SELECTION CRITERIA FOR TILE It is necessary, first, to define what is meant by the slip resistance of a material, also termed its non-slip capacity, with relation to human perception. The following table, adapted from the table presented at Qualicer by Richard Bowman [Qualicer 2000], may serve to focus the concept and the need to consider this characteristic. EQUIVALENT SLIP RESISTANCE TERMINOLOGY Absolutely not slippery

Unquestionably safe

Safe for widest range of abnormal stride and pace

Slip highly improbable

Noticeably less slippery

Adequately safe

Safe for rapid stride and pace

Non-slip at very rapid pace

Acceptably safe

Safe for hurried stride and pace and minimal attention

Non-slip at rapid pace

Non-slip

Safe

Safe for normal stride and pace and moderate attention

Non-slip at involuntary pace

Detectably slippery

Marginally safe

Safe for normal stride, pace and attention

Non-slip with reasonable care

Noticeably slippery

Marginally unsafe

Safe for reduced stride and cautious pace

Non-slip with caution

Extremely slippery

Unquestionably unsafe

Safe for short stride and extreme care

Slip highly probable without extreme caution

Detectably less slippery

NOTE: Adapted from the ASTM D21.06 questionnaire reprinted in the journal Ergonomics, 1985, 28(7), 1062.

A second phase deals with flooring requirements as a function of traffic, location, presence of intervening materials (from a dry or wet condition to the presence of clay, dust, grease or oil), and flatness. Variables cannot be introduced regarding ways of walking or types of footwear. In regard to the flooring requirements described above, floors may be classified as follows: ► ►

► ► ►

Internal in private residential architecture Internal in private residential architecture, but communicated with the outside. External and stair treads Heavily trafficked internal flooring (publicly trafficked architecture) Heavily trafficked internal flooring communicated with the outside.

Physico-chemical characteristics · Slip resistance Selection criteria for tile

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► ► ►

Outside floors and stairs. Water-related domains. Areas of industrial activity or with special risk.

taking as fundamental parameters: traffic intensity, presence or absence of water (and dust or dirt), and building areas with special risk. The foregoing classification does not include flatness, since the presence of slopes is obviously an important risk factor. Thirdly, it is necessary to take into consideration the information supplied by manufacturers and the available normative references. The Designer or Specifications Writer will also need to take into consideration national regulations. Manufacturers customarily continue to reference their products with the dry and wet dynamic coefficient of friction obtained with the floor friction tester (FFT) [COF class 1 or COF class 2]. Some manufacturers, with clients in the European markets, provide the results of the ramp test and even the drainage volume codes [V4–V10]. We do not know what information manufacturers provide for the American market and whether they continue to use the ASTM C1028 test method. In the international context, the following more or less consolidated trends may be noted: ► ►

►

Use of the dynamic floor friction tester (FFT) only for the dry test. Use of the British pendulum test for the wet test, slip risk evaluations being assigned as a function of national standards and regulations, with the option of TRRL soft rubber sliders for profiled tiles. Use of the ramp method in its different modes for tiles intended for flooring with special risk.

Tables 1 and 2 present the classes according to the British wet pendulum test and the linkage of those classes to the intended tile service application.

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WET SLIP RESISTANCE LEVELS OF MODULAR RIGID MATERIALS ACCORDING TO THE BRITISH PENDULUM TEST Class

[*]

Pendulum scale

Slip risk

(Four S rubber slider)

(TRRL soft rubber)

V

>55

>45 [*]

Very low

W

45–54

40–44

Low

X

35–44

-

Moderate

Y

25–34

-

High

Z

75), satisfactory (40-74), marginal (20-39), and dangerous (≤19)

SOURCE: Assessing the relative contribution of ceramic tiles to slip and fall accidents. RICHARD BOWMAN. Proceedings Qualicer, 1998. PGII, pages 161-172

Table 1 Classification of materials intended for flooring in terms of the results of the British wet pendulum test.

GUIDANCE ON INTENDED TILE USE AS A FUNCTION OF THE SLIP RESISTANCE CLASS DEDUCED FROM THE BRITISH WET PENDULUM TEST

[*]

Intended tile use

Tile class

External flooring Wet internal flooring Heavy traffic areas Dry sloping floors Flat dry floors

V, W V, W V, W, X V, W, X, Y V, W, X, Y, Z [*]

Consider a dry coefficient of friction of at least 0.4 according to the floor friction tester (FFT)

Table 2

Table 3 presents the ranges of slip resistance requirements taken from document BGR 181.

Physico-chemical characteristics · Slip resistance Selection criteria for tile

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CLASSIFICATION OF BUILDING AREAS WITH RESPECT TO SLIP RISK [*] Requirement level according to DIN 51130[1]

Building area 0.- Work areas y External accesses y Internal accesses y Accesses connected with the outside y Internal stairs y Internal stairs connected with the outside y External stairs y Sanitary areas (toilets, changing rooms,...) y Rest areas 1.- Food industry (oil, grease, margarine) 2.- Food industry (processing and transformation of dairy products) 3.- Food industry (processing of chocolates and sweets) 4.- Food industry (processing of bakery products) 5.- Meat industries 6.- Food industry. Fish and their transformation. Manufacture of delicatessen. 7.- Food industry. Processing and transformation of vegetables. 8.- Wet areas in the processing of food products and drinks (wine cellars and packaging plants) 9.- Kitchens and dining rooms [*]

