What you’ll need
Step by step
Check the surface and clean it down
The substrate must be structurally sound and free from dust, grease, oil, paint and curing compounds. A cement screed must be fully cured and dry before tiling. Tap the floor and mark any hollow or cracked areas; repair them first. Sweep and vacuum all dust. For highly absorbent substrates, dampen with clean water and drain off the excess so the surface is damp, not wet — this stops the screed drinking the water out of your adhesive. For tile-on-tile, sound every old tile, re-fix or remove any that drum, degrease, and key the glossy glaze.
Level an uneven base with Floorscreed
Large and regular-size tiles need a flat base. Check the floor with a long straightedge; where it dips or humps beyond tolerance, level it first with SUMO Floorscreed and let it cure and dry before tiling. A flat base is what stops lippage and hollow spots later.
Set out the floor
Find the centre of the room, dry-lay a row of tiles to check the layout, and snap chalk lines so cut tiles fall at the least visible edges. Decide your starting point so you tile out of a corner, never into one. Plan a consistent joint width and mark it.
Mix the adhesive
Pour about two-thirds of the clean water into the bucket, then add the S02 powder slowly while mixing with a low-speed drill and paddle. Add the remaining third of water and mix to a smooth, lump-free, creamy paste. Let it rest (slake) for 2–3 minutes, then re-stir briefly. Mix only as much as you can lay within the working time.
Spread and comb the bed
Hold the trowel's flat edge and press a thin, firm skim of adhesive onto the floor to key it in. Then comb it out with the notched edge at about 45°, in straight lines in one direction, to an even ribbed bed (up to ~6 mm). Comb only the area you can tile in about 10 minutes — before the ridges skin over.
Lay and bed each tile
Place the tile onto the ridges just off its final position and press it down with a firm slide across the ridges to collapse them and drive out air, then nudge it home. Tap gently with a rubber mallet to bed it level. Drop in spacers and keep to the chalk lines.
Check the coverage on the first tiles
Right after bedding the first tile, lift it back up and look at the back. The flattened adhesive should cover at least 80% of the tile back for a dry interior floor, with no bare corners. If you see clean stripes, comb a deeper bed (or back-butter the tile) and re-check.
Level, align and space
As you lay, run a straightedge or level across the tiles and adjust any high or low tile with the mallet while the bed is still fresh. Keep joints straight and consistent with spacers (or levelling clips for larger tiles). Check lippage between adjacent tiles by hand.
Clean off as you go
Wipe adhesive off the tile faces and rake it out of the joints before it sets — leave the joints about two-thirds deep and clear, ready for grout. Wash tools and buckets in water immediately; cured adhesive only comes off mechanically.
Let it cure, then grout
Keep foot traffic off the floor while it sets. Allow the adhesive to cure — typically around 24 hours (longer in cold or damp conditions) — before grouting. Then fill the joints with SUMO Sumoxy 2-Part epoxy grout (or Sumoxy 3-Part for larger joints) — waterproof, stain-free and hard-wearing — clean within the window, and let the finished floor cure.
What to take care of
Pro tips
What to avoid
Dabbing adhesive at the corners and centre leaves voids under the tile. Always comb a full, even bed.
Too small (or a rounded, worn trowel) gives a shallow bed and poor coverage. Match the notch to the tile and replace worn trowels.
S02 past its pot life is dead — you can't revive it with water. Mix in batches you can lay in time.
No flat, clean key means poor coverage and lippage. Level with Floorscreed, clean, dampen porous surfaces, and key any glossy tile-on-tile.
You only find out the bed was too thin when the floor sounds hollow. Lift a tile early.
Exterior, wet areas, large formats, stone — those need S02+, S03 or S04.