Slab Leveling Prep
in Gilbert.

Slab Leveling Prep is the pre-polish or pre-coating work that determines whether the final surface lasts. Pre-polish + pre-coat slab leveling using self-leveling underlayments and diamond planing. Brings dished, out-of-flat slabs back to a polish-ready datum.

Most polished concrete failures are prep failures. Skipped grinding, missed joint repair, untreated cracks, insufficient densification, every one of these shows up six months later as a worn surface, a delamination, or a polish that didn’t hold. Mint runs slab leveling as a standalone service for GCs and facility managers who want the prep done right before another contractor handles the finish, or as part of a full polished concrete or coating install.

Where slab leveling fits

• Out-of-flat slabs
• Pre-polish
• Pre-coating
• Tenant improvement
• Renovation

What we bring to a slab leveling job

Planetary diamond grinders, walk-behind and ride-on platforms for large slabs, HEPA-filtered dust collection for occupied buildings, PCD attachments for coating removal, semi-rigid polyurea for joint fill, polishable epoxy patch compounds, lithium-silicate densifier, the full slab-prep toolkit. Danny is on every job. No subcontractors.

If you need slab leveling done as a one-off before another contractor handles the finish, that’s standard scope. Request a walkthrough with the slab address.

How we find out how flat the slab actually is

Nobody can eyeball flatness. We walk the slab with a 10-foot straightedge and a laser, mark every low spot with crayon, and shoot elevations on a grid so there is a number attached to the problem instead of an opinion. On a tenant improvement in an older East Valley building we will usually find between a quarter inch and a full inch of deviation across a 10-foot span, and almost always it runs toward the floor drains, the old column footings, or wherever a previous owner saw-cut a trench for plumbing and patched it back with whatever was in the mixer that day.

That grid tells us which of two directions the job goes. If the slab is high in spots and generally sound, we plane it down with diamonds, which is faster, cheaper, and keeps you polishing the original slab with its original aggregate. If the slab is dished, if it’s got a bird bath in the middle of a retail floor where water pools every time the janitor mops, then grinding down to the low point would mean taking off an inch of good concrete across the whole room. That’s when we fill instead. Most of our jobs are some of both, and the crayon marks are what decide where the line falls.

Self-leveling underlayment is not a floor patch

Bagged floor patch from the home center and a real self-leveling underlayment are different products doing different work. SLU is a pumped, high-flow cementitious material that finds its own level and cures hard enough to polish. It wants a primed substrate, it wants the right water ratio measured by weight and not by eye, and it wants to go down in one continuous placement so you do not get a cold joint sitting in the middle of the room telegraphing through the finish.

Primer matters more than people think. A dry Arizona slab that has been sitting open in a shell building for two years will suck the water straight out of the underlayment before it has a chance to flow and level itself, and you end up with a rough, chalky surface that will not take a polish. We prime, we let the primer flash, and on especially thirsty slabs we prime twice. Then we mix in a barrel with a paddle at a controlled speed, because whipping air into the mix leaves pinholes that show up as little craters once the polisher opens the surface.

Moisture is the part that bites people here

Valley slabs get poured fast and covered fast. On new construction we run calcium chloride tests or relative humidity probes drilled into the slab and read at depth, because vapor drive coming up through a slab will lift a coating and will interfere with how a densifier reacts. Polished concrete is more forgiving than a coating on this front since it breathes, but if the plan is leveling now and a coating later, we need the moisture number before we spec the underlayment, not after.

Old slabs have the opposite problem. A 1980s warehouse slab in Mesa or Tempe was often poured on grade with no vapor barrier at all, and if there’s landscape irrigation running along that wall, you’ll see a permanent damp stripe eight feet into the building. We’ve seen crews level right over that and wonder why the finish went cloudy. If we find it, we tell you, and we spec a moisture-tolerant underlayment or a vapor mitigation layer before anything else goes down.

Curl, cracks, and the joints between

Slab edges lift as concrete dries from the top down, and in this climate they dry fast. Curl at a control joint means the two sides of that joint sit at different heights, sometimes by an eighth of an inch, which a forklift wheel finds every single pass and which reads as a shadow line under raking light in a showroom. We grind curl down at the joint edges rather than filling around it, because filling a lifted edge just gives you a thin feather of material that breaks off later.

Cracks get treated by width and movement. Hairline shrinkage cracks that are stable take a low-viscosity polyurea that wicks in and holds. Wider cracks with any vertical displacement get stitched, meaning we cut across the crack, set staples in epoxy, and then fill, so the two sides stop working against each other. Joints in a slab that will see wheeled traffic get filled full depth with semi-rigid polyurea and shaved flush, which is what protects the joint edge from spalling under a pallet jack.

Scheduling around heat and around your building

Underlayment sets faster when it’s hot, and in a shell building in July with no HVAC running, the interior can sit at 115 degrees. That cuts working time down to where a big pour stops being safe to place in one shot. We either start at four in the morning, get temporary cooling into the space, or split the placement into planned sections with a defined cold joint we can hide under a column line. What we will not do is add water to buy flow time, which weakens the material and shows up as a soft spot under the polisher.

For occupied buildings we section the work. A restaurant on Val Vista or a clinic in Chandler cannot shut the whole floor, so we barricade a zone, run everything under HEPA vacuums, level and cure that zone, and move. Diamond planing throws dust rather than fumes, which makes it easier to work around staff, but the containment still has to be real. Danny walks the space before quoting and marks the zones on the plan so you know exactly which days affect which part of your operation.

Once the slab is flat and sound, it’s ready for whatever comes next. That might be our own commercial polished concrete crew coming back in, it might be densification and a sealer, or it might be another trade’s coating system. We do the prep the same way either direction.