Guide
How to Prepare a Subfloor for Laminate Flooring
A laminate subfloor should be sound, dry, clean and sufficiently flat for the chosen system. Underlayment is part of the system, not a substitute for preparation.
Prepare the subfloor before choosing underlayment or opening the laminate packs. Remove loose material, correct flexing and visible level changes, confirm that moisture is not trapped and check the perimeter and door transitions. Exact limits depend on the flooring, underlayment and subfloor construction.
Work through the checks in order
- Strength: remove or repair powdery areas, loose coatings and debonded patches.
- Flatness: use a long straightedge to find high spots, dips and deflection in several directions.
- Dryness: rule out fresh wet layers, leaks and condensation; use the material instructions for readiness.
- Cleanliness: vacuum the surface and remove stones, crumbs and dried mortar.
- Transitions: check door clearances, thresholds, pipes and room edges where the floating floor must remain free to move.
Concrete and cement-based subfloors
Remove weak areas and level changes, then let repair and levelling layers reach the condition specified by their manufacturers. Do not cover a floor that still contains construction moisture or an unresolved leak. Floor-area, screed and self-leveling calculators can help estimate material quantities after the system is selected.
Wooden subfloors
Inspect boards, sheet joints, fixings and flex. Repair movement and squeaks in the structure first. Laminate should not be used to clamp weak boards together or hide water damage.
Underlayment and final cleaning
Choose underlayment after assessing the subfloor and reading the collection requirements. Lay it without folds or unintended overlaps, and clean the surface immediately before installation. Its type does not remove the need for perimeter gaps.
Before laying the first plank
- Confirm row direction, door heights and transitions.
- Plan the layout so the last row is not an unexpectedly narrow strip.
- Check that the material and subfloor suit the room conditions.
- Keep service access where it is needed and do not trap the floating floor with fixed elements.
Frequently asked questions
Can laminate be installed immediately after a floor is poured?
There is no universal waiting period. Confirm the readiness required by the covering and levelling product manufacturers.
Does every subfloor need primer before laminate?
No. Primer depends on the surface and any later levelling work; it does not replace cleaning or repairing weak areas.
Can small debris remain under the underlayment?
No. Point debris creates local flexing, noise and stress at the locking joints.
Should furniture area be subtracted from the order?
Only when it will remain permanently uncovered. Counting the intended floor area is safer if the room may be rearranged.