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Ceramic & Porcelain Tile FAQ

Q. What is the difference between standard “ceramic” tiles and porcelain tiles?


Tile terminology can be confusing. Most types of tiles that are made from clay or a mixture of clay and other materials, then kiln-fired, are considered to be a part of the larger classification called “Ceramic Tiles”. These tiles can be split into two groups, porcelain tiles and non-porcelain tiles. These non-porcelain tiles are frequently referred to as ceramic tiles by themselves, separate from porcelain tiles.
“Ceramic” or non-porcelain tiles are generally made from red or white clay fired in a kiln. They are almost always finished with a durable glaze which carries the color and pattern. These tiles are used in both wall tile and floor tile applications, are softer and easier to cut than porcelain, and usually carry a PEI 0 to 3 rating. Non-porcelain ceramic tiles are usually suitable for very light to moderate traffic and generally have a relatively high water absorption rating making them less frost resistant and they are more prone to wear and chipping than porcelain tiles.
"Porcelain" tile is a tile that is generally made by the dust pressed method from porcelain clays which result in a tile that is dense, impervious, fine grained and smooth, with a sharply formed face. Porcelain tiles usually have a much lower water absorption rate (less than 0.5%) than non-porcelain tiles making them frost resistant or frost-proof. Glazed porcelain tiles are much harder and more wear and damage resistant than non-porcelain ceramic tiles, making them suitable for any application from light traffic to the heaviest residential and light commercial traffic. Full body porcelain tiles carry the color and pattern through the entire thickness of the tile making them virtually impervious to wear and are suitable for any application from residential to the highest traffic commercial or industrial applications. Porcelain tiles are available in matte, unglazed or a high polished finish.


Q. Can ceramic tile be used outdoors?


To be used outdoors, we recommend the tile must be frostproof and unglazed for floor use. Make sure the absorption rate is 0.5% or less.


Q. What is the difference between glazed and full-body tiles?


Glazed tiles are coated with a liquid glass, which is then baked into the surface of the clay. The glaze provides an unlimited array of colors and designs as well as protects the tile from staining. The unglazed tiles are pretty much the same as the glazed tile, except that their surface is not coated. Full-body porcelain tiles do not show wear because their color extends throughout the tile, making them ideal for commercial applications.


Q. Should a sealer be used on ceramic tile?


A glazed tile is already stain proof, so there is no purpose to putting on a sealer. You may put a penetrating sealer on your unglazed tile or your grout joints. The penetrating sealer is an invisible, stain resistant shield that is absorbed into the surface.


Q. How many tiles do I need?


Tiles are usually sold by the square feet, so the area to be tiled needs to be carefully measured to establish how many square feet are involved.  This can be done by your architect, builder or preferably your tile setter.   Note that there is always a degree of “wastage” resulting from the cuts required to achieve your tile layout.  The contingency allowance for wastage is best estimated by your tile setter, but is typically between +5% and +15%, depending on the tiles being used and the complexity of the particular design and layout. Also, consider that it is always wise to keep several spare tiles just in case replacements are required at a later date.


Q. Where can your tiles be used and what is a PEI rating?


PEI classes range from 0 to 5. The Porcelain Enamel Institute rating scale is not a measurement of quality. It is a scale that clearly indicates the areas of use each manufacturer recommends and has designed their tile to fit. A PEI 2 tile has been designed for areas where very low traffic and soiling is anticipated. In most cases the aesthetic detailing of these tiles is of prime consideration. You will often find high gloss levels, vibrant colorations and metallic elements in this group of tile. Conversely, a PEI 5 tile has been designed for abusive extra heavy foot traffic. The technical aspects such as surface abrasion resistance will be considered and must be achieved first before aesthetic effects are incorporated:

 

Class 0 - No Foot Traffic

Wall tile only and should not be used on floors.

 

Class 1 - Very light traffic:
Very low foot traffic, bare or stocking feet only. (Master bath, spa bathroom).


Class 2 - Light Traffic:
Slipper or soft-soled shoes. Second level main bathroom areas, bedrooms.


Class 3 - Light to Moderate Traffic:
Any residential area with the possible exception of some entries and kitchens if extremely heavy or abrasive traffic is anticipated.


Class 4 - Moderate to Heavy Traffic:
High foot traffic, areas where abrasive or outside dirt could be tracked. Residential entry, kitchen, balcony, and countertop.


Class 5 - Heavy Traffic:
Ceramic tile suggested for residential, commercial and institutional floor subjected to heavy traffic.


Q. How much breakage should I expect with an order?


A. It is not unusual to have 2% - 3% of the tile broken to some degree (e.g. chipped edges). Any amount up to 10% is still considered acceptable. These damaged tiles can be used for the cuts you will need to make. If breakage is above 10%, we would ask you to have it noted on the logistics receiving document and take pictures. Please make a claim with us within 10 days of receiving the order.


Q. What are “rectified” tiles?


All natural tiles vary slightly between production runs.  Sizes change between “batches” and this means that mixing & matching different production batches is seldom possible.  “Rectified” tiles are deliberately made over-size, and are then cut on a diamond saw at the factory to a common caliber.  The square, saw-cut edges allow for finer (narrower) grout joints between tiles and result in a beautiful and contemporary finished look.  Rectified calibration also means that rectified tiles will still work together when modular sizes are mixed.  Rectified products have increased in popularity over recent times.  Note that rectified tiles need to be installed on a good surface (square & level), and your tile setter should be experienced with the requirements for laying this kind of product.

Q. What is the difference between wall and floor tiles?


Wall tiles (because they are not intended to be load bearing) are typically thinner, lighter and softer than floor tiles.  Wall tile glazes are not designed to handle the abrasive forces from foot traffic. Increasingly, floor tiles are being applied to walls and this is no problem so long as the walls are strong enough to support their weight and proper ceramic tile installation methods are used. However, it is not usual to recommend using wall tiles in floor applications.