Specifying tiles for commercial environments means making decisions that will affect the performance, safety, and appearance of a space for decades. Whether you are an architect, interior designer, contractor, or facilities manager, specifying the right commercial tile requires more than an eye for aesthetics.

This guide sets out the technical framework behind Parkside's commercial tile range. It covers the standards, metrics and specification criteria that matter most when tile selection moves beyond the sample room and into a live project.

Please note: This guide has been produced to explain more about the technical terminology used within tile industry that you may encounter on a general level. However, it is not intended as a substitute for a specification consultation with one of our tile technicians, which you can arrange here, or by visiting one of our design studios in person.

Core Performance Metrics

Choosing the right tile for a commercial environment means going beyond aesthetics. Rather than going on how a tile may look on a sample board, core performance metrics analyse how the tile will actually behave once in service.

Every commercial tile specification should be built on measurable performance data. The following core metrics cover aspects governed by BS EN ISO standards.

They exist to ensure that the tile chosen for a project can actually handle the demands of the environment it will be installed in.

Abrasion Resistance

Abrasion resistance measures how well a tile surface withstands wear from foot traffic and friction over time, tested differently depending on whether the tile is glazed or unglazed.

Glazed tiles are rated on the PEI scale from 0 to 5 based on how much visible surface wear occurs under a standardised rotating abrasive test.

Unglazed tiles are measured by the volume of material removed in mm³ under the same abrasive conditions

A glazed tile wears through its surface coating while an unglazed tile wears through its body.

  • PEI Rating (Porcelain Enamel Institute)
    • PEI 0 = wall tiles only
    • PEI I = very light traffic
    • PEI II = light residential
    • PEI III = moderate traffic
    • PEI IV = heavy commercial
    • PEI V = very heavy / industrial

In commercial practice it is the metric that most directly determines whether a tile will still look acceptable after five or ten years of use rather than just on installation day.

A PEI III tile specified in a heavy retail or transport environment will show visible glaze wear within months, and because worn glaze cannot be restored the only remedy is retiling.

This makes abrasion resistance one of the most commercially consequential specification decisions, particularly on large floor installations where replacement cost and business disruption are significant.

Standard: BS EN ISO 10545-6 (glazed), BS EN ISO 10545-7 (unglazed)

Adhesive and Grout Classification

Adhesive classification describes the performance characteristics of the fixing material rather than the tile itself, with cementitious adhesives rated under a letter and number system.

  • Adhesive: C1, C2 (cementitious), D1, D2 (dispersion), R (reduced slip), T (non-slump), E (extended open time), F (fast set)
  • Grout: CG1, CG2, RG, EG (epoxy)

In commercial practice the classification matters because specifying a C1 standard adhesive behind an R11 rated porcelain tile in a commercial kitchen wet area is a system failure waiting to happen regardless of how good the tile itself is.

Instead, the adhesive and grout must be matched to the demands of the environment, the tile format and weight, the substrate type and the thermal and moisture conditions of the space. For this reason, BS 5385 requires the complete system to be specified rather than the tile alone.

Standard: BS EN 12004 (adhesives), BS EN 13888 (grouts)

Breaking Strength and Modulus of Rupture

Breaking strength assesses the structural integrity of a tile under load. It gives the absolute force in Newtons required to snap a tile in half across a supported span

Modulus of rupture measures the tile's resistance to bending stress normalised against its thickness and width to give a comparable figure across different tile sizes.

In combination, they describe how structurally robust a tile body is under load,

  • Breaking strength: minimum 1,300N for tiles with surface area >90cm²
  • Modulus of rupture: minimum 35 N/mm² for porcelain

In commercial practice both figures matter most when specifying large format tiles or thin porcelain panels. Additionally, any application where tiles will be subject to point loading, impact, or spanning voids such as raised access floors and drain channels.

A tile can pass every other performance metric and still fail in service if its body is insufficiently strong to handle the mechanical demands of the installation. In particular, thinner large format tiles in particular can have deceptively low breaking strength figures despite high modulus of rupture ratings due to reduced cross-sectional thickness.

Standard: BS EN ISO 10545-4

Chemical Resistance

Chemical resistance measures how well a tile's surface withstands exposure to household chemicals, pool chemicals, acids, and alkalis without staining, etching or degrading.

This metric is tested by applying standardised concentrations of each chemical type to the tile surface for a set period and rating the result as unaffected, slightly affected or affected. Glazed and unglazed surfaces are assessed and classified separately.

  • Rated against household chemicals, pool chemicals and acids/alkalis
  • Classifications: UA (unaffected), UB, UC (affected) for glazed surfaces
  • HA, HB, HC for unglazed

In commercial practice it is a primary specification requirement in environments where tiles are regularly exposed to aggressive substances.

