Glazed Tile PEI (Porcelain Enamel Institute) Rating Explained

What does PEI rating mean?

Porcelain Enamel Institute (PEI) rating helps you determine the hardness and durability of your tiles. This scale was designed to help create reliable standards for consumers when choosing which tiles to use for which applications. This scale is used to measure the hardness and durability of both ceramic and porcelain tiles, but due to the natural hardness built into porcelain tiles, it is generally more applicable to ceramic.

Why is PEI important?

When it comes to choosing the right tile, it’s important to remember that not all tiles are suitable for all situations. For example, the shiny wall tiles in your bathroom would struggle with the footfall on your kitchen floor. You wouldn’t want to install a tiled floor only for it to look cracked and aged six months later. Thankfully, PEI Ratings act as a guide for discovering which tile suits your needs.

How is PEI measured?

PEI ratings are determined by a measurement of Abrasion Resistance measured on a Rotary Abrasion Resistance Testing Machine. This machine counts the number of revolutions under a standard abrasive load. The machine works by rotating steel ball bearings on the surface of a tile for a given number of rotations. When the tile shows signs of damage the revolutions are counted (from 150 to 1500+). This gives the PEI rating.

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What are the different PEI ratings?

PEI is measured on a scale of 1 to 5, with 1 being the weakest and least durable and 5 being the strongest and most durable.

Class 1 - This is the weakest of all standard grade ceramic tiles and should never be used underfoot. Suitable for wall applications only.

Class 2 - Can be used on residential interior floors but should not be used in areas such as kitchens, entryways, and stairs that are subject to a high footfall.

Class 3 - Can be used for any residential or light commercial application. The only place that they are not recommended is in heavy traffic commercial areas, like banks and restaurants.

Class 4 - Can be used for any residential and most commercial applications. These tiles are durable enough to be used in such heavy traffic areas as shopping malls.

Class 5 - The most durable and can be used for all residential, commercial, and even industrial applications where extreme durability is a must.



Stay informed about PEI ratings by learning how Kastus Ceramics allows you to achieve a ceramic tile surface of PEI rating 4 or greater!

Increase Ceramic Floor Tile PEI Rating with Kastus

Kastus Ceramics is a glaze that can achieve a PEI (Porcelain Enamel Institute) rating of 4 or greater for your floor tile surface, regardless of tile color. Ceramic tile manufacturers are challenged to create products that are safe and superior to competitors. The aim is to produce a technically sound tile with high scratch, stain and abrasion resistance, while also being aesthetically pleasing, durable and cost-effective. Many have aspired, tried and failed to create such a product. That is, until now. Until Kastus.

What is the PEI rating and how is PEI determined? In summary, the PEI rating is an indication of tile hardness. It’s one factor that helps to determine if a tile is sufficient for a project. For example, a PEI rating of 4 means a ceramic floor tile is suitable for all residential applications as well as medium commercial and light institutional use.

We’ve worked for over 10 years to develop a multi-purpose glaze that adds value to ceramic tiles, through enhanced physical and biological functionalities. Kastus Ceramics is an ISO certified solution that creates life-long stain and scratch-resistance on the tile surface.

By now, you know that floor tiles featuring Kastus Ceramics glaze are tougher than the average ceramic tile. However, that’s only useful if consumers can still benefit from elegant, beautifully-designed tiles. Well, they can.

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Does Kastus Ceramics affect the appearance of tiles?

Kastus Ceramics spray does not interfere with the tile appearance in any way. What if the tiles are black or another dark color? Regardless of the tile color, Kastus Ceramics does not interfere with the tile appearance in any way. The glaze is sprayed onto the ceramic surface prior to firing and sinters onto the surface. This leaves a clear, invisible finish so that your beautifully-designed ceramic tiles keep their uniqueness while gaining all the benefits of Kastus technologies.


