Ceramic tile has been a go-to floor material for decades, and for good reason. It’s durable, water-resistant, easy to clean, and compatible with radiant heating. But the gap between a ceramic floor that looks great ten years after installation and one that shows wear, cracking, or grout deterioration in three years isn’t usually about which tile looks best in the showroom. It’s about a few purchasing decisions that get made before the tile even arrives on site.
Mistake one: buying by appearance, ignoring the PEI rating
The PEI (Porcelain Enamel Institute) abrasion rating classifies ceramic tile by its resistance to surface wear. It runs from Class 1 (decorative, walls only) to Class 5 (heavy commercial traffic). Most residential applications (kitchen floors, bathrooms, entryways) require Class 3 at minimum. High-traffic areas like open-plan main floors benefit from Class 4.
The problem: PEI rating isn’t front-and-center in most retail environments. Tiles are displayed by color, format, and price. The technical spec is in the fine print of the product sheet, which most buyers never read. Selecting a visually appealing Class 2 tile for a kitchen floor is a common mistake that becomes obvious about two years into daily foot traffic.
For floor tile specifically, a good ceramic floor supplier should be able to specify PEI class for every product they carry. If they can’t, that’s a signal about how seriously the supply chain takes technical specification.
Mistake two: underestimating dimensional tolerance and its effect on grout lines
Not all ceramic tiles are manufactured to the same dimensional tolerance. Rectified tiles are cut to precise dimensions after firing, allowing very tight grout joints (2mm or less). Non-rectified tiles have wider manufacturing tolerances and require wider joints to accommodate variation.
This matters because the width of the grout joint affects both the aesthetic outcome and the maintenance burden. Wide grout joints in a light color in a kitchen or bathroom get dirty faster and are harder to keep clean. Many homeowners who say they “hate grout” actually hate wide grout joints, which are a consequence of tile selection, not an unavoidable feature of ceramic floors.
The solution isn’t always to buy rectified tile, that comes at a cost premium and requires a skilled installer who can work to tight tolerances. But it’s worth understanding the relationship between tile quality, installation method, and the grout joint width you’ll live with.
Mistake three: ordering the wrong quantity
The standard industry recommendation is to order 10-15% extra beyond the measured square footage. This accounts for cuts, breakage during installation, and future repairs. Most homeowners accept this in principle and then quietly order exactly 10% because the extra tile feels wasteful.
But here’s the practical problem: tile comes in batches (called dye lots or calibers), and different batches of the same reference can have slight variations in color or shade. If you run short mid-installation and need to reorder, there’s no guarantee the new batch will match precisely. The result is a visible transition in the floor, sometimes subtle, sometimes not.
For large-format tiles (anything 24×24 or larger), the 15% rule is more conservative than the 10% rule for a reason: the cuts are more material-intensive and the breakage risk during handling and installation is higher. Order the extra tile. Store the leftover properly after installation. If you never use it, the cost is minimal. If you need it three years later for a repair, you’ll be genuinely glad it’s there.
What good sourcing looks like
A supplier who helps you avoid these three mistakes (provides PEI specs upfront, explains the difference between rectified and non-rectified products, and helps you calculate an accurate quantity including waste factor) is worth more than the marginal price difference between suppliers. These aren’t just product decisions. They’re decisions that will define what your floor looks like and how it holds up for the next decade.