Can porcelain tiles warp after they are installed?


I need assistance with a query on tile tenting. we have a patio floor about 100m2 which is tiled with a 60x60 glazed rectified porcelain. The floor was tiled back in 2012 however the tiles have started to tent recently. there are no expansion joints or perimeter joints on the patio (second floor patio). however the tiles that have tented are bowed/warped on the edges and the tiles that have not tented are true with no warpage. i had two tiles tested that lifted and the water absorption is 0.05% which should rule out irreversible moisture expansion. My question is, can a porcelain tile warp/bow after installation (due to stress)? if so is it possible that if a tile can warp/bow will this cause the floors to lift?


ANSWER -  All tiles have some inherent warpage from the manufacturing process and the ANSI A137.1 is the standard that states what is allowable.

Some natural stones and some quartz stones, and some concrete tiles are known to sometimes warp after the installation under various conditions, although it is not common.

Porcelain tiles are impervious so they don't have enough absorption to cause enough expansion that would result in a porcelain tile to warp.  I have never seen or heard of it happening to a porcelain tile after it is installed.

Tile tenting is normally the result of lack of movement joints (expansion joints) at the perimeters and within the field of tile, along with the tile not being as well bonded as it should.

15 thoughts on “Can porcelain tiles warp after they are installed?

  1. Louis says:

    I can’t imagine porcelain tiles distorting. Breaking (maybe with microcracks) but never distorting. The stuff is very, very hard. It doesn’t bend.

  2. Doug behnke says:

    Thank you for your response. I was recently told to be careful where I purchased the porcelain tile because the tiles will warp or possibly cup. I questioned how a fired porcelain tile could wrp and cup but didn’t get a good answer. Aside from what might happen in the manufacturing process as you mention I don’t understand how this can happen. I have three cartons of various porcelain tiles out in my entry to do some color and style selection. Not one of these are warped or cupped to make any noticeable impact on the tile.if so it semi as though the tile would break. Thank you for your insights on this topic.

  3. Donato Pompo says:

    Porcelain tiles can warp during the manufacturing process. There are standards in terms of how much warpage is allowed relative to whether it is a calibrated or rectified porcelain tile. I don’t think it is possible to have a fired porcelain tile warp after being installed.

    There are quartz resin tiles, some concrete tiles, and various natural stones that can warp after being installed, but that has much to do with what they were installed over, what they were installed with, and how they were installed.

  4. Donato Pompo says:

    Porcelain is not known to warp after it has been manufactured. It is a very dense and impervious material. It does exhibit warping during the manufacturing process and there are maximum allowable tolerances for porcelain tile that varies depending on whether it is a more consistently sized rectified tile or a standard calibrated tile.

  5. Ian Sumallo says:

    Ten pcs of 60×60 cm perfectly flat ceramic tiles installed in our house floor in 2012 started to cup or bend inwards in their middle portion in 2016. Six (6) of them were adjacent to each other in the middle portion of the living room. The rest were scathered rondomly throughout the floor area. There were spaces about 1cm between the floor tiles and all the walls so tiles can have room for movement, yet the cupping of tiles still gradually occurred. When one steps on the edge of the cupped tile, it moves up and down like being in a diving board but it doesnt break in the middle. Now 3 more tiles are showing signs of gradual warping as their opposite edges are turning upwards. Ive search the internet for answers but it seems no one has encountered this particular kind of problem.

    • Mel says:

      The same thing has happened to us recently. The whole tile floor came up at once in the master bedroom and the tiles could not be reinstalled due to cupping/warping. The floor was installed in 2012 and came up this year.
      After re-tiling the whole master bedroom the next month it was the kitchen and living room, same thing. Still a mystery to us what caused the warping.

      • Donato Pompo says:

        I would like to see the data sheet on these tiles so we can determine what they are made of. Porcelain tiles are not known to warp after they are installed. Resin based tiles, or manufactured quartz tiles, are known to warp after they are installed. Also some concrete tiles and natural stones can warp too.

  6. Donato Pompo says:

    I would like to see the data sheet on these tiles so we can determine what they are made of. Porcelain tiles are not known to warp after they are installed. Resin based tiles, or manufactured quartz tiles, are known to warp after they are installed. Also some concrete tiles and natural stones can warp too.

  7. Andy says:

    Just in the progress of renewing porcelain tiles in office entrance after cupping , old tiles where fitted 9 years ago by my self 45 years experience seen nothing like it before

  8. Donato Pompo says:

    It is normal for porcelain tiles to have some warpage from manufacturing and there are tolerance standards for it. I have yet seen a porcelain tile warp after it was installed or after it was manufactured that by definition is impervious and has less than 0.5% absorption. I would have to see it to believe it.

  9. Lee says:

    Want to install porcelain tiles on fenced concrete patio – 6ft x 10.5ft. I was told thinset is required for a strong base. Is that necessary? Is there a less permanent solution? I plan to sell the condo and worry if the new owner wants to replace the tiles with other porcelain tiles? Please advise. Thanks!

    • Donato Pompo says:

      There is no valid way to install a 5/16″ thick porcelain tile over a concrete substrate unless you adhere it with a thin-set mortar. There are sand-set methods, but the porcelain tile has to be at least 3/4″ thick if not thicker. Typically sand-set pavers are 2″ thick or more.

      There are uncoupling membrane systems that you could not adhere to the concrete but adhere to the membrane that would make removing the tile easier, but it they could be susceptible to cracking as it would be an unstable surface.

  10. Linda Hartwell says:

    Hi Donato,

    You are welcome to come see my porcelain tiles. When they were installed the room was like a smooth sheet of glass. Now 50% or more of the tiles are cupped, lifted and cracked. I have engineers, contractors and others in and everyone has a different guess. Some have such a significant bow to can stand on the outer edge and rock on it.

    • Donato Pompo says:

      If the tile floor is in the condition as described above there is much more to this story than the tiles simply warped.

      Warpage in tiles is normally caused by moisture. A true porcelain tile is impervious and can’t absorb more than 1/2 of 1 percent. All tiles are manufactured with warpage and the industry has allowable tolerances for warpage depending on the type of tile and its physical properties.

      Resin based tiles and cementitious based tiles in limited cases are known for warping during or after installation depending on the type of substrate to which it is attached.

      The only way a tile can warp after it is installed is that the tile’s tendency to warp has to exert a force greater than the tensile bond strength of the tile’s attachment to its substrate. Thin-set mortars that are properly used to install tile can achieve over 200 psi tensile bond strength . For a 12×12 inch tile that would require a force greater than 28,000 pounds for it to debond assuming it is properly bonded to a structurally sound substrate.

      If a proper and thorough forensic investigation was performed on the above referenced installation we could determine exactly what has led to this failure. Although sometimes it isn’t practical to spend the money required to perform the forensic investigation. We have been performing tile forensic investigations for over 17 years full time all over North America and beyond, and we have pretty much seen it all. Typically when there is a failure it is due to multiple compounding deficiencies. Initially the problem is often reported as if it is a phenomenon, but once the investigation reveals the facts, it always becomes clear what has caused the failure.

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