When Slabs Need Flattening, Ardex Self-Leveling Underlayment Fixes It
Tile, plank, and polish installers need a flat substrate. When the existing slab falls short of tolerance, Ardex self-leveling underlayment brings it into spec. We install as an Ardex-system contractor, bonding the primer and pour to the concrete below so the finish flooring sits on a stable, flat base. Free written estimate.
A slab that looks flat to the eye may still be out of tolerance for finish flooring. Tile grout lines telegraph the bumps. Plank flooring rocks on high spots. Polished concrete shows every dip. The finish installer cannot fix a bad slab; the slab has to be right before the finish goes down.
Ardex self-leveling underlayment is the engineered solution. The bonded primer creates a permanent mechanical lock between the new pour and the existing concrete. The self-leveling chemistry flows to a flat plane, then cures to the tolerance the finish flooring spec requires. We install it as an Ardex-system contractor, meaning every step follows Ardex protocol.
Pair this with our Ardex waterproofing if the slab sits below grade, or with Ardex overlay systems if the goal is a finished decorative surface. All three work together in the Ardex ecosystem.
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Installation sequence
The Ardex SLU Process in Detroit
Laser-scan the slab
We measure the existing slab elevation across the entire floor area, identify high and low spots, and calculate the depth of Ardex SLU needed to bring the surface into the finish-flooring tolerance spec.
Prep and prime
The slab is diamond-ground to Ardex profile, cleaned of dust and contaminants, and the Ardex primer is applied. This primer is the bond layer; it ensures the SLU adheres permanently to the concrete below.
Pour and self-level
Ardex SLU is mixed to the exact water ratio, poured across the primed slab, and allowed to flow to a flat plane. The material has a working window; we move quickly to use it within spec.
Cure and verify
The pour cures on the Ardex schedule. Once cured, we verify the final flatness against the finish-flooring spec and hand off the slab to the tile, plank, or polish installer.
Scheduling and specs
Coordinating Self-Leveling With Your Finish Trade
The best SLU projects are planned, not emergency fixes. We coordinate with the finish-flooring contractor before the pour, agree on the target tolerance, and schedule the SLU pour to fit the build sequence. This way, the finish installer arrives to a slab that meets their spec.
If the project also includes Ardex repair work or Ardex certified installation elsewhere on the site, we integrate the SLU into the broader Ardex scope. One contractor, one system, one warranty.
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 Detroit 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, Detroit
★★★★★
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, Warren
★★★★★
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, Ann Arbor
★★★★★
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, Sterling Heights
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