When picking out your tile how do you make sure that the surface is durable enough to last in that particular area? Well, being a hands-on kinda guy I use to walk into the tile shop with a belt sander and test it. If the sandpaper wore out before the surface of the tile we found a winner! This tended to piss people off, though. Then I found out there is, as most things I do, an easier way.
For everyone else in the world this is determined by using what is called the PEI, or Porcelain Enamel Institute, rating of your tile. The PEI rating is between I and V with a V being the most durable. Those are Roman numerals, not the 19 letters between I and V. 
I’ll just call them 1 to 5 – you know, since I’m not from, nor am I in, Rome.
This scale is used by most tile manufacturers to determine the surface wear durability and should be printed on the box of tile somewhere. If it is not you can always contact your tile manufacturer for the information.
General guidelines for proper installation areas are as follows:
- Group I: Tile suitable only for residential or commercial walls – stuff you don’t walk on unless you’re Spiderman. Not suitable or recommended for foot traffic (unless you are, indeed, Spiderman).
- Group II: Tile suitable for general light residential traffic. Not recommended for kitchens, entryways, heavily used bathroom floors or any other area subject to continuous use foot traffic.
- Group III: Tile suitable for all residential and light use commercial foot traffic areas. You can pretty much put this everywhere in your house except your garage floor.
- Group IV: Tile suited to all residential, medium commercial, and light industrial applications such as restaurants, hotels, and hospital lobbies.
- Group V: Tile suitable for all residential, heavy commercial, and industrial applications such as airports, malls, subways, and the Space Shuttle.
The particular group number or PEI rating is a measure of the durability of the tile surface only. It does not determine the slip resistance, overall strength, moisture absorption, or quality of the tile itself, only the quality and durability of the surface or glaze. For most residential flooring applications it is always best to go with a PEI rating of three or higher, although a two is suitable for some applications.
By taking the PEI rating into consideration when choosing your tile you can ensure you have a properly durable tile for your particular installation.
The PEI rating is only one aspect to consider when choosing your tile. There are a few others which must be taken into account for an overall proper tile choice. These include the Mohs hardness, density of the tile, absorption rate, the Static Coefficient of Friction (S.C.O.F.), and the most important aspect – does your wife like the way it looks?
You can always simply walk in someplace and pick out a tile without utilizing the available information, however, taking advantage of the different rating systems ensures a proper choice for lasting durability of your tile installation.
Or at least take a belt sander with you.
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Would like suggestions on flavor of tiles. I am putting it in a heavy traffic room…I will be rolling heavy parrot cages across it, the dogs will be running across it as will the children. So heavy dirt and the occasional heavy crockery thrown down. I need slip resistance and if you could suggest one that is less echoey as the cockatoo yell is loud enough without it being magnified by flooring, also one that helps solve world peace or the energy crisis.
Hi Kimberly,
You’ll need to look at a couple of different aspects of any tile you’re choosing and use the applicable numbers to determine whether or not it’s suited to your little mini-zoo.
I would suggest looking at different porcelains, a class III porcelain tile would be the way to go. The aspects of any porcelain you find that you need to pay attention to are the Mohs hardness and the COF number. You can read through my post about choosing the correct tile for an explanation of COF.
The Mohs scale is a bit trickier, the exact number doesn’t always translate to what you are looking for so it will be more relative to the overall aspects of the tile. In other words it would be the least exacting factor on which to base your decision. Mohs scales go from one to ten – the higher the number the harder the surface. Look for a porcelain around 6.8 – 7.0. A high mohs number coupled with a good COF should give you a very durable porcelain which may outlast the noisy bird.
What PEI rating, Mohs hardness, density, absorption rate and Static Coefficient of Friction would YOU recommend for a home shower?
Hi Debbie,
There are actually two different sets of numbers to consider – the vertical surfaces (shower walls) and the horizontal surfaces (anything you walk on).
The vertical surfaces would be fine with a PEI above II, a Mohs of 4, SCOF of 3 dry or wet, and an absorption rate of less than 0.5% (porcelain).
The horizontal surfaces are a bit more tricky since you’ll be walking on wet tile. I like a PEI above III, a Mohs of 4 or 5, SCOF of 4 dry, 5 or 6 wet, and an absorption rate of less than 0.5% (porcelain).
All these number are subjective, though! Marble breaks just about every one of those to a less than ideal condition, but marble bathrooms have lasted thousands of years. It is entirely dependent on your particular bathroom. How much maintenance do you want to put in? How often do you want to deep clean? How many kids do you have that will slip on it? How many pets do you have that will scratch it? Do you live near a beach where sand is a common material being grinded underfoot?
See what I mean – subjective.