Examples include commercial kitchens with acidic food residues, swimming pools with chlorine and pH adjustment chemicals, laboratories, pharmaceutical manufacturing and healthcare facilities using industrial cleaning and disinfection regimes.

A tile that passes slip resistance and abrasion testing but fails chemical resistance will have its surface progressively destroyed by the cleaning products used to maintain it, which is a particularly common and avoidable specification failure in healthcare and food production environments.

Standard: BS EN ISO 10545-13 (glazed), BS EN ISO 10545-14 (unglazed)

Coefficient of Thermal Expansion

Coefficient of thermal expansion measures the rate at which a tile expands and contracts as temperature changes. It is expressed in mm per metre per degree Celsius.

  • Determines joint spacing requirements and movement joint placement
  • Expressed in mm/m/°C

In commercial practice, coefficient of thermal expansion matters primarily for movement joint design, because a tile that expands significantly under underfloor heating or direct sun exposure will build up compressive stress across the installation if insufficient movement joints are provided. Eventually, this can lead to tenting or debonding.

This metric is also relevant where tiles are fixed adjacent to or onto materials with very different expansion rates. For instance, porcelain onto a steel substrate or natural stone against aluminium framing. That’s because differential movement between materials will work fixings and adhesive bonds loose over time.

Standard: BS EN ISO 10545-8

Colour and Appearance Consistency

Colour and appearance consistency describes how much variation exists between individual tiles within a production batch and between separate batches.

This metric is assessed visually and is expressed as a shade variation code (V0-V4).

V0 - Uniform appearance, no visible variation between tiles

V1 - Minimal variation, slight differences within a consistent overall colour

V2 - Moderate variation, clearly distinguishable differences between tiles within the same colour range

V3 - Substantial variation, significant colour and tonal differences between individual tiles

V4 - Random variation, each tile is essentially unique with no expectation of consistency between pieces

In commercial practice, colour and appearance consistency is most consequential on large projects where tiles are ordered across multiple batches or delivered in phases.

For instance, a V1 tile specified for a 2,000m² retail floor that arrives in two separate production runs can produce a visibly inconsistent finished surface that is impossible to remedy without wholesale replacement.

This makes batch reference numbers, shade codes, and over-ordering from a single batch standard commercial practice on any project where appearance consistency is a client requirement.

Standard: No formal BS standard. Instead it is declared by manufacturers using the industry V-coding convention.

Crazing Resistance

Crazing resistance measures whether the glaze on a ceramic or porcelain tile will develop a network of fine surface cracks over time when exposed to moisture and temperature change.

It is tested by subjecting tiles to high-pressure steam in an autoclave which accelerates the stresses that cause crazing, with a pass or fail result based on whether the glaze surface remains intact afterwards.

  • Pass or fail result

In commercial practice, crazing resistance is most relevant for glazed tiles in persistently wet or thermally variable environments such as commercial showers, swimming pool surrounds and external wall cladding.

While crazing is initially only a cosmetic defect, it progressively allows water and cleaning chemicals into the glaze layer and eventually into the tile body. Eventually, this can undermine both the appearance and the hygienic integrity of the surface in environments where those properties are often the primary reason tile was specified in the first place.

Standard: BS EN ISO 10545-11

Frost Resistance

Frost resistance measures whether a tile can survive repeated freeze-thaw cycles without cracking, spalling or degrading. This metric is tested by saturating tiles with water and cycling them through a minimum of 100 freeze-thaw cycles. A pass or fail result will be given based on whether any visible damage occurs to the body or surface.

  • Pass or fail result

A tile that fails frost resistance testing will eventually fail in the ground, because water absorbed into the tile body expands when it freezes and physically breaks the tile apart from within.

In commercial practice, frost resistance is a binary specification requirement for any tile used externally. Additionally, in unheated internal spaces such as loading bays, car parks and covered walkways.

Standard: BS EN ISO 10545-12

Light Reflectance Value (LRV)

Light reflectance value (LRV) measures the percentage of visible light a surface reflects.

Far from purely an aesthetic characteristic, the light reflectance value can be a regulatory and accessibility requirement. This includes The Equality Act 2010, which requires reasonable adjustments for visually impaired people in non-domestic buildings.

LRV most commonly governs the contrast between floor and wall surfaces, and between field tiles and functional elements such as step nosings, door thresholds and sanitary ware surrounds.

LRV is expressed on a scale of 0 to 100:

  • 0 = absolute black (absorbs all light)
  • 100 = pure white (reflects all light)

In practical tile terms, most commercial products sit between 5 and 90. It is a photometric measurement, not a colour or finish classification, which means two tiles that look similar can have meaningfully different LRV values depending on glaze, texture and pigmentation.

Standard: BS 8300:2018

Movement Joint Requirements

While not strictly a tile performance metric, this information is a requirement in all commercial specs.