[1] [2]

R10-R11 R9 R10 R9 R10 R10-R11 R10 R9 R12-R13 R11-R12 R11-R12 R11-R12 R12-R13 R13

Drainage capacity

V4

V4 V4-V6 V4 [2] V6-V10 V4-V10

R11-R13 R10-R11

V4-V6

R10-R12

V4

Document BGR 181 (October 2003) [former ZH 1/571, of 10/1993]: FLOORS IN WORK ROOMS AND WORK AREAS WITH SLIP RISK. Range of minimum requirements as a function of type of building area and activity (detailed in the BGR 181 document) Only in building areas for washing

Table 3

Based on these premises and with a view to establishing safety margins in the slip resistance of modular rigid floorings in general and of ceramic floorings in particular, the following selection criteria may be used for tile: ► In the internal flooring of the dwelling, one should consider the non-slip capacity of the tile in areas with risk: galleries, bathrooms, and rooms directly connected with the outside. Slip resistance may be assured using tiles that display the following features: • Dry coefficient of friction, according to the floor friction tester (FFT), of 0.4 or larger. • Class Y, according to the British wet pendulum test. • Class 1, according to document SUA 1 (Spanish CTE) and the test method laid down in European experimental standard ENV 12633. ► In flooring and stairs outside dwellings, internal flooring and stairs subject to heavy traffic in publicly trafficked architecture connected with the outside, it is recommended to select slip resistant tiles that provide a low level of risk: • Class X, W, or V according to the British wet pendulum test. • Class 2 according to document SUA 1 (Spanish CTE) and the ENV 12633 test, foreseeing wet conditions in cleaning operations and the presence of dust or dirt owing to lack of cleaning. Physico-chemical characteristics · Slip resistance Selection criteria for tile

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This risk group includes internal flooring with a slope of less than 6%. ► In internal flooring and stairs of publicly trafficked architecture connected with the outside it is necessary to select tiles of classes V or W according to the British wet pendulum test, or to consider R10 or R10 V4 according to the ramp test (DIN 51130). This selection also includes floors with a slope of less than 6% or building areas that may be sporadically wet. ► For outside public floors and stairs, as well as interiors that are frequently wet (showers, saunas, and communal changing rooms), the slip resistance requirement that assures a low or very low level of risk is provided by: • Classes V and W according to the British wet pendulum test • R10 V4 according to the oil-wet ramp test (DIN 51130) • Classes 2 or 3 according to SUA 1 (Spanish CTE) With slopes of 6% or higher, class 3 is required, also in outside flooring in SUA 1 (Spanish CTE) ► The special slip resistance requirement, always associated with a very high level of risk, is applied to: • Water-related domains in general (swimming pools and their surroundings, leisure facilities, bathing resorts, etc.) where tiles of classes A, B, or C should be selected, resulting from the ramp test for barefoot use of wet flooring (DIN 51097) and based on the recommendations of the German GUV-I 8527 (former GUV 26.17) regulation. In addition, in the case of Spain, class 3 according to SUA 1 of the CTE. • Commercial areas and areas of industrial activity that both exhibit the presence of substances that favour slipping, independently of whether these areas are dry or wet, or the existence of slopes, in which tiles shall be referenced by the ramp test according to DIN 51130 and, in some cases, also referenced in relation to their drainage capacity. Tiles shall be classified in regard to slip resistance between R10 and R13 (DIN 51130 test) and between V4 and V10 (profiled tiles, with volumes of water or dirt evacuation between 4 and 10 cm3/dm2), the guidelines being recommended of the German Regulation BGR 181. The following chart provides a synopsis of the selection criteria for tiles based on their intended use and required slip resistance.

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TILE SELECTION AS A FUNCTION OF THE FLOOR SLIP RESISTANCE REQUIREMENT Intended service application ►

Dwelling interiors (flooring with risk)

►

Floors and stairs outside dwellings Internal floors and stairs with heavy traffic Internal floors with a slope less than 6%.

► ►

Recommended class

Reference to standard or regulation

Dry COF ≥ 0.4 Class Y Class 1

FFT Wet pendulum SUA 1 (CTE, Spain)

Class X, W, or V Class 2

Wet pendulum SUA 1 (CTE, Spain)

►

Internal floors directly connected with the outside in publicly trafficked architecture, with slope, or sporadically wet.

Classes V or W R10 or R10 V4

Wet pendulum DIN 51130

►

Publicly accessed outside floors and stairs, in addition to frequently wet interiors, and slopes of 6% or higher

Classes V or W R10 V4 Class 2 or 3

Wet pendulum DIN 51130 SUA 1 (CTE) 6/33

►

Floors with special requirements: • Water-related domains for barefoot use

Classes A, B or C

DIN 51097 GUV-I 8527

R10 – R13 V4 – V10

DIN 51130 BGR 181

• Commercial areas and industrial areas with special risk

In accordance with the foregoing chart, non-slip tiles are usually those that display low or very low slip risk. Roughly speaking, this places us in the third row of the foregoing table, with classes V or W according to the British wet pendulum test and classes R10 or R10 V4, according to the oil-wet ramp test of standard DIN 51130. Tiles with special slip resistance are those tested according to the wet ramp method, both with standard footwear and by the barefoot test, in addition to taking into account the recommendations of regulations GUV-I 8527 and BGR 181.

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