Prep checklist
Skip any step here and you will fight lippage or hollow spots later. Flatness and the right mortar matter more than expensive tile.
- Install backer board or membrane; flatness within 1/8 inch per 10 ft for large tile
- Snap chalk lines from room center — balance cut tiles at walls
- Dry-lay a row without mortar to preview cuts
- Have correct thinset (modified vs unmodified) for substrate and tile type
- Mix thinset to peanut butter consistency — slake 10 minutes, remix
Layout strategy
Centered grid looks formal; start from main entry for fewer small cuts in the sightline. Hide narrow cut tiles under cabinets if kitchen tile stops at toe kick.
Dry-lay the first two rows fully before mixing mortar. If end cuts are under 2 inches, shift the starting line so both walls get balanced pieces.
Thinset and trowel quick reference
Comb thinset in one direction, then set the tile with a slight slide perpendicular to the ridges. Pull a tile occasionally to confirm coverage — aim for 80%+ indoors, 95%+ wet areas.
- Modified thinset: plywood, backer board, most porcelain
- Unmodified: some membranes and absorbent substrates — read tile spec
- 1/4 × 1/4 notch: many 12×12 and smaller floor tile
- 1/2 × 1/2 notch: large format 12×24 and bigger
- Back-butter large tile — full coverage on back, no voids
Tools and box counts before mortar day
Have spacers, leveling clips (for large format), a wet saw, and enough tile on site before you mix. Running short mid-layout forces a dye-lot scramble. Confirm cartons with the tile calculator at 15% waste minimum.
Read large format tile tips if any side is 15 inches or longer — prep tolerances tighten fast.