ConstructionSantorini

F-16 · Finishes

Tiling

Tiling over waterproofing is the moment a terrace is made or ruined.

Short answer

The critical tiling decision on Santorini is what happens between the waterproofing and the tile. Bond a rigid finish straight onto a membrane on a terrace that swings twenty degrees daily, and movement in the tile tears the membrane. A separating layer and real movement joints are what prevent it.

What to expect

Typical durationBathroom 4–7 days · terrace 1–2 weeks
Cost bandFigures live in the cost index
Permit requiredNo
Seasonal constraintYear-round · external work avoids extreme heat

The terrace sequence, which is where money is lost

flashing over upstand ≥150 mm tile on adhesive separating layer liquid membrane primer screed to falls structural slab fall formed in the screed — minimum 1.5%, and it is checked with water, not a spirit level outlet at the low point, plus an overflow above it Terraces here take direct sun, then a 20°C swing overnight. Movement is the failure mode — not water pressure. Every penetration, upstand and corner is detailed before the membrane goes down, never after.
A-03 Terrace build-up over an occupied room. The order matters more than the brand: falls formed in the screed, not the tile bed, and a separating layer so movement in the finish never reaches the membrane.
  1. Falls formed in the screed beneath, verified with water. A tiler cannot fix a fall with adhesive thickness and should not be asked to.
  2. Waterproofing complete, with every upstand, corner and penetration detailed and tested before a single tile arrives.
  3. A separating layer over the membrane, so movement in the tile bed does not transfer into the waterproofing.
  4. Movement joints at perimeters, at changes of direction and at bay divisions, carried right through the build-up rather than stopping at the tile.
  5. Adhesive and grout specified for external exposure and thermal cycling, not for an interior floor.
  6. Perimeter joints filled with a movement sealant, not with grout.

Porous local stone and cement haze

Volcanic and other porous stone used here will absorb cement from grout and adhesive, and once absorbed it does not come out cleanly. What starts as a light haze becomes permanent clouding, and aggressive acid cleaning afterwards damages the stone surface.

The answer is prevention: sealing porous material before grouting, working in small areas, cleaning as you go rather than at the end, and using grout appropriate to the stone. It is slower, and it is the difference between a stone floor that looks right and one that has to be ground back.

Wet rooms

  • Waterproofing goes on before tiling, over the whole wet zone, not just the shower tray footprint.
  • Falls to the drain formed in the substrate. A wet room floor that relies on tile lipping to move water is a wet room floor that will pond.
  • In cave houses and old buildings, the whole-room strategy matters: sealing a wet room into a vapour-open building traps moisture in the wall behind it. The splash zones are tiled; the rest of the room stays breathable. See cave house damp proofing.
  • Extract ventilation sized for the volume and ducted out — the tiling is not the ventilation strategy.

Access, and the tile you cannot get there

Large-format tiles and slabs are heavy, rigid and awkward, and a substantial share of Santorini properties are reached by stepped pedestrian lanes.

A 120 cm slab that two people can carry across a level site is a genuinely different proposition on forty steps in Oia. It is not impossible — it is a cost and a risk, and both should be known before the tile is chosen rather than discovered on delivery day.

Questions people actually ask

My terrace tiles are cracking in a line. Why?

Almost always a missing or ineffective movement joint, or a rigid grouted perimeter. The crack is where the movement had to go. Repairing the crack without adding movement provision means it returns.

Can you tile directly onto the waterproofing?

Not on an external terrace. Without a separating layer, every bit of movement in the tile is transferred straight into the membrane you are relying on.

Can the cement haze on my stone floor be removed?

Sometimes, with the right treatment, and not always fully — and aggressive acid cleaning damages the stone. It is far cheaper to prevent it by sealing before grouting than to fix it afterwards.

Do you tile swimming pools?

Yes, with the specification that requires — the combination of chlorine, salt air, UV and constant immersion narrows the field considerably. See pool construction.

What size tile works in a vaulted room?

Generally smaller, or a cast finish instead. A large rigid grid fights a curved ceiling visually, and it is also harder to lay flat over a floor that follows the vault's original geometry.

One request. The right trade.

Tell us what needs doing

One request, two minutes. We read every one and point you at the tradesperson who handles this. Free, and you deal with them directly.

Message us

Ask about this page

A question about this specific job, or about something else entirely. It reaches a person, not a queue, and there is no obligation.

Your message will tell us you were reading Tiling

Plain words are better than trade words. If you have photographs, say so and reply to our email with them attached.

We use what you send only to answer you. Privacy.