Slab Flatness Correction with Ardex Self-Leveling in Laval
When a concrete slab sits outside tolerance, finish flooring cannot hide it. Ardex self-leveling underlayment corrects the slab plane so tile, plank, and polish install on a true substrate. We apply the bonded primer system and pour to spec, coordinating with your finish trade from the start.
A slab that is wavy, dished, or out of plane cannot be fixed by the finish flooring itself. Tile will crack at grout joints, plank will rock, polish will show every low spot. The slab tolerance must be corrected before the finish goes down, and that is what Ardex self-leveling underlayment does.
We install as an Ardex-system contractor, which means the primer, the SLU product, the mix ratio, and the cure schedule all follow Ardex specification. The bonded primer is the critical step; it locks the new pour to the existing concrete so the two work as one. Skip the primer or use a generic substitute, and the SLU will delaminate within months.
The work fits into the build sequence before the finish trade arrives. We coordinate the target flatness with the tile, plank, or polish installer, measure the slab, calculate the pour depth, and deliver a substrate ready for the next phase. See our Ardex waterproofing service if the project also needs below-grade protection, and explore our full Ardex range for overlay and repair options.
Recent work
Installation sequence
Ardex SLU Installation in Laval
Laser-level the slab
We scan the existing slab with laser level, record elevation at grid points, identify high and low spots, and calculate the SLU depth needed to bring the slab into the finish-flooring tolerance band.
Grind and prep surface
The slab is diamond-ground to Ardex profile, dust and contaminants removed, and the surface inspected for cracks or spalls that need repair before the primer coat.
Apply Ardex primer
The matched Ardex primer is rolled across the prepped slab. This is the bond layer; it ensures the SLU adheres permanently to the concrete below. No primer, no warranty.
Pour and level SLU
Ardex SLU is mixed to the exact water ratio, poured across the floor, and allowed to self-level to a flat plane. The material has a working window; we move quickly to use it within spec.
Cure and handoff
The pour cures on the Ardex schedule. We confirm final flatness against the finish-flooring spec and hand the slab off ready for tile, plank, or polish installation.
Build sequence
Timing Self-Leveling Into the Project
The best results come when Ardex SLU is scheduled as part of the build plan, not added as an emergency fix after the slab is already in place. We work with the finish-flooring contractor to agree the target flatness, the acceptable tolerance band, and the pour depth needed to hit that target.
Foot traffic can resume the same day or next, but the finish flooring usually waits for the SLU to cure fully and dry to the finish spec. The cure schedule is documented in the project handoff so the next trade knows when to start. Coordinate with our Ardex overlay service if the SLU will be left as the finished floor itself, and with our Ardex repair service if the slab has damage that needs fixing before the SLU goes down.
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.
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, Laval
★★★★★
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, Montreal
★★★★★
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, Terrebonne
★★★★★
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, Longueuil
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