  • Internal: movement joints at maximum 4.5m centres in each direction
  • External: maximum 3m centres
  • At all structural movement joints and perimeter junctions

Standard: BS 5385 Parts 1–5, BS 8000-11

Slip Resistance

Slip resistance measures how much friction a tile surface generates underfoot in both wet and dry conditions. It is tested either by the pendulum method which drags a rubber slider across the tile surface and measures the resistance force as a Pendulum Test Value, or by the ramp method which measures the angle at which a person walking on oiled tiles loses traction 

There are two accepted methods in UK commercial specifications:

  • Pendulum Test Value (PTV) - measured wet and dry
    • PTV 36+ = low slip risk
    • PTV 24–35 = moderate risk
    • PTV <24 = high risk
  • Ramp Test (R-Rating) - DIN 51130
    • R9 = low (offices, dry areas)
    • R10 = medium (kitchens, entrances)
    • R11 = high (wet rooms, ramps)
    • R12–R13 = extreme (industrial, external)
  • V-Rating - displacement volume for barefoot wet areas (V4, V6, V8, V10)

Standard: BS 7976-2, DIN 51130, DIN 51097

Stain Resistance

Stain resistance measures how easily a tile's surface can be cleaned after exposure to staining agents. It is tested by applying a standard set of substances to the tile face, leaving them for a set period and then attempting removal using progressively stronger cleaning methods.

The result is expressed as a class from 1 to 5, where class 5 cleans with water alone and class 1 cannot be cleaned by any method.

In commercial practice, stain resistance is most relevant in hospitality, healthcare, retail food, and catering environments where tiles are regularly exposed to oils, food colouring, cleaning chemicals and foot traffic contamination.

Glazed and polished tile surfaces rated 1–5:

  • Class 5 = stain fully removable with water
  • Class 1 = stain not removable

A tile that stains permanently becomes both a hygiene and aesthetic liability regardless of its structural performance.

Polished and lappato porcelain surfaces tend to perform worse than matt or structured finishes because micro-pores opened by the polishing process act as stain traps.

Standard: BS EN ISO 10545-14

Thermal Shock Resistance

Thermal shock resistance measures a tile's ability to withstand rapid and repeated temperature changes without cracking, crazing or delaminating. This metric is tested by cycling tiles between extremes of hot and cold water and assessing the surface and body for damage afterwards. It is a pass or fail result rather than a rated scale.

In commercial practice it is most relevant in environments where tiles are regularly exposed to sudden temperature changes. For example, in commercial kitchens where boiling water or steam hits a cold floor. Also, external facades moving between sun and frost and food production or catering environments where hot wash down procedures are routine.

A tile that fails thermal shock testing will eventually crack or craze in these conditions regardless of how well it is installed.

Standard: BS EN ISO 10545-9

Tile Dimensions and Surface Quality

Governs how consistent tiles are in size, shape and flatness.

  • Length/width tolerance: typically ±0.6% or ±2mm
  • Thickness tolerance: ±5% or ±0.5mm
  • Warpage (flatness): ±0.5% of diagonal
  • Wedging and straightness of sides also measured

In practical terms these measurements matter because tiles that vary even fractionally in size or flatness will produce uneven joints, lippage and a finished surface that looks poor and potentially creates a trip hazard.

The tighter the tolerances (i.e. as found in rectified porcelain), the smaller the grout joint that can be specified and the more precise the finished installation.

Standard: BS EN ISO 10545-2

Water Absorption

Water absorption is a measurement of the tile’s porosity. It measures how much water a tile takes in when immersed. It is expressed as a percentage of the tile's dry weight.

Group: BIa

Absorption: ≤0.5% 

Common name: Porcelain

Group: BIb

Absorption: 0.5-3%

Common name: Vitrified

Group: BIIa

Absorption: 3-6%

Common name: Semi-vitrified

Group: BIIb

Absorption: 6-10%

Common name: Semi-porous

Group: BIII

Absorption: >10%

Common name: Porous

The step change that matters most in commercial specification is the boundary between BIb and BIIa. Tiles above 3% absorption are generally considered unsuitable for external use, heavy wet environments or frost-exposed applications. Anything above 6% is typically restricted to internal wall use only in commercial settings.

Standard: BS EN ISO 10545-3 / ISO 13006

Get Tile Specification Advice From Our Experts

Bring your commercial tiling project together with expertise from Parkside’s technical team. We work with architects, designers and developers to ensure that the correct tiles are specified for commercial tiling projects.

Please contact us via our contact form or give us a call on 0116 276 2532 to find out more.

Or, you can visit us in person at any of our design studios located in Glasgow, Manchester, Leciester and London.

At Parkside, we also provide technical tile services including pendulum testing, LRV testing and quality testing.