Porcelain tiles: what they are and how to choose

What porcelain tiles are

Porcelain tiles, often searched in Tanzania as posline tiles, are ceramic tiles with a dense body fired until it absorbs almost no water. The European tile standard sorts tiles by that figure. The Villeroy & Boch wear-resistance sheet lists porcelain stoneware under DIN EN 14411, group BIa: it may absorb no more than 0.5% water.

Vitrified tiles is the trade name Indian catalogues use for tiles of the same kind. The label “porcelain” or “vitrified” on a box proves little by itself; the water absorption value, if printed, is what places a tile in BIa.

Glazed, polished and full-body porcelain

Modern porcelain tile comes in three main builds. The difference is where the pattern sits and what is left when the surface wears.

Glazed, polished and full-body porcelain

Type	What you see	What wears
Glazed porcelain (GVT in Asian catalogues)	Printed glaze over a porcelain body	The glaze layer, depending on how hard and thick it is
Polished glazed (PGVT)	Glaze polished to a gloss	The glaze; a polished gloss is one of the finishes the sheet names as a wear factor
Full-body or unglazed porcelain	The same colour through the whole thickness	The body itself; deep abrasion is limited to 175 mm³ under DIN EN ISO 10545-6

For porcelain tile flooring at home, a glazed tile in the right wear group is enough. Villeroy & Boch says unglazed porcelain shows almost no wear even after decades of intensive use, and recommends it for the hardest-used spots such as shop entrances.

Non-slip porcelain tiles

Non slip tiles are graded by a ramp test, not by how rough they feel. The acceptance angles for shod feet, as printed in the Villeroy & Boch slip-resistance sheet:

Non-slip porcelain tiles

Class	Angle reached on the ramp
R9	6°–10°
R10	over 10°, to 19°
R11	over 19°, to 27°
R12	over 27°, to 35°
R13	over 35°

Barefoot areas have their own classes: A from 12° to 18°, B above 18° up to 24°, C above 24°. Showers and pool surrounds need at least B under the German rules the sheet quotes. Examples from the same workplace rules (ASR A1.5):

• toilets: R9;
• changing rooms and washrooms: R10;
• outdoor entrances: R11, or R10 with a 4 cm³/dm² displacement space (V4);
• restaurant kitchens: R12.

An anti slip tile or non slip ceramic tile marked R10 therefore meets the class those rules set for washrooms; for a walk-in shower, look for a barefoot class as well. These are workplace rules: the sheet notes that none exist for private bathrooms. The sheet adds that small tiles grip better than large ones of the same surface, because the joints help.

Large format: 1200 × 600 and 600 × 1200 tiles

1200x600 tiles and 60x120 tiles are the same size, named in a different order. Each piece is 0.72 m² (our calculation: 1.2 m × 0.6 m), so a 15 m² room takes 21 tiles before cuts (15 ÷ 0.72 = 20.8). Fewer pieces mean fewer joints, which also means less of the grip that joints give.

The large format tile Kitovu keeps in Zanzibar is the Beige Porcelain Tile 1200 × 600 mm, Matt Anti-Slip R10: a beige floor tile with a stone look and a granular matt surface. Thickness, box contents and water absorption are not confirmed for this item yet; ask on WhatsApp before you plan a large order.

Where porcelain floor tiles go

Floor wear groups for glazed tiles run from 1 to 5; group 0 is not for floors. The same wear sheet puts a whole living area, bathrooms and balconies in group 3, kitchens, private entrances and terraces in group 4, and restaurants and hotel lobbies in group 5. Porcelain floor tiles for the kitchen and terrace side of a house therefore need group 4.

For a full comparison with ceramic tiles and a size table, see floor tiles. Wet-room choices are on the bathroom tiles page.