Expert Answers
Is it Ok to Install Tile Over Tile
QUESTION
I am seeking a professional opinion on the method of tiling installation that was used by a recent contractor I hired.I recently employed a contractor to demolish existing tile and heated flooring and reinstall a heating mat and new tiling. The contractor completed this work and discovered afterwards that the mat he installed did not work. He offered to install a second time, but unbeknownst to me (I was out of town for the second install), he did not demolish his first installation. He instead laid leveler and installed a second heating mat and set of tiles on top.
I am not happy with the quality of the second installation, but he insists it is the same as the first. I am wondering if this “layering” installation method is an accepted industry practice. He did not consult me before deciding to layer instead of demolish.
I understand that if I were to use your opinion in arbitration or a court, I would need to retain you at a fee. For now I am simply seeking an opinion so I can weigh my options.
Regards,
Melissa
ANSWER
ANSWER - Per the tile industry standards it is acceptable to install new tile over an existing tile installation. Of course the new installation is only as good as the underlying installation. If the only problem of the underlying installation is that the floor warming system doesn't work then there should be no problem with installing the tile over it. Of course that is assuming that the first and second tile installation was done properly. Sometimes you don't have the room to install tile over tile because of the height of the existing conditions such as door thresholds.4 thoughts on “Is it Ok to Install Tile Over Tile”
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I want to add a small 2″ x 2″ tile on top of my saltillo riser of stairs outdoors. And I will only put the small tile on every other saltillo tile – not straight across. Can I use an adhesive and simply put it on top of the existing tile? It will obviously stick out a little but it won’t be on the walking surface. And would it look better with a glass liner around each side? Thanks for your advice.
It is possible to install a tile over an existing Saltillo tile if you use the right thinset mortar adhesive and properly prepare the surface of the Saltillo tile. It might look a little odd…
You would have to scarify the surface of the Saltillo tile and clean it so it is stable and clean. Not all Saltillo tiles are hard. Some can be soft because of the low firing range in the kiln. You should use a modified thinset mortar for bonding the tiles together. Of course the installation will only be as good as the Saltillo itself in terms of how well it is bonded to the stair riser substrate.
I am unraveing a series of installation concerns in a current master bath remodel.
The contractor has recommended tiling over his installer’s work, saying that removing the shower wall tile and grout and the limestone shower floor, curb and bench will compromise the shower and waterproofing. Is this accurate?
– Is tiling over a usual practice? Are there reasons not to tile over? Is it a short cut that creates problems? Are there materials that should not be tiled over?
– Theexisting shower wall is fireclay tile. The shower floor is a brush hammered limestone. The shower bench is a honed limestone. I trusted our pros but am now having to double check on the basics. None of these materials seem to have been properly prepared nor installed – none have been sealed. All seem to be quite porous. The dark grout used has stained the white crackling in the tile and filled in areas of the limestone. It’s a mess.
Below are the specs for the limestone material used. Should they have even been used in a shower?
Moh’s Hardness: ASTM C1895 (honed -3) (brush hammered – 4)
DCOF ANSI A326.3
Breaking Strength ASTM C648 – 1649 lb. average
Absorption ASTM C373 -2.4% nitrous
Is this limestone appropriate for shower floor, shower benches and installation over heated floors elements?
What is the industry standard for waterproofing and substring prior to tiling?
Thank you,
Tiling over tile is an acceptable installation method per tile and stone industry standards. Although the new tile will only be as good of an installation as the underlying existing tile. If the existing tile is structurally sound and the new tile is properly installed over it including having adequate waterproofing then it can be considered an acceptable installation.
It is not unusual to install various types of ceramic tile and limestone in showers. They have to be installed correctly to perform correctly. They have to have adequate slopes on the horizonal surfaces with adequate drainage.
You can review the ASTM C568 standard for natural limestone. It is broken down into 3 categories of Low Density Limestone, Medium Density Limestone and High Density Limestone. The minimum and maximum physical properties are listed for each category and they vary respectively.