New concrete does not naturally stick to old concrete — pour a fresh topping over a cured slab and it will delaminate, curl, and flake off within a season or two. Quikrete Concrete Bonding Adhesive exists to solve exactly that problem. It’s a milky, low-VOC acrylic emulsion that you brush or roll onto existing concrete so that new toppings, patches, stucco, and plaster grab hold and stay put, without the traditional step of mechanically roughing the surface. At about $25 to $35 per gallon, it’s one of the cheapest insurance policies in masonry repair. Here’s what it does well, where it fails, and how to apply it so your patch outlives the slab around it.
What Quikrete Concrete Bonding Adhesive Is
The product (Quikrete No. 9902) is a water-based acrylic resin emulsion — essentially a tough, re-emulsifiable latex that penetrates the pores of cured concrete and creates a tacky, chemically receptive layer. When fresh cement-based material is applied over it, the acrylic film keys into both surfaces and forms a bond stronger than the mechanical grip fresh concrete could ever get on smooth, cured cement paste.
It comes in quart ($10-$14), gallon ($25-$35), and 5-gallon ($95-$120) sizes at Home Depot, Lowe’s, and most hardware stores. Coverage runs 200 to 400 square feet per gallon as a bonding coat, depending on how porous the surface is — old broom-finished exterior concrete drinks more than steel-troweled interior slabs. The formula is non-flammable, cleans up with soap and water while wet, and can be used indoors without ventilation drama, which is more than you can say for solvent-based epoxy bonders.
Where to Use It
Quikrete lists the product for bonding new concrete, mortar, stucco, and plaster to existing surfaces. In practice, the jobs where it earns its keep are:
- Resurfacing and toppings: bonding a 1/2 inch to 2 inch concrete overlay to a worn slab, step, or porch cap
- Patching: priming spalled areas, chipped step edges, and divots before filling with sand mix or patching compound
- Stucco and plaster: as a bonder on masonry, brick, or old stucco before a new coat — a standard move on remodels
- Setting beds: priming concrete before a mortar bed for tile or stone in exterior applications
- Fortifying mixes: diluted 1:1 with water, it can replace part of the mix water in sand mix or stucco to boost adhesion and flexibility
That last use is worth underlining. Adding the adhesive into a patch mix — rather than only under it — gives thin repairs the polymer modification they need to resist shrinkage cracking. For feather-edge repairs under 1/2 inch, a fortified mix over a primed surface is the difference between a patch that lasts ten years and one that pops out next winter.
Where Not to Use It
Re-emulsifiable acrylics have a known weakness: constant water exposure. Because the cured film can soften if it stays saturated, this adhesive is the wrong choice for the inside of ponds, pools, and fountains, for surfaces with active hydrostatic pressure like leaking basement walls, or under slabs that sit in standing water. For permanently wet conditions, step up to an epoxy bonding agent such as Sikadur 32 or use a non-re-emulsifiable SBR latex specified for immersion.
Skip it, too, on painted or sealed concrete — the adhesive bonds to what it touches, and if it’s touching a failing paint film, your new topping is only as strong as that old paint. Strip sealers and coatings first, or grind down to bare concrete. And don’t treat it as a structural adhesive for gluing dry objects together; it’s a bonding primer for fresh cementitious material, not a construction adhesive like PL Premium.
Surface Prep Still Matters
The marketing points out that the adhesive “eliminates the need for roughing the surface,” and that’s true — but it doesn’t eliminate the need for a clean surface. Bond failures with this product trace back to dust, oil, and curing compounds far more often than to the adhesive itself. Prep sequence that works:
- Scrape off loose, flaking concrete and sweep thoroughly
- Degrease oil spots with a concrete degreaser or TSP solution — driveways and garage slabs almost always need this
- Pressure-wash at 3,000 PSI or scrub and rinse, then let the surface dry. Damp is acceptable; puddled is not
- Check for sealers by sprinkling water — if it beads instead of soaking in, grind or strip before bonding
On old, polished-smooth interior slabs, a quick pass with a 30-grit diamond cup wheel is still cheap insurance even though the label says you can skip it. Every bit of profile you add multiplies the mechanical grip working alongside the chemical bond.
How to Apply It, Step by Step
Application is genuinely simple, which is why the failures are almost always timing mistakes rather than technique mistakes. Stir the adhesive — don’t shake it into a foam — and apply a uniform coat with a brush, 3/8-inch nap roller, or airless sprayer. Work it into pores rather than flooding it on; a thick puddled film is weaker than a thin, well-wetted one.
Then comes the decision that determines whether your repair holds: when to place the new material. Quikrete gives you two windows. For most patching and topping work, let the adhesive dry until it turns from milky white to clear and tacky — typically 1 to 3 hours at 70°F, longer in cool or humid weather — then apply your concrete, mortar, or stucco. The tacky-clear stage is the sweet spot. Alternatively, for same-session work you can place fresh material into the wet adhesive, but never let the film fully cure unused: if it sits more than about 24 hours without being topped, dust settles on it and you should recoat. Apply only when surface and air temperatures will stay above 50°F for 24 hours, and protect the work from rain until the topping has set.
Performance, Dry Times, and Coverage
At 70°F and moderate humidity, expect the film to be tack-dry in about an hour and ready for topping shortly after. Full cure of the bonded assembly follows the concrete’s own schedule — foot traffic on a bonded topping in 24 to 48 hours, full strength at 28 days like any cement product. Cold weather stretches everything; at 50°F, drying can take 3 to 4 hours and you should double your protection time.
Plan quantities generously. One gallon covers roughly 200 square feet on porous broom-finish concrete and up to 400 on dense surfaces; used as a 1:1 diluted fortifier in the mix, a gallon treats about two 60-pound bags of sand mix. For a typical 4 x 8 foot porch resurface, a single quart handles the priming with margin to spare. Store leftovers sealed and above freezing — the emulsion is ruined if it freezes in the garage over winter.
Quikrete Bonding Adhesive vs the Alternatives
How does it stack up against other bonders on the shelf? Against a scrub coat (a slurry of cement and water brushed into the surface), the acrylic wins on convenience and forgiving open time, though a well-executed scrub coat immediately ahead of the pour is still what many DOT specs call for on structural repairs. Against SBR latex bonders like Sika Latex R, performance is comparable for general work, with SBR products usually rated better for damp service. Against epoxy bonding agents, there’s no contest on strength — epoxy bonds at 2,000+ PSI versus a few hundred for acrylics — but epoxies cost four times as much, have short working windows, and are overkill for a step patch or porch topping.
For the homeowner and remodeler jobs this product is aimed at — patches, toppings, stucco prep, small resurfacing work in normal exposure — Quikrete Concrete Bonding Adhesive hits the right balance of price, forgiveness, and performance. Clean the surface like the bond depends on it (it does), catch the adhesive at its tacky stage, keep it out of permanently wet service, and your new concrete will still be holding tight when the surrounding slab needs its next repair.
