Flooring Technical Guides
Subfloor Preparation Before New Flooring
Make substrate readiness a recorded part of the installation scope rather than an assumed extra.
Inspect what will support the new floor
Identify the substrate and any existing covering, adhesive or preparation layer. Record loose areas, cracks, surface irregularity and known moisture concerns. Ask what can be inspected now and what will only become visible after removal.
A proposal prepared from photographs may be useful for initial budgeting, but it should identify its assumptions. Agree who will assess hidden conditions and approve additional work before installation proceeds.
Obtain product-specific acceptance criteria
Request the installation guide for the selected covering and the instructions for related preparation and fixing products. Compare the required checks against the actual base. Do not apply one flatness or moisture number to all materials.
Quick-Step provides installation resources for its vinyl systems, while Interface documents substrate requirements for its own carpets. These examples show where to obtain criteria; they do not establish readiness for an unrelated product.
Separate flatness from level
Level describes orientation relative to horizontal. Flatness concerns variation across the surface. Ask the installer which requirement applies, how it will be checked and where readings will be recorded. A surface can satisfy one question while still needing attention for the other.
Discuss doorway heights and adjoining floors alongside the assessment. Preparation decisions may alter the final build-up, so finishes and transitions should be coordinated before quantities are confirmed.
Write a preparation schedule
| Work item | Clarify in the quotation |
|---|---|
| Existing finish | Removal, retained layers and disposal. |
| Surface condition | Loose areas, contamination and old residues. |
| Repairs and smoothing | Location, proposed system and assessment basis. |
| Moisture-related work | Findings, specified treatment and compatibility. |
| Readiness | Who inspects, records and accepts the prepared base. |
Check the sequence and compatibility
Ask how repairs, primers, smoothing materials and the fixing system will work together. Obtain the relevant product instructions and the required waiting or readiness conditions. A programme should allow those conditions to be met rather than assuming every layer is ready the same day.
Keep unknown damp or a suspected leak as an investigation item. Preparation should respond to the identified conditions. Continue with the separate moisture guide.
Record acceptance before covering
Keep the agreed assessment, preparation scope, relevant photographs and sign-off with the project folder. Identify limitations in the record, including inaccessible areas or work awaiting confirmation.
Where additional preparation is needed, approve the revised method, cost and programme before proceeding. The handover checklist explains which records to retain after the visible floor is complete.
Sources and product instructions
Primary resources checked on 11 October 2026. Manufacturer examples apply to their own systems; obtain current instructions for the product supplied to your project.
Independent editorial guidance. Check the current documents for the exact product and project.
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