Every room in a building has a single reference datum level from which all floor finishes are set out, and the flooring gang's first job is to snap a level line at this datum on the walls before a single tile is laid. Skipping this and just following the concrete slab's natural level will almost always produce a floor that visibly slopes or steps between rooms, something an owner notices the very first day they walk the finished flat.
The screed bed below the tile, usually a sand-cement layer, is what actually carries the level correction, and it needs to be properly compacted and cured, not just thrown down loosely — a soft or hollow screed is the single biggest cause of tiles cracking or drumming later. Vitrified tiles are the common choice for living areas because of their low water absorption and consistent finish, ceramic tiles remain popular for walls and lighter-duty floors, and granite or natural stone is used where higher durability and a premium look are wanted, though it needs sealing against staining. In wet areas the floor must carry a slope towards the drain even after tiling is complete, and tile spacers of about 2-3 mm keep joints uniform and allow for grout without creating lippage, the ugly and trip-prone condition where adjacent tile edges sit at different heights.
Skirting should be laid with a straight, continuous line at the floor-wall junction, mitred neatly at corners, and after the flooring is done and the adhesive has cured, every tile should be gently tapped with a wooden or rubber mallet handle to listen for a hollow sound — a hollow-tap sound means poor bonding underneath and that tile needs to be relaid before the owner moves in, not after.
Tile spacer gap
2-3 mm
Wet area floor slope
Towards drain, gentle
Check method for bonding
Hollow-tap test
Remember on site
- Always set out flooring from a snapped datum level, not from the raw slab level
- A well-compacted, cured screed prevents hollow or cracked tiles later
- Hollow-tap every tile after laying to catch poor bonding before handover
Check yourself
Why must a datum level be snapped on walls before flooring starts?
What is the main risk of a poorly compacted or uncured screed bed?
Why are vitrified tiles commonly preferred for living area floors?
What is 'lippage' in tile flooring?
What gap do tile spacers typically maintain between tiles?
What should be checked after tiling and curing, before handover?
In wet areas, what must the floor slope achieve even after tiling?
Why does granite or natural stone flooring need sealing?
What is the purpose of skirting at the floor-wall junction?
Which flooring material is generally chosen for lighter-duty use and wall cladding?
What causes tiles to sound hollow when tapped?
What is the consequence of ignoring the datum level and simply following the raw slab surface for flooring?