homeX
2026-11-06T09:15:58

Ceramic Tile Water Absorption Groups BIa, BIb, BIIa, BIIb (ISO 13006)

瓷砖吸水率组别BIa、BIb、BIIa、BIIb（ISO 13006）

Ceramic tile water absorption under ISO 13006:2018 (and the SNI ISO 13006 edition required in Indonesia) splits dry-pressed tiles into BIa (E ≤ 0.5%), BIb (0.5% < E ≤ 3%), BIIa (3% < E ≤ 6%) and BIIb (6% < E ≤ 10%). E is the mass percentage of water absorbed by the tile body, tested by the vacuum method in ISO 10545-3 (the 2018 edition no longer uses the boiling method). This article focuses only on the absorption groups: what the percentages mean, indoor versus outdoor choices, and how they differ from PEI.

Key Facts

How to read ceramic tile water absorption codes BIa–BIIb

ISO 13006 classifies tiles on two axes: manufacturing method and water absorption. The first letter:

  • A = extruded tiles
  • B = dry-pressed tiles — the type most common in Indonesian building stores
  • C = other methods

Roman numerals mark the absorption group: I low, IIa/IIb medium, III high. For dry-pressed tiles, Annexes G–L of ISO 13006:2018 set:

  • BIa — Ev ≤ 0.5%
  • BIb — 0.5% < Ev ≤ 3%
  • BIIa — 3% < Ev ≤ 6%
  • BIIb — 6% < Ev ≤ 10%
  • BIII — Ev > 10% (typically wall tiles)

Ev is measured as a mass percentage. The lower the figure, the denser the body, usually with higher flexural strength and better stain and frost resistance.

Indoor or outdoor: picking the right group

  • BIa (≤0.5%): porcelain / granite tile. Dense and strong; first choice for terraces, carports, open balconies and busy floors. Also fine for wet indoor areas if the surface is anti-slip enough.
  • BIb (0.5–3%): dense stoneware. Suits interior floors and semi-outdoor spots that are not constantly soaked by heavy rain.
  • BIIa (3–6%) and BIIb (6–10%): common interior floor tiles — living rooms, bedrooms, dry corridors. Avoid as open-terrace floors that stay wet.
  • BIII (>10%): wall tiles. Light and easy to fix, but not for floors.

The standard gives technical characteristics, not a mandatory room list. Final choice still follows the drawings, local weather and the maker's box notes.

Water absorption versus PEI

Buyers often mix the two labels on the box. In short:

  • Water absorption (groups BIa–BIII) = how the tile body takes up water; critical outdoors, in wet zones and where freeze–thaw or expansion cracking is a risk.
  • PEI (I–V) = glazed-surface abrasion resistance per ISO 10545-7; critical for foot traffic. PEI does not apply to unglazed full-body porcelain, which is tested by deep abrasion.

A BIa tile with a low PEI can still wear fast in a mall; a BIIb tile with PEI IV can still fail on a rainy terrace. Read both, plus the SNI ISO 13006 mark and the shade/calibre codes.

Quick checklist in the store

  • Look for the group (BIa/BIb/BIIa/BIIb) or the absorption percentage on the box or technical sheet.
  • For outdoors and carports, prefer BIa or at least BIb.
  • Bathroom walls may use BIII, but bathroom floors are safer in BIa/BIb with an anti-slip surface.
  • Adhesive: very low-absorption BIa granite tiles usually need a C2 adhesive, not a plain cement slurry.

homeX, an Indonesian one-stop building materials and furniture platform with showroom, warehousing and delivery, helps compare absorption-group specs across brands before you order.

ceramic tile water absorption: related articles and products

FAQ

What does BIa mean on a tile box? BIa is a dry-pressed tile with water absorption Ev ≤ 0.5% under Annex G of ISO 13006:2018; usually porcelain / granite tile.

Can BIIb be used on a terrace? BIIb absorbs 6–10% water and suits general interior floors. For open terraces, prefer BIa or BIb.

How does water absorption differ from PEI? Absorption rates the tile body against water; PEI rates glaze wear. Check both separately.

For building and renovation material needs, reach the homeX team on WhatsApp +62 821 1818 998, by email at homex9998@gmail.com or through our contact page.

Sources: ISO 13006:2018 preview, Ceramic tiles — definitions, classification, characteristics and marking; homeX, How to choose floor tiles: PEI, water absorption and SNI ISO 13006; Eagle Assurance House, Ceramic tile classification by ISO and EN standards