Fixing Out-of-Tolerance Slabs with Self-Leveling Concrete
A commercial slab that doesn't meet flatness spec becomes a finish-flooring problem. Gatineau Concrete applies self-leveling underlayment over the existing slab to correct elevation and bring the floor to the tolerance your tile, plank, polish or coating installer requires. The slab gets fixed first, so the finish goes down right. Free written estimate on every project.
Most Finish-Floor Problems Start with the Concrete Slab
Lippage in tile, gaps between planks, uneven coating sheen, inconsistent polish, these issues get blamed on the finish installer, but the real culprit is usually a slab that was poured outside the flatness tolerance for that particular finish. No finish installer can make a wavy slab look flat. The slab has to be flat first.
We diamond-grind the existing slab to bare concrete, apply a bonded primer that locks to the substrate, then pour self-leveling underlayment to the target depth. The material self-levels to a flat plane, cures to the finish-flooring spec, and the slab is ready for whatever finish comes next.
We survey the existing slab to find high and low spots, calculate the depth needed to reach the finish-flooring's tolerance, and confirm the plan with the finish-floor contractor before we start.
Grind and prepare
Diamond grinding removes the top layer of the slab, exposing clean concrete and removing old coatings or contaminants. A bonded primer is then applied to ensure the self-leveling material adheres fully.
Mix and pour
The self-leveling material is mixed to the manufacturer's water ratio, poured to the calculated depth, and gauge-raked to distribute it evenly. The material flows to a flat plane within minutes.
Cure and handoff
The pour cures on the manufacturer's schedule. We verify the final flatness against the finish-flooring spec and hand the slab back to the finish installer ready for tile, plank, polish or coating.
Coordination with finish trades
Self-Leveling Works Best When Scheduled Into the Build
The best results come when self-leveling is planned from the start, not added as an emergency fix. We coordinate with the tile, plank or polish installer to agree on the target flatness, confirm the depth needed, and schedule the pour into the build sequence.
On larger projects, we also coordinate with adjacent anti-slip flooring, epoxy systems in different zones, and any floor repair that needs to happen first. This kind of trade coordination prevents delays and ensures every finish goes down on a slab that meets spec.
Tolerance specs, primer systems, depth ranges and when to self-level before finishing.
Each finish has its own tolerance, large-format tile is more demanding than plank, polished concrete more than tile. The finish installer's spec defines the target; we pour self-leveling to meet that target, and we will get the spec from your finish-flooring trade up front.
Yes, modern self-leveling systems can be poured at a thin overlay depth for minor tolerance corrections, up to several inches for major fixes. The system spec changes with depth; we use the right one for the pour.
Always. The primer is what bonds the new pour to the existing slab; without it, the self-leveling delaminates over time. We use the manufacturer-matched primer for the system, applied to a diamond-ground substrate.
Foot traffic typically within hours, but finish flooring usually waits longer for the pour to cure and dry. We give the finish-flooring trade the cure timeline so they can schedule their install.
Cost and disruption. A self-leveling overlay corrects the existing slab without tear-out, in a fraction of the time and budget. Where the existing slab is structurally failing rather than just out-of-tolerance, a new slab is the right call; we will tell you which case yours is.
Client reviews
What Gatineau Operations Say About Their Self-Leveling Pours
Tile contractor had refused to install on our out-of-tolerance slab. Self-leveling pour brought it to spec inside three days; tile install went perfectly after that. Fixed the actual problem.
W. V.
Construction Manager, Gatineau
★★★★★
Coordinated with our polished-concrete trade from day one. Target tolerance agreed, pour hit it, polish came out flawless. Real trade coordination, not just a contractor.
Z. V.
Retail Build-Out Director, Ottawa
★★★★★
Existing slab had two inches of variation across the floor. Self-leveling brought it flat, finish coating installer was thrilled. Cost a fraction of a new slab pour.
Y. V.
Property Manager, Barrhaven
★★★★★
They were honest that part of our slab needed structural repair, not just self-leveling. Did both in sequence. The honesty was worth the slightly bigger scope.
Q. X.
Healthcare Facility Director, Nepean
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Practical reading on planning, finishes and caring for concrete in Gatineau.
Tell us the floor area, the target finish flooring and its tolerance spec, and we will assess the existing slab and quote the self-leveling pour in writing.
