A glazed outdoor tile has a thin layer of fired glaze on top, which carries the printed design. An unglazed tile has no such layer: its surface is the body itself, and its colour runs through the tile. Glazed tiles offer more looks; unglazed tiles hide wear better.
Both can be dense porcelain with very low water absorption. The difference is at the surface, and that surface is what people walk on, clean and complain about.
How each is made
For a glazed tile, the pressed body is coated with an engobe and glaze, printed digitally and fired. Most GVT and many outdoor ranges in Morbi are made this way. The print can reproduce stone, wood or concrete in fine detail. Our guide on GVT tiles explains the process.
An unglazed tile is coloured in the body powder. Full-body porcelain carries one colour or mix through the whole thickness. Double-charge tiles have a thick coloured top layer pressed onto a base. Some unglazed tiles get a surface texture from the mould, but no glaze.
The practical differences
- Looks: glazed tiles can show almost any design; unglazed tiles are limited to what pigments mixed in the body can produce.
- Wear: on a glazed tile, heavy wear can dull the glaze or expose the body below; on an unglazed tile, wear exposes the same colour.
- Chips: a chip in a glazed tile can show a different colour underneath; a chip in a full-body tile is much less visible.
- Grip: unglazed textured surfaces give natural grip; glazed outdoor tiles usually need a structured face or grit in the glaze.
- Cleaning: glazed surfaces are usually easier to wipe clean; some unglazed surfaces can hold dirt in their texture.
Different tests for wear
EN 14411 treats glazed and unglazed tiles differently for abrasion. Glazed tiles are tested to ISO 10545-7 and given a PEI class, which shows how the glaze stands up to wear. Unglazed tiles are tested to ISO 10545-6 for deep abrasion, which measures how much material is worn away.
So ask for the right report. A PEI class on an unglazed tile, or a deep abrasion figure on a glazed one, suggests the seller does not know the product. Our guide on PEI ratings explains the glazed scale.
Which to choose outdoors
- Choose unglazed or full-body for public paths, commercial entrances, parking areas and other heavy traffic.
- Choose glazed for private terraces, gardens and balconies where looks matter most and traffic is light.
- For both, insist on porcelain with water absorption of 0.5% or less if the site freezes.
- For both, ask for a slip report on the exact surface you will buy.
Colour stability is not a reason to choose one over the other. Both types use fired ceramic pigments that do not fade in sunlight, as explained in whether outdoor tiles fade.
Next step
We check whether a tile is truly glazed, full-body or double-charge, and that its reports match its type. To plan an outdoor range, book a free sourcing review.