Concrete Subfloor Prep in Atlanta: Flatness, Moisture & LVP

Concrete is common throughout Metro Atlanta, but not every slab is ready to receive finish flooring. Preparation requirements depend on the flooring and installation system being used.

Flatness

Use the flooring manufacturer's current tolerance. Low areas, ridges, joints, prior patching and abrupt transitions can telegraph through resilient flooring or affect locking systems and hardwood installation.

Moisture

There is no single universal concrete moisture percentage that applies to every flooring product. Test using the method required by the flooring, adhesive or moisture-control manufacturer and compare the result with that system's published limits.

Surface condition

Adhesive residue, curing compounds, paint, contaminants, weak patching and laitance can interfere with bonding. A glue-down system may require mechanical preparation or approved primers and patching materials.

Level vs. flat

A floor does not always need to be perfectly level to receive flooring, but it does need to meet the required flatness and stability criteria. Correcting a local dip is different from changing the elevation of an entire room.

Moisture-control products

Primers, vapor-retarding systems and moisture-mitigation coatings are product-specific. Selection should follow test results, the flooring system and the manufacturer's compatibility requirements.

Why this matters

Preparation is less visible than the finished plank, but it is the part of the project most likely to affect movement, hollow spots, locking performance and transitions later.

Why can a new floor move, sound hollow or show unevenness?

The finish floor depends on the substrate beneath it. A low spot, ridge, weak patch or unsuitable bonding surface can affect the completed installation. The symptom alone does not identify the cause: a hollow sound, for example, requires evaluation of the product, installation method and actual site conditions.

For an Atlanta basement, a Sandy Springs condominium or a Roswell commercial suite, begin with the substrate and product documents. Do not assume a thicker plank or extra pad will correct a slab that falls outside the specified requirements.

What should be measured before flooring is ordered?

Document the room sizes, existing floor heights, transitions and areas needing closer inspection. Check the substrate against the chosen product's flatness criteria using the required method. Record moisture testing in the form required by the flooring and installation-system manufacturer.

Ask how results are documented and what happens if they fall outside the permitted range. A statement that the slab “looks dry” is not a substitute for required testing. Likewise, there is no universal moisture-meter percentage that proves every concrete floor is ready for every adhesive.

Can new LVP cover old adhesive or paint?

That decision depends on the existing material and the new system. Adhesive residue, paint, curing compounds and other coatings can interfere with bonding or preparation products. Before disturbing an unidentified old floor covering or residue, have the material evaluated and the appropriate removal approach determined.

Avoid applying a new patch or adhesive over an unknown surface simply to hide it. The proposal should identify the preparation method and any primer or compatible system being specified. Manufacturer approval is especially important when several preparation and installation products are combined.

Does the whole floor need to be leveled?

Flat and level describe different conditions. A floor can slope while still being flat enough for a particular product; it can also be level overall yet have local dips or ridges. Correcting a local irregularity is a different scope from raising an entire room.

Discuss the finished elevations at doors, kitchen appliances, bathrooms, stairs and adjoining flooring. Changing an elevation can create consequences elsewhere. Ask the contractor to explain the measured problem and proposed correction before treating “leveling” as a single standard service.

How does the plan change between floating and glue-down flooring?

A floating system still needs the specified substrate condition, clearances and permitted underlayment. Extra cushioning is not an automatic improvement. A glue-down installation additionally depends on the bond between the prepared substrate, adhesive and flooring.

The floating versus glue-down guide explains the selection questions. Use the instructions for the actual product—including the exact COREtec, Shaw, Mohawk, Mannington or other collection under consideration. Brand reputation does not override collection-specific requirements.

What belongs in a preparation allowance?

Separate removal, surface preparation, patching, height transitions and any specified moisture-control system from the finish-floor material. If the substrate cannot be fully evaluated until demolition, set a written process for documenting findings and approving added work.

Keep photos, measurements and the product information with the completed job record. This makes the preparation decision understandable when comparing estimates and useful if questions arise later. For a measured evaluation, visit Final Floors' subfloor repair and leveling service.

Updated September 11, 2026: added testing questions, existing-residue considerations, elevation planning and estimate documentation.