Flat Slabs Ready for Finish Flooring with Ardex Self-Leveling
When a concrete slab sits out of tolerance, finish flooring cannot hide it. Ardex self-leveling underlayment corrects the slab plane so tile, plank, and polished finishes install on a true, flat substrate. We install as an Ardex-system contractor, bonding the SLU to your existing slab with the engineered primer and material sequence Ardex specifies.
A slab that is wavy, dished, or out of plane creates problems the finish flooring cannot solve. Tile will crack at grout joints. Plank will rock. Polished concrete will show every low spot. The slab tolerance has to be corrected before the finish goes down, and that is what Ardex self-leveling underlayment does.
The Ardex system starts with a bonded primer that locks the new pour to the existing concrete. Without this primer bond, the SLU will delaminate and fail. We follow Ardex spec exactly: prep the slab, apply the primer, mix and pour the SLU to the target flatness, and cure to the finish-flooring schedule. The result is a substrate ready for the next trade. See our full Ardex services if the project also needs overlay or repair work.
This approach differs from generic self-leveling products because the Ardex system is engineered as a complete assembly. The primer, the SLU chemistry, the cure schedule, and the finish-flooring compatibility all work together. We also coordinate with your polished concrete or tile installer to confirm the target tolerance before we pour, so the handoff is clean. For commercial projects, we integrate this into our broader commercial flooring scope.
Recent work
Installation sequence
How Ardex SLU Installation Unfolds
Measure and plan the pour
We laser-scan the slab to map high and low spots, calculate the SLU depth needed to hit the finish-flooring tolerance, and confirm the plan with the tile or plank installer before scheduling.
Prep and prime the slab
The slab surface is diamond-ground to Ardex profile, cleaned of dust and contaminants, and the Ardex primer is rolled across the entire area. This primer is the bond layer that keeps the SLU locked to the concrete.
Mix, pour, and gauge
Ardex SLU is mixed to the exact water ratio, poured across the floor, and gauge-raked to the target elevation. The material self-levels to a flat plane within its working window, so timing is critical.
Cure and hand off
The SLU cures on the Ardex schedule. We verify the final flatness against the finish spec, and the slab is ready for the next trade to install tile, plank, or polish without delay.
Scheduling and specs
Planning SLU Installation with Your Trades
The best SLU projects are scheduled into the build sequence, not added as a last-minute fix. We work with the finish-flooring contractor (tile, plank, or polish specialist) to agree on the target flatness, the depth of SLU needed, and the cure timeline before we pour. This coordination prevents surprises and keeps the project moving.
If the finish goal is to leave the SLU as the visible floor itself (rather than as a substrate under tile), we spec a different Ardex product, such as a polishable or top-coated overlay. Coordinate with our Ardex overlay services for that path. For projects that also need crack repair or waterproofing, we integrate those into the broader Ardex scope.
Bonded primer, tolerance specs, depth ranges and coordination with finish trades.
Ardex offers SLU products that can feather to extremely thin edges (essentially a few mil) and pour up to substantial depths for major tolerance correction. Product choice depends on the tolerance and project; we spec from the Ardex range.
Yes, critically. The Ardex primer is what bonds the SLU to the existing concrete. Without it, the SLU delaminates over time. Skipping or substituting the primer voids the Ardex system warranty.
Sometimes, with the matched Ardex polishable or top-coated overlay product. Most projects use SLU as substrate for tile, plank, or another finish; using it as the finish itself requires a different product spec.
Foot traffic typically the same day or next; finish-flooring install usually waits longer for the SLU to cure and dry to the finish spec. The cure schedule is in the project handoff.
Cost depends on depth, area, and existing slab condition. We provide a written quote based on the actual project; budget guidance can be discussed during the assessment.
Client reviews
What Gatineau Clients Say About Ardex Self-Leveling
They prep with Ardex primer like the spec calls for, not a generic primer. SLU bonds properly, my tile install goes in on a flat substrate. The Ardex-system difference is real.
Z. T5
Tile Contractor, Gatineau
★★★★★
Coordinated the SLU pour with my schedule, agreed the target tolerance up front, hit it on the pour. My plank install ran without complaint. Trade coordination at its best.
Y. T5
Finish Floor Installer, Ottawa
★★★★★
Three different substrate areas with different tolerance issues, three different Ardex SLU products specced. Each one matched the conditions; the finish-flooring went over each cleanly.
Q. T5
GC, Barrhaven
★★★★★
Tight feather-edge work at door thresholds where standard SLU would not work. They used the right Ardex product, feather edge held, no telegraph through the finish.
X. T5
Custom Home Builder, Nepean
From the blog
Concrete Guides & Articles
Practical reading on planning, finishes and caring for concrete in Gatineau.
Describe the slab area, the finish flooring planned, and the tolerance target, and we will spec the right Ardex SLU product and send a written quote within one business day.
