Porcelain tiles are harder than ceramic and glass tiles. It is actually unfair to compare glass and porcelain. Porcelain and ceramic tiles cannot be compared in a generic manner because the former is a subtype of the latter. Porcelain is a kind of ceramic tile. The composition of an ordinary ceramic tile can be identical or very similar to that of a porcelain tile. However, a porcelain tile is exposed to much higher temperatures than what ordinary ceramic tiles are fired at. This process is significant because it is the most consequential difference. The exposure to higher temperatures increases the density of the minerals in porcelain tile and hence the material becomes much more nonporous. Kitchen tiles have to be nonporous. They may not have to be as nonporous as those in the bathrooms but must be as close as possible.
While porcelain tiles are more nonporous than standard ceramic and even other commonly used materials, there are variants. Porcelain tiles are classified into five categories based on their porosity. Impervious porcelain tiles are the most nonporous among all types of porcelain. You should buy impervious porcelain tiles for your bathroom, kitchen and other utility areas that will get exposed to a lot of water or moisture. Vitreous porcelain is the next best choice. While impervious allows water absorption of less than 0.5%, vitreous allows up to 3%. Semi vitreous allows more than 3% and up to 7%. Semi vitreous porcelain is suitable for living rooms and bedrooms but not as kitchen tiles, definitely not for bathrooms. Non vitreous porcelain is a nonstarter. It allows water absorption of over 7%.
Such classifications are not unique for porcelain. Other tiles will also have varied levels of porosity and you must factor this attribute while choosing kitchen tiles. Porcelain kitchen tiles are more expensive than ordinary kitchen tiles but there isn’t a huge difference. Porcelain tiles come in diverse designs and styles. There are some treatments available too. You should go for glazed porcelain kitchen tiles.
There is something you should know about porcelain that is not applicable to other ceramic kitchen tiles. Porcelain is a nonporous material compared to ordinary ceramic. Normal adhesives do not work well with such a material. Porcelain needs a special adhesive. It is usually recommended by the manufacturer. Do not use any other adhesive than the one recommended for your porcelain kitchen tiles.