Porcelain & Natural Stone Guide

What is a Limestone?

Limestone is a sedimentary rock, formed over millions of years. A combination of sediments, broken seashells, coral and the remains of aquatic animals deposited on the waterbed, slowly compresses over time into a hard rock. Whilst the process is largely the same, the characteristics and colours between limestones can vary, as can the density.

What is a Marble?

Marble is a metamorphic rock formed by the alteration of limestone by heat and pressure (thermal metamorphism). Depending on the point of extraction, some marbles can look very similar to limestones. Generally speaking, a marble tends to be a dense, closed tile due to the process of metamorphism. However, it is also common practice for resin to be applied to occasional voids and open veins.

Natural Stone - Variation & Characteristics

The beauty of natural stone lies within its variation - no two tiles are ever the same. We have worked closely alongside our suppliers for over twenty seven years to ensure we select and import the stones we know our customers love.

When considering a natural stone floor, it is important to acknowledge the geological characteristics natural
stones showcase; these include tonal variation, veining, fissures, oxidisation, crystallisation, surface pits and edge chipping.

We go to great lengths to showcase the variation to be expected, this includes; large grouted showroom displays, a complimentary sample service, and extensive online imagery; we take great pride in photographing customers finished projects to show an array of batches from the same material - celebrating the uniqueness natural stone flooring offers.

Due to the nature of natural materials, a degree of variation is beyond our control and will occur from project to project.

Are Natural Stones UV Sensitive?

Over the years, natural stone tiles can lighten in colour when installed externally.

Porcelain tiles are UV stable and will not lighten in colour.

What is a 'Blend' Limestone?

The Blend selection of limestones is currently available in two ranges (Dijon Blend & Farrow Blend).

The Blend is the commercial selection of the stone and does not meet the aesthetic grading required for premium selections. Whilst all natural stones can feature tonal variation, fossils, calcite veining, fissures, pitting, oxidisation, and crystallisation – the Blend selections will display a much higher percentage of these features, resulting in an aged, rustic looking floor.

The Blend selections are made up from multiple batches, it is therefore imperative that the stones are graded prior to installation to ensure the best application. We recommend viewing this stone at one of our showrooms to ensure its suitability for your project.

We recommend ordering between 15-20% wastage for Blend ranges to allow for flexibility when choosing tiles to be used for cuts.

French Limestone

Due to the artisanal craftmanship involved in achieving the finishes of French Limestones, these stones are available on a 'to order' basis and are not a stock item.

For this reason, we are unable to offer hand sized samples. Instead a 200 x 200 piece can be purchased for £12 on the product page.

The lead time for French Limestone is approximately 8-12 weeks (this can be longer during busy periods).

What is a Porcelain Tile?

A porcelain tile is a man-made product that combines kaolin clay, finely ground sand and feldspar. Some of our porcelain tile ranges are made up of 40% recycled materials.

The clay mixture is fired to an extremely high temperature, upwards of 1200 degrees, resulting in a very dense tile that benefits from a low water absorption rate – typically this stands at 0.5% or less.

Porcelain is a great option for busy homes as it is durable and requires little maintenance (in most cases there is no sealing necessary).

The majority of porcelain ranges are available in both an internal and external tile.

Porcelain - R Rating & ABC Rating

Porcelain tiles are tested for their ‘anti-slip’ qualities by the means of a ramp test and barefoot ramp test. The DIN 51130 and DIN 51097 are established worldwide test methods within the tile industry.

An R rating is given based on a ramp test whilst wearing shoes and an ABC rating is given based on a barefoot ramp test usually with the tiles coated in water. These ratings are more relevant to commercial applications, but it can be useful to guide decisions for domestic use.

We recommend R9/R10 for internal use and an R11 finish for external use. All porcelain paving comes in an R11 finish as standard.

The ABC rating is useful to know the suitability of a tile especially for wet rooms and bathrooms:

C (A+B+C) – strongest level of slip, best for commercial wet areas etc. 

B (A+B) –suitable for wet room floors and outdoors

A - suitable for most indoor uses such as kitchens and hallways

Porcelain - Rectified vs Non-Rectified

Rectified Tiles

Rectified tiles are produced in the same way as non-rectified tiles, except that the clay is moulded slightly bigger than necessary. Following the firing process, rectified tiles are then cut or ground down with a diamond saw to within a very precise tolerance.

This is known as the rectifying process and allows a fine grout joint to be achieved during installation. The tolerance can vary slightly between production runs and therefore any one project should be completed with tiles from the same batch/production run.

Non-Rectified Tiles

Unlike rectified tiles, non-rectified tiles are not cut or ground down after the firing process. Due to the shrinkage that can occur during the firing process, it is normal to expect slight variation between the sizing of each tile vs a rectified tile. To accommodate this, it may be necessary to make the grout joint slightly wider.

Typically, non-rectified tiles are patterned or glazed tiles whereby the rectifying process would affect the look of the finished tile.

Porcelain - PEI Rating

A PEI rating is given to a glazed tile to show its resistance to abrasion. The rating is carried out in line with standards from the Porcelain Enamel Institute. The PEI rating of a glazed tile can range from 1-5.

Group 1 Suitable only for residential / commercial walls. Not suitable and/or recommended for foot traffic. examples include bathroom walls, backsplashes and accent walls

Group 2 Suitable for general light residential traffic. examples include bathrooms, formal dining rooms, formal living rooms, etc. NOT suitable for residential areas subjected to continuous foot traffic.

Group 3 Suitable for all residential and light commercial areas. examples include residential kitchens, foyers, laundry rooms, commercial offices, reception areas and boutiques

Group 4 Suitable for residential, medium commercial and light institutional applications. examples include restaurants, hotels, hospital lobbies and corridors

Group 5+ Suitable for heavy traffic in both residential and heavy commercial applications. examples include mass transit, airports, malls, schools, etc.

Porcelain - Variation & Characteristics

The variations and features to be expected in porcelain depends on the range. Some ranges are contemporary and display little to no variation from tile to tile, whilst other ranges provide a stone like appearance and can therefore mimic veining, fossils and oxidisation.

The product page will advise the level of variation the range has.

Natural Stone vs Porcelain Tiles

Both natural stone and porcelain provide hard wearing, practical options for modern day living. The above chart runs through the differences of each material so you can decide which will suit your project and lifestyle best.

Tile Batches

Both natural stone and porcelain are produced in batches. Due to the nature of the products; tonal, textural, and nominal changes in size can be expected between batches.

We cannot guarantee that subsequent orders will be from the same batch and therefore recommend ordering our suggested wastage or more.