Tile is one of those things that looks simple until you've watched it go wrong. A tile job can look great the day it's finished and still have real problems underneath, ones that don't show up until months or years later, when they're far more expensive to fix than they would have been to do right the first time.

After a decade in the trades, with tile work as my specialty, these are the five pitfalls I see most often,
the kind that separate a tile job that lasts decades from one that needs to be redone within a few years.

1. Not Checking Dye Lot or Batch Consistency

Tile is manufactured in batches, and even tile that's the exact same product name and style can have visible color variation from one batch, or "dye lot," to the next. Order enough tile for a job across two different batches without checking, and you can end up with a floor or wall that has a noticeable, uneven color shift right in the middle of it or delay the job for weeks.

What to do instead:
Always check the dye lot number on the boxes before installation, make sure enough tile from the same lot is ordered for the entire job - including a reasonable overage for cuts and waste. If a job requires ordering more tile later a lot mismatch is a real risk worth flagging before installation, not after.

Years ago, I was part of a crew that installed all the tile in a Lake House of a well known industry titan and his tile designer got 2 sample tiles, let me repeat that, 2 individual pieces of marble to decide whether to order the $60,000 worth of tile for the shower stall.  Let's just say the tile didn't come out of the same side of the mountain!  All 5 pallets of special order Carrera Marble had to be shipped back overseas and not for free!  Not only did it cost a substantial amount of money, but delayed the job for 2 months.

2. Using the Wrong Trowel Size for the Tile

This is one of the most common causes of a problem called lippage, where the edge of one tile sits slightly higher than the tile next to it. It's a small difference, sometimes just a millimeter or two, but it's very noticeable underfoot and to the eye, and it becomes a real trip hazard over time. Lippage usually comes down to using the wrong notched trowel size for the tile being installed, which means the tile isn't getting properly, evenly bedded into the mortar underneath.

What to do instead:
Trowel size should match the tile size and type, larger format tile generally needs a larger notch trowel to ensure full, even mortar coverage. This isn't a place to guess, it's a specification that should match the tile manufacturer's recommendation.

3. Skipping Proper Backer Board and Substrate Prep

Tile needs a stable, appropriate substrate underneath it, not just whatever surface happens to already be there. Installing tile directly over drywall in a wet area, or skipping cement backer board where it's needed is a shortcut that often looks fine on installation day and starts cracking within the first year as the substrate flexes or absorbs moisture in ways tile can't handle.

What to do instead:
Make sure the substrate is appropriate for the location, cement backer board in wet areas, properly prepped, waterproofed and leveled subfloor for floor tile before any tile goes down. This step is invisible in the finished product, which is exactly why it's the step some installers are tempted to rush.

Most customers and sadly some installers never consider that finish work starts at the rough in.  For example, if you don't build the wall square and plumb you'll see it in the tile when your done!

4. Inconsistent Grout Line Spacing

Uneven grout lines are one of the fastest ways a tile job reads as amateur, even when the tile itself is high quality and expensive. This usually comes down to not using tile spacers consistently, or rushing the layout without properly planning where cuts and lines will fall before starting. This becomes explicitly apparent when using artisan tile as they are never the same size. Many amateur installers can get away with standard dimensional tile, but when you get into handmade Moroccan or artisanal clay tile from Wisconsin there inexperience shows!

What to do instead:
Consistent spacers throughout the job, and a real layout plan before the first tile goes down.  As well as establishing where the pattern starts and finishes so cut tiles at the edges of a room look intentional rather than like an afterthought.

5. Not Sealing the Grout

Grout is porous by nature. Without a sealer it soaks up moisture and stains from everyday use, and in a bathroom specifically, that means darkening, discoloration, and water working its way through faster than most homeowners expect. It's one of the most common tile-related complaints I hear, and one of the easiest to have prevented in the first place.

What to do instead:
On a new installation, this is genuinely one of the simplest mistakes to avoid, sealer doesn't have to be a separate step applied after the fact. A sealing additive can be mixed directly into the grout at the time it's installed, so proper protection is built in from day one instead of relying on someone remembering to seal it later.  Another pro tip is to re-seal it on schedule after that, usually every other year.

​A good tile job should last decades, not years. If you're planning a tile project and want it done in a way that actually holds up, feel free to reach out.