In short, Kastus Ceramics glaze is a value-adding technology. It allows ceramic floor tile surfaces of all colors to achieve a PEI rating of 4 or greater, as well as additional benefits. To know more about Kastus Ceramics’ ISO testing and PEI ratings, read the Kastus Ceramics Technical Certification document.

Imagine a World Free from Bacteria

Superbugs, also known as drug-resistant bacteria, are one of the biggest threats facing humanity today. For almost a century, we have used antibiotics to fight off disease, but these antibiotics are starting to lose their punch as Superbugs learn how to beat them.

Kastus is an Irish company that has developed a pioneering technology in the fight against superbugs. It’s a water-based solution which, when applied to any surface material, uses natural light to prevent the growth of harmful bacteria on that surface. Alternative antimicrobial solutions require UV light and leach harmful chemicals into the environment to be effective. However, Kastus’ solution is always active in the presence of natural light and it is environmentally friendly.

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John Browne, Kastus Founder says: “Every time you open a door, answer a phone, touch a wall, sit on a toilet, wash your hands, walk barefoot on a tiled floor, brush against a ceramic or glass surface, you are in danger of spreading or picking up bugs and germs with the potential to make you sick – or worse.”

The Irish government estimates that by 2050, antibiotic resistance will kill more than 10 million people a year, making it a bigger killer than cancer. The rise of superbugs and the fall in the effectiveness of antibiotics has become a global issue at the highest levels.

Kastus’ technology is a significant breakthrough in the battle against Superbugs and the real-world demand and applications for its solutions are vast. Want to read about our tech? Find out exactly how Kastus technologies work.

Mejore el PEI de la cerámica con KASTUS

Kastus Ceramics es una solución a base de agua que posibilita el alcance de un PEI (Porcelain Enamel Institute) de 4 o superior en la superficie del revestimiento cerámico, independiente de su color. Fabricantes de revestimientos cerámicos han sido constantemente desafiados a idealizar y desarrollar productos más fuertes y superiores a los de la competencia. El paradigma es: producir un revestimiento cerámico con alta resistencia a rasguños, manchas y productos químicos, que al mismo tiempo sea estéticamente agradable, durable y costo-efectivo. Como muchos paradigmas, este también ha durado por siglos y los intentos para romperlo han costado el esfuerzo de muchos profesionales y millones de dólares en inversión. Este paradigma ha sido roto. Ha sido roto por KASTUS.

¿Qué es la clasificación PEI y como el PEI es determinado? En resumen, la clasificación PEI determina la resistencia a la abrasión superficial de la cerámica. Es un factor clave para determinar el revestimiento cerámico ideal para utilizar en cada proyecto. Cuanto menor sea la clasificación PEI, menor su resistencia, siendo el mínimo 0 y el máximo 5. Un revestimiento cerámico de PEI 4 por ejemplo, presenta una resistencia a la abrasión alta, luego puede ser utilizado en áreas de circulación intensa de personas y en locales abiertos al público, pero con circulación moderada.

Tras 10 años de investigación científica la fórmula de KASTUS alcanzó la combinación perfecta de sus elementos, proporcionando a la cerámica un grupo de beneficios únicos a nivel mundial. La solución KASTUS CERAMICS posee certificación ISO que apoya todas las funcionalidades agregadas a la cerámica en el más elevado standard internacional.

Por ahora, usted ya sabe que la solución KASTUS CERAMICS mejora las propiedades mecánicas y biológicas de su producto. Mientras tanto, eso solamente puede ser provechoso si los consumidores puedan disfrutar de esos revestimientos cerámicos elegantes y con design atractivo. Bueno, eso es posible.

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¿KASTUS CERAMICS afecta la apariencia del revestimiento cerámico?

La solución KASTUS Ceramics no afecta la apariencia del revestimiento cerámico de ninguna forma, independiente de su color. La solución es aplicada en la superficie del revestimiento cerámico después del esmaltado y antes de la cocción. Después de la cocción, lo que se ve es un revestimiento cerámico con su design y brillo intactos, preservando su identidad única, pero ahora con un grupo extraordinario de beneficios impulsados por KASTUS.


