Ceramic vs porcelin

Hi Willy,

I'd love to know the answer to this also! From what I have read (choice, etc) there is not a lot of difference between ceramic and porcelain - apart from personal preference.
We had a look at a tiling place yesterday and noticed that almost all of the ceramic tiles had a wear rating of 3, whereas the porcelain were 4 or 5... didn't get a chance to ask exactly what this means, but I'm guessing the higher the wear rating, the stronger the tile. If laid onto a concrete slab I don't see that it could move that much (unless your concrete slab cracks). My parents have been in their place for almost 25 years, and they have ceramic tiles, and in one spot near a corner there is a fine hairline crack in the tiles - but it's not very obvious. I'm sure you'd get some sort of movement effects no matter what you choose.
I personally love the look of minimal grout with large tiles, and I love the square edge you seem to only be able to get with the porcelain. All of the ceramic ones we saw have a somewhat rounded edge, which is going to mean more visible grout.

Ray.

This may or may not be true. I understand that there are 2 types of porcelain tyles - glazed (the same as ceramic; just a coating of the colour on top) and vitrified (same colour all the way through). Only the vitrified would show less chip marks, but even then if the surface is gloss, the chip will not be. You should be able to see which the tile is by looking at the side of it.

Ray.

Oh, on the rating, I understand from some tilers that a rating of 2-3 is sufficient for general living area. The higher the rating, the harder it is. Usually 5s are commercial grades.

Many terms used to described tiles are interchangeable and mean different things to different people, and that includes retailers and professionals. To make things really confusing, if you took say 3 tiles with quite different qualities to a dozen professionals in the tile industry, you may get a range of descriptions when they are asked to ID them. And they may not necessarily be wrong! So now that you are utterly in the dark, lets cut through all this and look at some basic thruths......

Technically, porcelain tiles are ceramic tiles, and most tiles share the same basic qualities (they are clay, formed and fired) yet there are endless variaties. The main difference with porcelains is the quality of the clay used. Porcelain tiles are made from a much higher quality, finer and denser clay known as kaolin clay. It offers a much more durable, hard wearing surface than cheaper tiles. Generally, porcelains will be more expensive.

So, tiles may be made very crudely, by simply digging clay out and spreading into a timber frame and drying in the sun (like mexican saltillo terracottas) or made in hi-tech manufacturing plants from the choicest clays, fired in ovens at extreme temperatures in machines to high tolerances. Ceramic basicly means a clay that is fired. Glass is ceramic.

In general terms though, most people refer to ceramic as being a glazed tile with a surface that is fired to produce a hard non-porous surface. Porcelains can be the same, but with higher quality kaolin clay used. Then there are polished porcelains that have a honed or polished surface. These are often made to stringent dimentional tolerances and to exacting specifications. They have a flat smooth shiny face with machined edges making them suitable for laying with very narrow grout joints, providing an almost seamless appearance. So, a benefit of porcelains is that there's very little grout to soil. In high quality installations, epoxy grout is used that is waterproof and has excellent stain resistance so gives a fine surface.

IMPORTANT NOTE: Most polished porcelains are somewhat porous due to the honed surface having 'cut' the grain of the tile body, so they are NOT stain resistant. To give good service it is highly recommended that the following procedures are performed when tiles are layed;

1. Most porcelains have a factory applied wax or finish applied at the factory before packing. This must be cleaned off by a professional tile cleaning service.
2. A quality solvent based penetrating sealer should be applied to seal the tiles and provide stain-resistance.

NOTE: The costs of these two procedures will add significantly to the cost of a tile installation, so be prepared for the $$$ a polished porcelain installation will cost. It is a high class beautiful surface if its what you want, but it will cost you!

Becoming more common these days are a range of textured porcelains. in general terms they are vey good tiles, but there are just too many variables to go into here.

In short..... take your time, decide what finish and service YOU WANT from a floor, shop around, buy carefully, and maintain it well.

Regarding the original question about porcelains cracking, that should not be the case with a quality laid product, as long as the pad has properly cured and settled. Movement in a subsurface can cause any tiles to crack and porcelains are not any more prone.

Ash.