Tile Floor Tenting/Buckling [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


View Full Version : Tile Floor Tenting/Buckling

01-05-2007, 12:33 AM
Great Forum!!

I went away for vacation over the holidays and came back to about 4 tiles by 7 tiles in a raised/buckled state in my kitchen. After reading this forum I believe I have the unfortuate assesment but wanted to run it passed the pro's.

House was built by previous owner in 1999 so I have no history on the tile or workmanship.

Before I pulled up the tiles as shown the tiles would sound hollow underneath (I have other tiles in the approx 600 square feet of tile in the joining kitchen and breakfast nook that sound hollow when knocked on but are not tenting)

I had 1 tile person tell me it could be from moisure from the slab (this was said without looking under the tile). I bought a moisture kit to try but thought I would get feedback here first.

When I bought the house (used) the grout was really dirty so I cleaned it with acid and sealed it. It already looks dirty again after 2 years in spots so I am wondering if it could be moisture along with other things? As you can see the tile looks like it is darkened like maybe it came up from moisture? It has been raining and cold (30's) in dallas over the holidays and I had my heat turned down to about 45 degrees. When we got home it was 52 in the house.

1. It looks like they grouted all the way to the wall. I cant tell 100% because there is 1/4 round then base board. Under the 1/4 route it is all tile to and under the base board which I dont want to pull off of the wall (picture attached). The island in the kitched has the tile going right to it with no grout or putty, around the door entry it has calk, up against the kitchen cabinets it is grouted to the cabinet for sure.

2. I put water on the concreate and the water does not seep into the concrete (picture attached).

3. The mortar did not stick at all to the concreate when pulled up and stayed on the tile (picture attached).

Issues I face... The tenting is in the middle of the kitchen. I am thinking about pulling up the loose tiles and putting them back down as I dont want to replace over 600 sq ft of tile right now.. Other issue is that I cant find the same tile if I break any and have only 1 spare.. :(

Sponsored Links

Dave Gobis
01-05-2007, 05:46 AM
That the water does not go into the slab is part of the problem. The cement (thinset bonding material) was not able to bond to the slab and is just resting on the top. The moisture in the slab will cause the growth in the tile. Once that happens as there is little to no bond the floor arches up from the pressure exerted by being pegged into the wall tightly with grout. You can patch it but the problem is not over, more than likely it will be a continuing problem unfortunately.

01-05-2007, 08:18 AM
Dave, for a temporary measure, what about installing a soft joint or 2 in the area of the repair?

Swimmer Steve
01-05-2007, 09:11 AM
Us lurkers gotta know. :uhh: Is the moisture coming from condensation on top of the slab or is it caused by moisture getting through the grout or something else? Apparently the slab was sealed so could moisture still come up through the bottom? Thanks,

Dave Gobis
01-05-2007, 09:13 AM
It would help but once the pressure has been relieved on the floor the rest usually comes loose sooner or later. If the floor is remotely bonded it all it would push it into the later time frame. That is the typical history.

Dave Gobis
01-05-2007, 09:25 AM
Texas is notorious for subsurface moisture issues with slabs. All concrete slabs breathe moisture. The relative humidity of soil is 100%. Curing compound slows it down (so the concrete can hydrate) but does not stop it. With heavy rain, the rate increases. Tile has a permanent non-reversable growth rate due to moisture expansion, that is one reason why we are always preaching movement joints.

John Bridge
01-05-2007, 09:30 AM
Hi all, :)

I used to argue with Dave about this, but I don't anymore. I've seen my share. :)

As a short term repair you can re-install the tiles and leave the soft joint mentioned around the repaired area. Additionally, you can saw out some other grout joints and create soft joints between other areas. Essentially, this makes small tile installations out of a large one. Small areas don't expand and contract as much as large ones overall.

Moisture in the slab can affect the way it expands and contracts, but moisture is seldom a problem in the tile layer as it usually evaporates through the grout (and sometimes the tiles).

I think the cause is exactly as Dave has stated it. :)

don metzinger
01-05-2007, 10:24 AM
Dave, would you explain a bit more about what you mean in your reply above, "growth in tile" thanks - Don

Dave Gobis
01-05-2007, 11:01 AM
Well, little deep for the shallow end but as long as you asked............There are 2 causes of tile growth, thermal expansion/contraction and moisture expansion. Any source of heat will cause the thermal and it is an ongoing cycling. A tile will never contact to less than it's original size. Moisture expansion is a little more long term and one way, always expansion. There are tests to make sure they both fall within a given set of parameters.