Kastus es una solución tecnológica-industrial que valora su producto. Ella permite que la superficie de un revestimiento cerámico de cualquier color alcance un PEI de 4 o superior, así como varios otros beneficios. Para saber más sobre las certificaciones internacionales ISO y la clasificación PEI de Kastus Ceramics, por favor vea el documento técnico de certificación disponible más abajo.: Kastus Ceramics Technical Certification document.

New developments by Kastus in commercialisation of its innovation

Kastus, an Irish company responsible for the creation of a ground-breaking technology to prevent the spread of superbugs, has announced the closure of a €3 million venture funding round, and significant new developments in the commercialisation of its innovation.

“We should have the funding in place next month, and it will enable us to hire a significant number of new people to work with us on the scaling of the company and the technology,” says chief executive John Browne.

“Scaling is really about people. We are hiring a mix of technical, sales, marketing, development and back-office staff. We already have a very good R&D team, and we are expanding our sales and marketing team at the moment.”

The Kastus product is an antimicrobial spray coating which can be applied to glass and ceramics during or after manufacture or added to plastics and paint. It can be used to protect a range of high-touch everyday surfaces – including ceramic and glass tiles, smartphones, glass, door handles and metals – from harmful bacteria and micro-organisms such as MRSA and e-coli.

The coating has a proven kill rate of up to 99.97% against harmful bacteria, fungi and antibiotic-resistant superbugs, which makes it particularly useful for products such as ceramic tiles and glass which will be used in hospital or other settings where hygiene is at a premium

It is also the first product of its kind that can be factory applied on everyday hard surfaces using no toxic bi-products. Previous antimicrobial solutions needed UV light or biocide chemical leaching to be activated, but Kastus’s products are activated by indoor light and environmental moisture.

Growth paths

The 2017 Irish Times Innovation Awards Winner has identified a number of growth paths. “Our whole commercial focus is international,” says Browne. “We are not looking for any sales on the domestic market. Our whole focus in on original equipment manufacturers in Europe, the Middle East and the US. We are targeting the international glass and ceramics industries in the first instance, and will grow from there. Our technology adds value to their products – it gives them anti-microbial properties, makes them easier to clean, and makes them longer lasting.”

The company also recently announced a collaboration with Amber, the Science Foundation Ireland (SFI)-funded materials science centre at Trinity College Dublin, which will involve specialised research work on the further development of antimicrobial coatings. The €280,000 research programme will see two academic experts in science and engineering join Kastus from Amber under the SFI Industry Fellowship Programme.

The collaboration has the potential to significantly impact how MRSA and other superbugs are controlled and prevented in hospital and community settings, according to Amber director Prof Michael Morris.

“This is an exciting move for Kastus, and demonstrates the links that we are continuing to forge with academia,” adds Kastus’s director of innovation and operations Dr James Kennedy. “We are already working with Crest [Centre for Research in Engineering Surface Technology] at the Dublin Institute of Technology, and believe that collaboration between academic research and industry is key to major breakthroughs in technology.”


Browne believes those collaborations offer a potentially rich seam of new technologies for the company to commercialise.

“We are starting to cast our net out to the third-level institutions to see if they have complementary technologies to ours which we can help bring to market. There are a lot of technologies and bright ideas in the third-level institutions which tend to stay in the lab because the people involved are not commercial animals.

“We know from experience that it’s a long, hard and expensive road to commercialise a technology, and we want to collaborate with them on this. We have already identified two technologies that we are working on.”

In terms of the core product, he says the intention is to become more selective in the sales effort.

“When you’re a start-up you can be a bit like an excited labrador chasing leaves around the garden. We have to guard against that, and refine our sales process to become a bit more choosy. We want to work with people who understand and appreciate the commercial advantages and the value-add that our product offers.”