set a proper hourglass profile and conserve material.
• Don’t overfill: Slightly proud is fine; tool to a smooth, concave finish that sheds water.
• Mind the weather: Aim for a dry day with moderate temperatures to avoid washout or extended cure times.
• Paint for uniformity: If color matching is critical, plan to topcoat with a latex or oil-based paint after full cure.

Value and convenience

The combination of water cleanup, low odor, and 24-hour return to service makes this sealant easy to integrate into weekend maintenance. It’s less fussy than solvent-based products, more forgiving to apply, and still provides the flexibility and weather resistance most homeowners need for routine concrete and masonry sealing.

Bottom line

DAP’s concrete sealant is a straightforward, effective choice for sealing non-structural cracks and joints in concrete and masonry. It’s easy to apply, cures in a day, holds up to moisture and common driveway contaminants, and can be painted when appearance matters. Color match isn’t perfect on every slab, and it’s not a replacement for structural repair compounds or heavy-duty joint sealants in high-movement applications. But used where it’s intended, it delivers dependable results with minimal hassle.

Recommendation: I recommend this sealant for homeowners and pros who need a reliable, paintable, water-cleanup option for small to medium concrete repairs and joint sealing. It strikes a practical balance of ease, performance, and versatility, and it’s a product I’m comfortable keeping on hand for routine maintenance.