MOISTURE AND LEVELLING CHECKS BEFORE COMMERCIAL FLOOR TILING
A floor that appears dry and level enough may still be unsuitable for the proposed tiling system. Different screeds, concrete backgrounds, repairs and levelling products require project-specific checks before fixing proceeds.
Technical note: This is general project-planning guidance, not a specification or design approval. Check the current project documents, applicable standards and system manufacturers' instructions.
Identify the screed or background
Record the floor construction, age, thickness where known, surface condition, existing finishes and any heating system. Cementitious, calcium sulphate and proprietary screeds have different preparation and moisture requirements; using a generic drying assumption risks delays and failures.
Agree moisture testing responsibility
Confirm the specified testing method, thresholds and who is authorised to accept the result. Check the installation-system and manufacturer requirements. Visible dryness and calendar age are not substitutes for the appropriate assessment, and a damp-proof strategy should be agreed with the relevant designer where needed.
Survey levels and required tolerances
Determine the finished floor level, threshold heights, tile dimensions and permitted flatness before selecting a levelling system. Local hollows and large-area deviations may require different approaches. Do not rely on a thick adhesive bed to correct an unsuitable floor unless the approved system permits it.
Match levelling products to the job
Check substrate strength, contamination, primer requirements, permissible thicknesses, moisture compatibility and proposed tile adhesive. Allow for mechanical preparation where required. Product choice should follow the approved technical system, not be based only on how many bags cover the area.
Document readiness and handover
Track survey findings, corrective works, product details, curing windows and relevant inspections. Agree when areas become available for tiling and when other trades can regain access. Record defects or additional work through the contractual process before proceeding.
The key takeaway
Moisture and level issues are programme and design risks that should be resolved at the substrate handover, not discovered after tiles are installed.
Relevant service: Commercial substrate preparation · All technical guidance
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