How do you repair hollow sounding tiles?

QUESTION

How do your repair hollow floor tiles and hollow wall tiles?

ANSWER

ANSWER - Hollow sounding tiles is not a defect per se.  Depending on the substrate and installation materials and methods being used the tile can have a hollow sound without anything being wrong.

On the other hand, when some tiles or portions of tiles sound hollow and others don't that might be an indication that there are excessive voids under the tile or that the tile or some component in the tile assembly isn't bonded.

Spot bonding tiles is where 4 or 5 spots on the back of the tile are bonded to its substrate rather than the entire tile surface being bonded.  This is not considered a legitimate method of installing tile unless it is with an epoxy adhesive on a wall.  This means that if only 50% of the tile is bonded then the potential bond strength of the tile has been diminished by 50%.  Now 50% might still achieve a substantial attachment under ideal conditions, but it doesn't meet the standards and makes it more susceptible to potential problems.   It also means that those unsupported areas of the tile will have a greater propensity to damage than where it is supported, and that for exterior applications or in interior wet areas moisture can collect in those voids causing staining problems.

There is no way to repair the hollow tiles so they are not hollow any longer other than replace them.  Over the years many have tried to inject epoxy through the grout joints to reach under the tile, but I have never seen it work.

6 thoughts on “How do you repair hollow sounding tiles?

  1. Denise Bucklad says:

    I was reading an article you wrote about Hollow sounding tile, from July 2013, Leslie Goddin. I am hoping that you can help me, give me guidance, or point me in the right direction.

    We are the second owners of our home. Had we been the ones building it, this would not have gotten passed me. Unfortunately several of the tiles in the lanai and a few in the house sound hollow. The floor is travertine inside and out. It appears that the tile layer only put thinset in the center of the tile. Thus causing the corners of the tile to crack.

    I would like to fix it, without having the remove the entire floor. I can’t imagine the cost because it is approximately 5,000 sq ft.

    I am wondering if there is a product that can be injected into the grout line (once removed) to file the voided areas? I think there would have to be multiple areas for injection. The broken tiles would be removed, giving me a greater chance to fill the voided areas. I know that concrete is leveled by pumping a cement and limestone mixture (very thin viscosity) between the dirt and the cement to fill the void and raise the cement.

    Also is there some type of membrane or tape that can be placed over the joining of two cement slabs. They just laid the tile directly over it, and either the grout is now cracked or the tile is. Have you ever done any repair like this? Am I on the right track? What do you recommend?

    I am attaching several pictures of the issues. The last picture is of the step. The gap is in front of the step. It is like the step foundation wasn’t as wide as the tile going on top of it, and they didn’t fill in the gap, but just laid the edges of the tile on top of each other. I have more pictures, but I couldn’t attach them all.

    • Donato Pompo says:

      Spot bonding stones or tiles is against the industry standards. If the corners and edges of the stone is not fully supported by the thin-set mortar adhesive then it will have a propensity to crack or crush. That is why the industry standards for natural stone requires 95% contact with full support under corners and edges of the stone, and no voids larger than 2 sq. inches (size of a golf ball).

      Although it isn’t an industry endorsed repair method some people have used a product called Fix-a-Floor (https://fixafloorworldwide.com/) that is a latex-like liquid that is flow-able and can be fill voids under tiles through drilling holes into grout joints. I have seen this product work in one case and I have seen other cases where it didn’t fill all the voids. Just depends on the depth and how large the voids are and whether there is a sloped surface underneath the stone. There is no guarantee that it will work adequately. Otherwise you should remove the stones and replace them with others.

      Regarding transition joint known as a cold joint or a control joint in the concrete between two separate pours, you should never bridge those joints. Per industry standards that joint should continue up through the stone. The joint should be filled with a foam back strip and caulked with an ASTM C920 traffic grade polyurethane or silicone sealant.

  2. Jazzy says:

    I have more than 30 tiles that are hollow;

    foyer 11 hollow tiles

    entrance to kitchen 15 hollow tiles 1 cracked tile

    master bathroom 12 hollow tiles 1 cracked tile

    guest bathroom 8 hollow tiles 1 cracked tile

    The contractor does not want to repair these tiles.

    Your thoughts?

    • Donato Pompo says:

      Technically a tile being hollow is not in itself considered to be a defect per industry standards. There are conditions where tiles will sound hollow due to the underlying materials being used or the condition of the underlying substrate that will not affect the performance of the tile.

      On the other hand, a hollow sounding tile that is partially hollow sounding could be a symptom of excessive voids under the tile. If there are no resultant damages, such as loose tiles or cracked grout around the hollowing sounding tiles, from the hollow tile, then the tile might be securely attached to the floor substrate.

      Although if there are excessive voids under the tile which is more than 20% of the tile for interior residential applications and if it isn’t dispersed voids or if there are voids along the edges and corners of the tile, then it might give the tile a propensity to crack in those unsupported spots if they are subjected to a heavy and sharp enough load/impact.

      The only way to determine what the hollow sound represents is to remove tiles under various conditions and evaluate those conditions relative to the industry installation standards.

  3. Michele Hulse says:

    Can’t we remove an intact, hollow tile, clean the Bonding material off the substrate , then rebound it? We live in AZ an for some reason many of us have had tiles “pop” this winter. They appear intact and undamaged but now sound hollow. We had this occur to 10 tileS in our hallway 2 nights ago. We now have a total of 35 hollow tiles. A tile service person says he has a “mudd” made for outdoors that is somewhat flexible and he can use this when removing and putting back the old tile.

    • Donato Pompo says:

      In theory, if you remove a loose tile where the adhesive doesn’t adhere to the back of the tile you could re-use it as long as there isn’t some sort of contaminate on the back of the tile. You will have to remove the adhesive on the substrate.

      Normally when tiles tent up or come loose it is because there are not adequate movement joints to mitigate the expansion and contraction of the tile from thermo and moisture movement and it probably wasn’t bonded as well as it should have been to the substrate for one reason or another.

      If you are only replacing tiles then you are treating the symptom of the problem rather than the problem so the symptom of the problem is likely to reoccur.

      Whether the thinset adhesive or the mortar bed is a polymer modified mortar bed with better properties, you are still required to have proper placement of movement joints at all restraining surfaces and every 8 to 12 feet in each direction for exterior applications. The sealant to fill the movement joint should be an ASTM C920 traffic grade sealant, which is normally a polyurethane type of sealant over a foam backer rod.

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