Quikrete Rapid Setting, Hydraulic Water Stop Cement, Sets in 3 to 5 Minutes to Patch Concrete & Masonry, For Pools and Foundations, 10 Pounds

Why I keep a bucket of Quikrete Water-Stop on the shelf

I keep a small bucket of hydraulic cement in my shop for one reason: when water is actively finding its way through concrete, you don’t have time for long cure schedules or wishful thinking. Quikrete Water-Stop has become my go-to for those jobs. It’s a specialty mix designed to plug leaks in concrete and masonry, and it sets in three to five minutes. That rapid set is both its superpower and the thing you need to respect to get good results.

What it is and where it shines

This is a rapid-setting hydraulic cement for stopping water where it’s not supposed to be: basement cove joints, tie-rod holes, pipe penetrations, pool skimmers, and cracks that weep under hydrostatic pressure. It’s formulated for use above or below grade, and it’s perfectly at home around constantly damp areas.

I’ve used it to stop a persistent weep at the wall-to-slab joint in a basement and to seal around a PVC pipe sleeve that had begun to seep after a heavy storm. In both cases, the product grabbed fast, expanded slightly as it set, and stayed watertight.

Packaging and first impressions

The 10-pound size comes in a plastic pail with the powder sealed in a bag inside. The bucket is handy for storage and for mixing small batches, but the inner bag means you’ll want a scoop or cup to portion out powder without making a mess. The powder is a fine gray, typical of hydraulic cements, and has no decorative finish ambitions—it’s purpose-built for function.

Setup and mixing

• Prepping the surface is non-negotiable. I chip or grind out cracks to form a keyed recess (think of an inverted “V” that’s wider inside than at the surface). This gives the patch something to lock into mechanically.
• Clean aggressively: remove loose material, paint, efflorescence, dirt, algae, or mildew. Vacuum dust; a stiff brush helps. Dampen the area to a saturated-surface-dry condition—pre-wetting improves bond and reduces suction—then remove standing water.
• Mix tiny batches. I can’t stress this enough. Working time is a couple of minutes at best. I use a small mixing cup or gloved hand and aim for a putty-like consistency that I can form into a firm plug. Warm water will shorten your time; cold water buys you a few extra seconds.
• Gloves are a must. Hydraulic cement is caustic, and this mix warms as it sets. Nitrile or rubber gloves give you dexterity and protect your skin.

Application and performance

For active leaks, I’ll form a plug, press it firmly into the recess, and hold it with steady pressure. You’ll feel it stiffen and heat up; after about a minute, it’s rock-solid and water is stopped. For damp but not actively flowing areas, I trowel the mix in and compact it, finishing with a slightly proud surface that I can shave back once it’s firm.

What stands out is how decisively it takes hold. There’s no sag, no washout, and the slight expansion during set helps the seal. It’s not a pretty finish—expect utility-grade gray—but it bonds well, even in damp conditions, provided the surface is properly prepared. In my use, patches stayed tight and dry through heavy rain and pressure changes that had defeated paints and elastomeric caulks.

Use cases that make sense

• Basement cove joint leaks (where the wall meets the slab)
• Tie-rod holes and honeycombing in poured walls
• Pipe penetrations through block or concrete
• Pool skimmer throats and returns (above and below waterline, with proper prep)
• Patching small masonry cracks that seep under pressure

A 10-pound pail goes a surprisingly long way for pinholes and narrow joints, but larger voids will consume material quickly. If you’re parging or trying to cover larger areas, this is the wrong product—use it as a targeted leak-stopper, not a general resurfacer.

What I liked

• Truly fast, reliable set. Once mixed, it plugs and locks in minutes.
• Works in damp conditions and against light running water without washing out.
• Slight expansion during set improves mechanical seal in keyed joints.
• Versatile around foundations, pools, and pipe penetrations—one product for many water-prone spots.
• Handy 10-pound size for homeowners and pros tackling small to mid-size leak repairs.

What could be better

• The speed that makes it great also makes it unforgiving. There’s virtually no open time, so beginners may waste a batch or two learning the pace.
• The inner bag packaging keeps the powder fresh, but it’s inconvenient when you’re scooping small quantities.
• Not for flexible or moving joints. If the crack is actively shifting (expansion joints, structural movement), this rigid patch may re-crack.
• Finish aesthetics are basic. Plan to overcoat with a waterproofing paint or skim if appearance matters.

Tips for success

• Undercut the repair area. A keyed recess dramatically improves long-term hold versus smearing on a surface patch.
• Work in small, repeatable batches. I mix just enough for one plug or one short section—think golf-ball size, not trowel loads.
• Cool water extends working time slightly; warm water speeds it up. Adjust based on your conditions.
• Dampen the substrate first, but remove standing water unless you’re forming a plug against active flow.
• Press and hold. Mechanical pressure for 30–60 seconds is the difference between a true plug and a crumbly patch.
• If appearance matters, knock down high spots with a trowel as the mix transitions from plastic to firm. You can overcoat after it’s fully hard and dry.

Safety and cleanup

Wear gloves and eye protection. This is a caustic cementitious product that heats during hydration. Ventilation is wise in tight spaces. Clean tools immediately with water; once it sets, you’re done. Store the pail sealed, off the floor, and away from moisture—humidity will shorten shelf life.

Limitations and compatibility

• Don’t apply over paint, sealers, or loose/contaminated surfaces—bond will fail.
• Not a substitute for addressing bulk water management. If hydrostatic pressure is high, consider adding drainage, sump systems, or grading corrections after you’ve stopped the immediate leaks.
• Not intended for feather edging. It likes depth and confinement—use it to fill recesses, not to skim thin films.
• Temperature matters. Very hot or very cold conditions affect set time and performance; aim for moderate temperatures when possible.

Value and alternatives

Compared to generic patching compounds and masonry caulks, Quikrete Water-Stop is pricier per pound—but those products don’t reliably stop active leaks. In my experience, the cost is justified by the result: a one-and-done plug that doesn’t peel off under pressure. For large-area waterproofing, pair it with a dedicated masonry waterproofing coating once your spot repairs are complete.

Who it’s for

• Homeowners dealing with occasional seepage or sudden leaks in concrete or block.
• Property managers who need a quick, durable fix that tenants won’t wash out accidentally.
• Pool owners repairing small penetrations and skimmer leaks between service calls.
• Pros who want a reliable, shelf-stable leak-stopper for diagnostics and repairs.

Final recommendation

I recommend Quikrete Water-Stop for anyone who needs a fast, reliable way to plug water intrusion through concrete or masonry. It sets decisively in minutes, bonds well to properly prepared substrates, and stands up to damp conditions where other products fail. The learning curve is real—mix tiny batches, move with purpose, and prep thoroughly—but once you have the rhythm, it’s one of the most effective “stop the leak now” materials you can keep on hand. If you’re chasing moving structural cracks or want a pretty finish straight from the trowel, look elsewhere. For stubborn weeps, pipe penetrations, and cove joints under pressure, this is the right tool for the job.