The Stain Library

Material

Terracotta

A very porous unglazed clay tile that depends entirely on its sealer, which acidic and bleach based cleaners strip.

  • SurfacePorous
  • WashingSpot only
  • Colour run riskLow
  • Reviewed7 September 2026

What terracotta can and cannot take

  • Heat Use with care
  • Water and soaking Use with care
  • Acids, including vinegar Avoid
  • Strong alkalis Use with care
  • Solvents Use with care
  • Chlorine bleach Use with care
  • Abrasives Avoid

Always test on a hidden area first and let it dry before you treat the visible mark.

General rules for terracotta

The sealer is doing all the work, so protecting it is the whole method.

Warm water and a mild pH neutral detergent is the specification. Anything acidic, anything bleach based and anything aggressive takes the sealer off, and bare terracotta then absorbs everything it meets.

Dry the floor rather than leaving it wet. Terracotta holds moisture and a floor left wet dries with a bloom.

Check the label

Terracotta is a highly porous unglazed clay tile that has to be sealed to resist staining at all. UK retailers specify warm water and a mild pH neutral detergent, and warn that harsh chemicals and acidic or bleach based cleaners strip the sealer and leave the tile open to staining.

Stains on terracotta

Terracotta is low fired unglazed clay, and it is the most absorbent tile in common use.

The sealer is the surface

Unsealed terracotta absorbs water, oil and everything dissolved in them within seconds. Every practical instruction about terracotta is really an instruction about not damaging the sealer.

Acid and bleach strip it

UK retailers say so directly. That means the two products most people reach for in a kitchen or bathroom are the two that turn a protected floor into an unprotected one.

It blooms when wet

A terracotta floor left wet dries with a white haze as salts come to the surface, which is why drying the floor is part of the method rather than tidiness.

Resealing is routine

And is the answer to a floor that has started absorbing rather than shedding.

Sources

What we checked and when. Where a manufacturer instruction disagrees with anything here, follow the manufacturer.

  1. How to clean terracotta tiles, Walls and Floors retailer

    UK tile retailer guidance that terracotta is a highly porous unglazed clay tile that must be sealed to resist staining, that cleaning is done with warm water and a mild pH neutral detergent rather than anything acidic or bleach based, that harsh chemicals strip the sealer and leave the tile open to staining, and that the floor is dried rather than left wet.

    Checked 7 September 2026

  2. Quarry tile care and maintenance, Daltile manufacturer

    Tile manufacturer guidance that quarry tile is sealed before grouting and resealed regularly to protect against staining, that routine cleaning is multi purpose products or plain soap and water, that no rinse enzymatic and acid based cleaners are avoided because the combination of heat, food contamination and cleaner makes the grout soft and permanently damages it, and that a soft bristle brush suits the textured surface.

    Checked 7 September 2026

  3. Cleaning grout, Tile Council of North America trade body

    Tile trade body guidance that grout manufacturers do not advocate the use of acids because acids attack the cement in the grout, that grout is alkaline based and is dissolved by acids, that mildly alkaline cleaners are preferred over acidic ones, that oil and wax based cleaners leave a film that attracts dirt, that alkaline cleaner not properly rinsed leaves a sticky residue, and that cementitious grout should be sealed to prevent staining.

    Checked 7 September 2026