Guide
Tile Tenting & Lippage: What Causes It, Is It Urgent?
A tile floor that suddenly has a raised ridge or a bump that looks like it's pushing upward is usually either tenting or lippage. They're related problems with different urgency levels, and telling them apart matters for deciding how quickly to act.
Request ServiceWhat tenting actually is
Tile tenting happens when two adjacent tiles lift off the subfloor and press against each other, creating a tent-shaped ridge along the seam. It's caused by built-up pressure with nowhere to release, and it's considered a genuine safety concern because a tented tile can crack or shatter suddenly under foot traffic.
What lippage actually is
Lippage is different: it's when adjacent tiles sit at slightly different heights, so an edge is noticeably higher than the tile next to it. It's more often a trip hazard or a cosmetic issue than a sudden-failure risk, though severe lippage can still be a real safety concern in a high-traffic area.
What causes it
Three common sources
Moisture
Moisture that gets underneath tile, whether from humidity, a slow leak, or a spill that found its way through a grout line, can cause the tile or substrate to swell, which is a common trigger for tenting.
Subfloor movement
Temperature swings, natural settling, and foundational shifts all cause subfloors to move slightly over time, especially in wood-framed construction where the substrate flexes more than concrete does.
Installation gaps
Tile installed without proper expansion joints has nowhere for normal seasonal movement to go, so pressure builds up at the seams instead of being absorbed. This is one of the most common root causes behind both tenting and lippage.
Urgent vs. can wait
Tenting should be treated as urgent. A raised, pressure-loaded seam can fail without warning, and walking on it or letting kids and pets near it carries real risk until it's addressed. Lippage is usually less time-sensitive unless the height difference is significant enough to catch a foot or a wheel, in which case it's worth treating with the same urgency.
Boise Tile Repair resources
- Floor Tile Repair for tile that's cracked, loose, or lifting
- Why Tile Cracks in Boise Homes for more on subfloor movement
- Basement Tile & Moisture Problems for moisture-related causes
Questions
Tenting and lippage questions
Can I just push a tented tile back down?
No. Tenting means two tiles are pressing against each other with nowhere for that pressure to go. Pushing on it doesn't relieve the pressure and can cause the tile to crack or shatter unexpectedly.
Does lippage always mean the installation was done wrong?
Not always. Improper installation is a common cause, but moisture and subfloor movement over time can create lippage even on a floor that was installed correctly to begin with.
Next step
Seeing a raised tile or ridge?
Send the basics now: location, photos if helpful, and how it's changed recently. The more specific the request, the easier it is for a local pro to help.