How to read tile specifications: PEI, slip resistance, breaking strength and chemicals

Key points

PEI (per ISO 10545-7) rates the abrasion resistance of glazed tile surfaces from 0 to 5; it doesn't apply to unglazed tile.
Slip resistance is expressed by different methods that can't be converted: R9–R13 (ramp with shoes and oil), A/B/C (barefoot), and DCOF (US).
ANSI A326.3 requires wet DCOF ≥ 0.42 for level interior floors expected to be walked on when wet.
No tile is absolutely 'non-slip'; the figures help selection but don't guarantee safety alone.

Written for:OwnerContractorSupplier

The technical data sheet is the tile's "ID card". Reading it correctly avoids costly mistakes like a slippery polished tile in a bathroom, or a weak glazed tile in a busy entrance. This guide explains the key figures and their sources.

1) Surface abrasion resistance — the PEI rating

ISO 10545-7 defines how to measure the abrasion resistance of glazed tile surfaces1. In the test the tile is subjected to rotating steel balls, aluminium oxide grit and water, and the number of revolutions at which visible wear appears is recorded1:

Class	Revolutions until wear appears	Recommended use (per manufacturer's technical guide)
0	100	Not recommended for floors.
1	150	Floors walked on with soft shoes or barefoot without abrasive dirt (bathrooms and bedrooms without a direct outdoor entrance).
2	600	Living rooms except kitchens, entrances and busy areas.
3	750 / 1,500	Areas walked on often with normal shoes: open kitchens, halls, corridors, balconies.
4	2,100 / 6,000 / 12,000	Higher regular traffic: commercial kitchens, hotels, showrooms and sales areas.
5	Over 12,000 (plus passing the stain test ISO 10545-14)	Heavy traffic for long periods: shopping centres, airport halls, hotel lobbies.

Important: PEI doesn't measure the tile's overall "quality", only how suitable its glazed surface is for a location1. Unglazed through-body tile is measured by a different test, "deep abrasion" ISO 10545-6, and technical guides state it is practically suitable for most areas including heavy traffic1.

Put a doormat or scraper at external entrances; they remove dirt and abrasives and protect glazed floors, especially in rooms entered directly from outside1.

2) Slip resistance: three different languages

You'll find slip resistance written in one of the following ways. Values cannot be converted from one method to another, because each test uses a different contaminant and footwear2.

a) R rating (German DIN 51130 test)

A person in standard cleated boots walks on an oil-covered ramp whose angle is raised gradually until the limit of safe walking2. The average angle achieved sets the class, and R13 is the highest3:

Class	Angle	Common uses
R9	6° – 10°	Dry interior areas.
R10	over 10° – 19°	Domestic kitchens, toilets, areas with light wetting.
R11	over 19° – 27°	Wet and exterior areas, gentle ramps.
R12	over 27° – 35°	Commercial kitchens, wet industrial areas.
R13	over 35°	Industrial areas heavily contaminated with oils and grease.

b) A/B/C barefoot rating (DIN 51097)

Used for floors walked on barefoot, such as pool surrounds and shower floors; the contaminant is soapy water2. Requirements increase from A to C: A over 12° to 18°, B over 18° to 24°, C over 24°4.

In 2021 EN 16165 superseded DIN 51130 and DIN 51097 and contains no R or ABC categories, but the German DIN EN 16165 keeps them; so reference DIN EN 16165 when an R or ABC rating is required2.

c) Dynamic coefficient of friction DCOF (US standard)

The US standard (ANSI A137.1, referring to test method ANSI A326.3) requires wet DCOF of 0.42 or more for tiles recommended for level interior floors expected to be walked on when wet5.

No floor is completely "non-slip". Technical guides state that a laboratory DCOF value is not a definitive indicator of whether slips will occur, as real conditions depend on contaminants, footwear, maintenance and conditions of use5. For on-site testing of an installed floor, UK experts recommend the pendulum test rather than the ramp test2.

3) Breaking strength

Measured per ISO 10545-4 by three-point loading, and given in newtons. One European technical guide suggests this indicative load grouping1:

Breaking strength	Stress group	Examples
Under 1,500 N	1	Residential and similar buildings.
1,500 – 3,000 N	2	Offices and shops, pneumatic-tyred trolleys.
3,000 – 5,000 N	3	Shopping centres with rubber-wheeled forklifts.
5,000 – 8,000 N	4	As above with polyamide wheels.
Over 8,000 N	5	Factories, warehouses and heavy vehicle workshops.

The actual strength of a floor depends largely on installation quality and adhesive coverage under the tile, not on the tile alone1. See professional tile installation.

4) Chemical and stain resistance

Household chemicals and pool salts (ISO 10545-13): classes A/B/C, with A the most resistant1.
Acids and alkalis: at low (LA/LB/LC) or high (HA/HB/HC) concentration, with A the best1.
Stain resistance (ISO 10545-14): classes 1 to 5, with 5 the highest (easiest to clean)1.

5) Other properties on the sheet

Frost resistance (ISO 10545-12): less important in most of Saudi Arabia, but an indicator of tile density.
Crazing resistance (ISO 10545-11): tiles with deliberate crazing in the design need wetting before grouting, and don't suit coloured grout1.
Dimensional tolerance: rectified tiles are more accurate and allow narrower joints.

Quick selection table

Location	Absorption	PEI (glazed)	Slip (by the method stated on the data sheet)
Bedroom	Any floor group	2 or higher	R9 usually enough
Living room / corridor / home kitchen	BIa or BIb	3 or higher	R9–R10
Bathroom floor	BIa or BIb	2–3 or higher	R rating: R10 or higher DCOF test: wet ≥ 0.42
Shower floor	BIa	—	R rating: R11 Barefoot test (DIN 51097): B or C
Entrance / courtyard / external stairs	BIa	4 or higher, or unglazed	R11 or higher

The slip column gives a limit for each test method separately; two values in one cell come from different tests, are not equivalent and cannot be converted, so apply the limit for the method stated on your product's data sheet. This table is indicative, based on the explanations above; the final decision rests with the manufacturer's recommendation, project requirements and the adopted code.

Sources

The number next to a statement points to its source in this list. Sources back the general information; anything marked “practical advice” is editorial experience, not a quoted source. Anything that affects safety, structural design or electrical installations needs a licensed professional, and in Saudi Arabia the binding reference is the Saudi Building Code.

1Application Technique — Terms and Classifications according to DIN EN 14411 — AGROB BUCHTAL / Deutsche Steinzeug
2What is DIN 51130 / DIN 51097 ramp testing? — UK Slip Resistance Group (UKSRG)
3DGUV Regel 108-003: Floors in workrooms and work areas with slip hazard (Table 1: R9–R13 groups by inclination angle) — German Social Accident Insurance (DGUV) — BG BAU edition, 2003-10
4DGUV Information 207-006: Floor coverings for wet barefoot areas — 3 Requirements (A, B, C groups) — German Social Accident Insurance (DGUV) — BG BAU edition
5DCOF AcuTest®: Testing Slip Resistance — Reading Test Results — Daltile

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This guide is for general information and planning, based on standards and technical guides. Standards are revised periodically; in Saudi Arabia the binding reference is the Saudi Building Code and the instructions of the competent authorities. For design and execution, use a licensed engineer or technician. Found an error? Tell us.