A floor tiling job has a personality trait: it rewards patience before the first tile and punishes improvisation after. The layout decision you make in twenty minutes of dry-laying determines whether your room has a balanced border or a sliver of cut tile sneaking along one wall for the rest of its life.
This guide covers floor tiling from the subfloor up: substrate preparation and level checking, the layout and setting-out that professionals mark before mixing adhesive, adhesive selection and notch technique, spacing, leveling systems, and the curing and grouting sequence that makes a floor survive decades of foot traffic.
Stage One: Preparing the Subfloor
The floor beneath decides the floor above. Every hour of tile work assumes the layer under it is sound, flat, cured, and dry, and the fastest way to waste good tiles is to lay them over a subfloor that isn't.
Test for soundness. Scratch the screed surface with a screw or key: a light scratch that powders slightly is normal; a surface that crumbles, dusts heavily, or shows loose patches needs remedying first. Tap across any old floor you are tiling over, hollow spots mean the old layer has debonded and will take the new one with it. Repair or remove before proceeding.
Check for level, in both senses. A 1.5–2 m spirit level in a grid pattern across the room reveals two different defects: local undulations (a slab with humps and dips) and overall tilt (a room that drains gently toward one corner). Local undulations beyond about 3 mm per 2 m will telegraph through standard tiles as lippage; correct with a levelling compound, which self-flows and flattens without needing a screed's thickness. Overall tilt is only a defect if the room needs to drain, in a bathroom, verify the fall runs to the drain at roughly 1:100; in a living room, gentle tilt can be accepted if the tile layout can be squared to itself.
Respect moisture and cure. Fresh sand-and-cement screed needs a minimum of 7 days cure before tiling (28 for a conservative specification), and the room's own slab must be older than that. Tiling a screed that still holds moisture traps that moisture under an impermeable floor, it has to go somewhere, and it pushes at the adhesive bond. On damp-prone ground-floor slabs, a damp-proof membrane is the correct answer, not hope.
Sweep, vacuum, prime. The final act of preparation is a clean, dust-free surface, primed if the adhesive's data sheet calls for it. Primer is inexpensive and measurably improves bond on absorbent screeds; skipping it to save twenty minutes of drying is a poor trade against a floor's twenty years.
Stage Two: Setting Out: The Half Hour That Decides the Room
Setting out is the professional's answer to the most common tiling question: where do I start? The methodical version:
Find the room's true geometry. Measure the four walls. They are not equal in pairs, and the corners are not square, accept this early. Strike two reference lines through the room's centre using the 3-4-5 method to guarantee perpendicularity: measure 3 units along one line, 4 units along the perpendicular from the same corner point, and adjust until the diagonal between the ends measures exactly 5. A chalk line snapped over both gives a true cross to work from.
Dry-lay the quadrants. Without adhesive, lay tiles out from the centre cross toward each wall in turn. You are looking at where the cuts land. Two outcomes are acceptable: cuts of more than half a tile at every edge (balanced, generous) or a symmetric pattern of equal cuts on opposite walls (formal, deliberate). The failure case is a full tile on one wall meeting a 20 mm sliver on the other, that sliver is visible forever, and no grout colour fixes it.
Shift, don't settle. If the dry-lay reveals ugly cuts, shift the centre point by half a tile in the offending direction and re-check. A centred layout with slightly smaller field tiles on every side almost always beats an off-centre layout with one perfect side. If the room has a dominant feature, a fireplace, an open doorway into the main hall, the kitchen island, bias the layout so the most-seen view gets the cleanest pattern, and let the hidden corner absorb the cuts.
Choose the starting point for mechanical reasons too. The common professional choice is to start at the room's centre (working outward in all four directions, which keeps the field square even as walls drift) or at the most visible doorway (starting square to the entry sightline). Whatever you choose, the first tile goes down on the reference lines with its edges dead parallel to them, every subsequent tile inherits its position.
Mark, photograph, then clear the field. Snap chalk lines for the first rows, mark the position of the first dozen tiles, and photograph the dry-lay. Then pick the tiles back up. The adhesive clock starts on the next step, and you do not want layout decisions happening against it.
Stage Three: Adhesive: Choosing It and Spreading It
Buy by specification. Match the adhesive to the tile and location: standard grade for porous ceramic in dry interiors; flexible, polymer-modified (C2) grade for porcelain, large formats, floors with any movement, wet areas, and anywhere over a levelling compound. Flexible grade costs modestly more and is correct in every place standard grade is, so when the label is unclear, the flexible porcelain grade is the safe buy. For exterior floors, the adhesive must be rated for exterior use; interior wall adhesive on a balcony is a two-season failure.
Mix to the data sheet, and respect pot life. Powder into water per the stated ratio, mixed with a slow paddle to a lump-free, trowel-ridge-holding consistency, slaked 2–3 minutes, remixed. In hot weather, pot life shortens noticeably, mix smaller batches (enough for 15–20 minutes of laying) and discard, never retemper, adhesive that has begun to stiffen.
