Professional Subfloor Leveling and Floor Preparation

Uneven floors are more than a cosmetic problem — they cause your new flooring to crack, develop gaps, squeak, and wear out years before it should. Zona Floors provides professional subfloor leveling and preparation services that give your new floors the flat, stable foundation they need to perform and last.

Why Subfloor Leveling Matters

Think of the subfloor as the foundation for your flooring. Just as a house needs a level foundation, every flooring material needs a flat, stable substrate:

• Tile cracks over dips and rocks on high spots. Large-format tiles are especially unforgiving — even small deviations cause lippage (one tile edge sitting higher than its neighbor)
• LVP and laminate planks separate at click-lock joints over uneven areas, creating visible gaps that collect dirt and moisture
• Hardwood develops squeaks as boards flex over voids in the subfloor
• Carpet shows every bump and depression through the surface

Flooring manufacturers require the subfloor to meet specific floor flatness tolerances — typically no more than 3/16 inch deviation over a 10-foot span. Installing flooring over a subfloor that exceeds these tolerances voids the material warranty and leads to premature failure. For a deeper look at what goes into this step and why it cannot be skipped, see our article on subfloor leveling and why floor prep matters.

Common Subfloor Issues in Arizona

Arizona homes present specific subfloor challenges:

Concrete Slab Settling

Most Arizona homes are built on concrete slab foundations. Over time, the desert soil beneath the slab can shift, causing the concrete to settle unevenly. This creates dips, high spots, and sometimes hairline cracks across the slab surface. Self-leveling compound is the standard solution for concrete slab unevenness.

Old Adhesive Buildup

When old tile, vinyl, or carpet is removed, the adhesive used to secure it often remains on the subfloor. This dried adhesive creates an uneven surface that prevents new flooring from sitting flat. We remove old adhesive using dust-free grinders and scrapers to restore a clean, flat surface.

Plywood Subfloor Issues

Second-story and some older Arizona homes have plywood subfloors rather than concrete slabs. Plywood can develop waves, squeaks, and soft spots from moisture exposure, age, or poor original installation. We repair damaged sections, screw down loose areas, and install plywood overlay when needed.

Moisture Concerns

While Arizona is dry above ground, slab foundations can absorb moisture from the soil through capillary action. This moisture can interfere with flooring adhesives and damage sensitive materials. We perform moisture testing using calcium chloride (ASTM F1869) or relative humidity probe (ASTM F2170) methods to determine if a moisture barrier is needed before installation.

Leveling Methods

Self-Leveling Compound

Self-leveling compound (SLC) is a cement-based product mixed to a pourable consistency. When poured onto the subfloor, it flows into low spots and self-levels to create a flat surface. SLC is ideal for:

• Concrete slab corrections (dips, settling, minor cracks)
• Preparing for tile, LVP, or hardwood installation
• Covering large areas efficiently

SLC typically cures within 24 hours, and most products can accept flooring installation after 24-48 hours.

Plywood Overlay

For wood subfloors with significant issues, a plywood overlay provides a fresh, flat surface. We install 1/4-inch or 1/2-inch plywood over the existing subfloor, screwing it down in a grid pattern to create a stable platform for new flooring.

Grinding and Scarifying

High spots on concrete can be reduced using floor grinders. We use dust-free grinding equipment with attached vacuums to minimize dust. Grinding is also used to remove old adhesive, paint, and coatings.

Part of a Bigger Project

Subfloor preparation is included with all of our flooring installation projects at no additional charge for standard prep work. For extensive leveling or repair, we provide a detailed estimate. If you are getting new flooring and suspect your subfloor may need work, mention it when you schedule your estimate — we assess the subfloor during every consultation visit.

Call 480-428-5080 or contact us online for a free subfloor assessment.