ASTM C370-Moisture Expansion. This test measures the amount of expansion in a tile with water introduced into the tile body.

ASTM C372-Thermal Expansion. Measures the amount of linear expansion in a test specimen with heat.

This is why the type and amount of thinset applied to the tile as well as accomodating any anticipated movement are important in every installation. Given the various settings in which tile can be installed, each installation has it's own unique considerations. Lot's of windows mean a better thinset should be used than a closet type installation. Not that a lessor product wouldn't work, it just comes with increased risk.

01-05-2007, 01:44 PM
I dont think the problem has anything to do with moisture.

I think the problem is the contractor covered control joints and now the floor has nowhere to go but up. When a floor buckles the thinset can shear clean from the concrete. That doesn't necessarilly mean the floor wasn't bonded. The new thinsets with latex will just about stick to anything. They stick to glass and porcelain that don't absorb water so a few ounces of water puddling on your floor doesn't mean the floor wasn't bonded.

01-05-2007, 01:46 PM

Does the amount of moisture a tile absorbs relative to the type of tile? ie. ceramic vs porcelain. How about size and thickness? I would also assume that natural stone is more susceptible to moisture? Is this correct?

Thanks .........

01-05-2007, 01:55 PM
Thanks for all of your replies..

1. Do you think I should even do the moisture test ( I bought one made by taylor tools that takes 24 hours and then you use a gram scale to determine moisture calc)?

2. What is the soft barrier material called so I can get it?

3. Would I do like 3/4 fill of the barrier material and 1/4 fil lof the grout on top of it so it looks good?

4. Should I sand or put anything down as a barrier in the section of flooring I am repairing (if so what) ?

5. Is there a easy or gentle way to get the thin set off of the tile so I can re-use the tile means I dont have any spares (I am using a 4 inch hand grinder to remove the grout).

Thanks again for your kind time...

Scottish Tile and Stone
01-05-2007, 02:13 PM
1. I wouldnt bother with the test.

2. Use matching caulk for the soft barrier.

3. No use only caulk.

4. Just use a premium latex modified thinset

5. Use your grinder with a diamond blade. It will come off pretty easy but
very dust.

Dave Gobis
01-05-2007, 07:59 PM
Max, I stand by my opinion and am glad to back it up anytime. You want to hash it out, we can go to the deep end, just give me a ping.

I agree with Scotty except The curing compound needs to get roughed up if anything is going to stick to that slab unless my eyes deceive me.

Red Rock, tile has a rating system.
Impervious tile with water absorption of less than 0.5%.
Vitreous tile water absorption of more than 0.5%, but not more than 3.0%.
Semi-vitreous: Tile with water absorption of more than 3.0%, but not more than 7.0%.
Non-vitreous over 7%. Wall tile has water absorption of 7.0 to 20.0%.
Porcelain tile by sole definition has an absorbtion of less than .5%

Tile is unaffected by water and inert, however, it does have a growth rate. Thicker would not affect the rating, it is a percentage of weight gain. Lastly, tile can actually be bonded under water, not just submerged, with the appropriate setting products.

Scottish Tile and Stone
01-06-2007, 07:40 AM
Dave, is that pre-mix?

Dave Gobis
01-06-2007, 08:50 AM
No it is a small sack inside. I can find another picture in a 25# bag if you like, Ardex makes one too, LOL. We used it on swimming pool repairs. Comes white or gray.

01-06-2007, 04:00 PM
Is there any other way to get thinset off of the tiles besides hand chisel and using a diamond cut blade that was recommended (not feeling confident about using the blade to get it off)? I took 25 tiles up this morning and all of the thinset (100%) stuck to the tiles.

Thanks Again...

01-06-2007, 06:33 PM
It will take some time but grinding the thinset off with a grinder and diamond blade is the fastest way I know of. On a table outside, lay the tile on a towel or something soft to keep from scratching the face. It will be dusty, might want to use a mask. :)

Scottish Tile and Stone
01-06-2007, 08:18 PM
LOL Dave, you remembered the ardex post.. Hahaha

Dave Gobis
01-06-2007, 09:22 PM
No, I didn't. What was it?

Scottish Tile and Stone
01-06-2007, 10:47 PM
Ah schucks nevermind..