The notch controls the coverage. The trowel's notch size is matched to the tile, and the ribs it leaves collapse into a full bed when the tile is pressed and nudged:
Tile format
Notch size
Notes
|---|---|---|
Up to 200 × 200
6 mm
Small tiles, thin bed
250–400 mm
8–10 mm
The standard floor range
400–600 mm
10–12 mm
Back-butter the tile as well
Over 600 mm
12 mm +
Full back-buttering is mandatory
Spread, comb, and skin. Spread the adhesive with the flat face first (a thin contact skim on the floor), then comb through it with the notched edge held at a consistent 45–60°, one pass, one direction, even ribs. Work in a band you can tile within 10–15 minutes; combed adhesive left standing forms a skin, and skinned adhesive does not bond, it just fills the joint space. The test: after laying the first few tiles, pry one up. The ribs should have collapsed into near-total contact under the tile with no dry stripes. If they haven't, the bed is too thin, the pressing too light, or the adhesive too old on the wall of the notch.
Stage Four: Laying the Field
Press, slide, tap. Place the tile onto the combed bed, press it home with a firm palm, then slide it a centimetre across the ribs and back, this collapses the notches fully and seats the tile. Tap it level with a rubber mallet and check against its neighbours with a straightedge or the level across two or three tiles at once. You are managing two tolerances simultaneously: the surface (no lippage, the level shows it instantly) and the grid (the joints run true, the eye along the grout line shows it).
Spacers in every joint. Consistent spacers are what keep the grid true as tile-size variance accumulates. Check joint alignment every few rows by sighting down the lines and by laying the straightedge across the field, a joint drifting by a millimetre per row is invisible in isolation and unmistakable across ten rows. Remove protruding spacers that get adhesive on them rather than fighting them; a wet finger or spacer tool cleans excess adhesive from joints before it cures.
Leveling clips for large formats. Tiles 400 mm and larger earn their own tool: the leveling clip-and-wedge (or screw-cap) system. The strap sits in the joint, the wedge pulls adjacent tiles flush, and the clip is knocked off after the adhesive grabs, the result is lippage-free floors even where the tiles themselves vary a fraction of a millimetre in calibre. The system does not substitute for a flat screed, but on a good screed it delivers a surface that feels seamless underfoot.
Keep the field clean as you go. Adhesive squeezed into joints must be raked out before it cures, a joint filled with adhesive cannot accept grout, and scraping cured adhesive out of hundreds of metres of joint is the tiling world's least enjoyable task. A plastic scraper or the spacer tool run along each fresh joint takes seconds per tile; likewise wipe adhesive film off tile faces immediately with a damp sponge.
Work your way out, and off the floor. Plan the laying order so you finish near the door and never walk on fresh tiles. On a room of any size, work in sections with access boards, and keep the last row's cuts for the final session so you are not stepping over wet adhesive to reach them.
Stage Five: Cutting the Perimeter and Around Obstacles
Perimeter cuts are measured from the laid field, never from the plan's dimensions. Hold a full tile over the last laid tile, push it to the wall, and mark the gap, this measures the actual remaining space, absorbing every accumulated deviation. Remember the joint allowance at both the field side and the wall side of the cut. The full method, including notches, pipe holes, and corner cuts, is detailed in our common tiling mistakes guide, the principle here is only this: dry-fit every cut before it sees adhesive.
Straight cuts go through a score-and-snap cutter (fast, clean edges) or an angle grinder with a diamond blade for thicker porcelain. Curves and notches are nibbled with a tile nipper or ground with the grinder, the cut edge should end up against the wall, hidden, while the factory edge faces the visible joint. And leave the 6–10 mm perimeter gap at every wall: it is the floor's expansion allowance, and it disappears under the skirting.
Stage Six: Curing, Grouting, and the Wait That Pays
The adhesive needs its cure before the floor becomes a floor. The minimum is 24 hours with no traffic at all, no "just walking carefully to the kitchen", and 48 hours in cool or humid conditions. The floor is weakest now, and a tile shifted a millimetre by an early footstep carries that millimetre for its whole life.
Then the grouting sequence, which deserves its own full treatment in our grout selection and application guide: joints raked and vacuumed, grout mixed to the data sheet, packed with a diagonal float in manageable sections, the two-bucket clean, joints tooled as they stiffen, and the cure respected before wet use, 24 hours before foot traffic resumes on grouted floors, a full week before the shower is used in wet rooms.
Stage Seven: The Finishing Layer
The last five percent of the work delivers a hundred percent of the first impression:
Skirting cut and installed with the same joint discipline, its top edge sealed where it meets the plaster. Silicone sealant at the floor-wall junction in wet areas and at door thresholds where the floor meets a different material, movement joints get silicone, never grout. Final clean after full cure: haze removed with a dedicated remover or a dry microfibre, not acid on fresh grout. Sealer applied to grout joints after day seven in wet or stain-prone rooms, per the grout guide's cycle.
Then the punch-list walk before anyone is paid: tap-test for hollows, straightedge for lippage, coin-drag across joints, sight down every grout line once more in raking light. The sequence for that inspection is in the mistakes guide, and a floor that passes it was worth every waiting period this guide imposed.
Conclusion
Floor tiling is a sequence of small disciplines: a subfloor tested and levelled, a layout found by dry-laying rather than assumption, adhesive mixed fresh and combed to the right notch, tiles pressed and slid and checked in rows, spacers respected, clips used where formats demand them, cuts measured from the actual walls, and the cure periods treated as part of the work rather than an interruption of it.
None of the steps is difficult; the difficulty is keeping all of them. But the reward is the difference between a floor that is a permanent asset and one that is a permanent reminder, and if you are budgeting the job, follow on with our tile cost estimation guide to price each stage properly before the first bag of adhesive is opened.