New Travertine Tile Floor Is Cracking! [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


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john hensler
01-18-2003, 09:10 AM
Dear "John Bridge" Tile Installation Experts:

We have a serious dilemma on our hands and need the opinion of "Tile Installation Experts" as to how we might remedy "Travertine Tile Cracking" (3) months after installation. Here's the history of the job:

We had 500 square feet of "Travertine Tile" installed in the entryway thru to the kitchen area of our "new" home back in May of 2002. The "1960-built" house is very well constructed:
(*) Floor joists 1.5" thick (by) 11" wide (on) 16" centers

(*) We have 3/4" of plywood with approximately 1/16" of the original sheet-type vinyl flooring still in place

(*) The Installer then "nail-gunned" 1/4" backer board on top of the original vinyl

(*) The 18" square Travertine Tiles were then laid diagonally in a "thin-set" bonding mortar

About 2-3 months after it was finished, cracks appeared, 2 (to) 3 tiles in a row and in line with each other. There were five crack areas. Recently, the installer pulled up about 10 cracked tiles, which revealed the backer board. Sure enough, the cracks were in line with the seams of the backer board. More cracks are appearing and they too are along the seam lines of the backer board.

He seemed to believe that the problem is a result of "deflection" or movement of the original flooring. He followed the manufacture's recommendations for installing the backerboard (using appx. 1 1/2" nails placed along markings appx. every 8-10 inches).

I tend to believe that had the backer board been better fastened to the original floor, that perhaps this wouldn't have happened. I also wonder if the vinyl floor had been removed, perhaps there wouldn't have been movement/deflection along the seams of the backer board.

Here are our questions:

1. Why did this happen?

2. What would professional installers suggest we do to cure the problems?

We would appreciate any guidance/help in this matter. Thanks sincerely. Joy and John

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01-18-2003, 09:20 AM
Hi Joy and John, sorry to hear about your floor problems. Let's see if we can help.

You've hit on 2 of the three things I see:

1) The vinyl was left in place. You don't do that for ceramic tile, you really don't do that for stone.

2) The nails should be ring-shanked hot dipped galvanized. I'm not sure that you get them in a "gunnable" form. (I could be wrong)

3) Your subfloor should be "double wood" for stone. Another 1/2" layer of exterior plywood would have been required.

A fourth thing, you didn't mention if the backer board was bedded in thinset. It should be, but I guessing that since the installer gunned in the nails, he didn't know to do that.

01-18-2003, 11:27 AM
Hello John

Can you feel any bounce in the floor if you are standing still & someone runs by, or jumps up & down a bit? If so, your problem is likely to continue to get worse.

I have read some of the pros here talking about joist spans in addition to joist spacing. I believe there is even an engineer who hangs out here sometimes. Not being an engineer myself, I won't even try to advice on this.


Rob Z
01-18-2003, 11:34 AM
Hi John

In addition to the good points already listed....

Did the tile installer finish the seams of the backer board as per mfr instructions?

What thinset did he use, and what does the coverage of thinset look like under the tiles that are removed?

Stone tiles can require half the subfloor deflection (L/720) of the standard number listed for ceramic installations (L/360).

Pictures of the back side of broken tiles that are removed could tell us a lot.

What is the perimeter of the installation? Are the tiles grouted solid to the wall/trim, or is there a small gap around the perimeter , either caulked or covered with base trim?

There is not much that can be done now, other than beefing up the floor joists from below to help reduce the amount of "bounce" in the subfloor, which in turn reduces the stresses placed on the tiles.

01-18-2003, 01:50 PM
Thanks, Dave. I forgot about joist deflection when I saw that they were 2x12s. They have to be longer than 13 or 14 feet to bust the L/720 rule. And even that would not be a tile killer. The real deflection problem comes from the subfloor between the joists, not in the joists. This is stone on a single layer of 3/4" plywood. Not enough. Add the vinyl and questionable nailing method, and you've got the receipe for failure.

This floor could be saved if there were room to install a lot of solid blocking between the joists, like every 16 inches!

01-18-2003, 02:01 PM

What does l/720 and l/360 refer to?
Do you have a link handy that has an explanation in layman terms?


01-18-2003, 03:02 PM
Do a search. Type in Deflection and under user type in bbcamp.
You will get a lot of information on this subject.

Sonnie Layne
01-18-2003, 03:40 PM
John, welcome to the forum(s).

We don't always have good news, but we always come up with good advice. Seems that in your situation you need to arm yourself with qualified information, then approach your contractor and ask him/her why it is that the accepted materials/application methods/substrate requirements weren't followed.

01-18-2003, 04:21 PM
Yeah, what Sonnie said!

01-18-2003, 07:09 PM
If the travertine is cracking along the seams of the backer board I would say that is the basis of your problem. Checking for deflection and perimeter joints is important to see if that might be enhancing the problem but the problem is still the backerboard installation. At this point I cant see much of a cure other then Removing and replacing the whole floor. If your deflection doesnt meet the proper standards for stone I would look into a porcelin replacement.


John Bridge
01-18-2003, 10:51 PM
Hi John and Joy,

I'm afraid I committed a rather embarrassing faux pas. I had a similar email from another couple on precisely the same issue, and I got the two confused. There is another thread in another forum on this site in which I addressed the folks as John and Joy. I tend to think they are long gone, having decided that I'm nuts. :D

In any case, I've read all through this thread, and in the end I have to lean toward Cisco's assessment. It's significant that the cracks occur right where the backer boards join. If the problem were only deflection (and it still could well be), the cracks would occur over the joists, probably.

In any case, and unless you can somehow shore up the floor from underneath, the cure is to tear out the installation and either do it right or not do it at all. As Bob (bbcamp) mentioned, the floor might be up to a ceramic tile installation even though it won't support a stone installation. Travertine is among the softest and most fragile stones we deal with.

And there are the other concerns: the backer board having not been installed over a thin set bed; and the linoleum, which we don't know anything about . . . more wood for a stone tile install . . . problems.

But like all the rest, this is only my opinion. :)

Bill Vincent
01-18-2003, 11:45 PM
The subfloor isn't even up to a ceramic installation-- If it's over plywood, atleast 1 1/4" of plywood in two layers is required, and backerboard is not a substitute. It gives you absolutely no structural strength as plywood does. In the case of travertine or any other soft natural stone, I'd stick with my normal recommendation as a requirement and that is no less than 1 1/2" in two layers.

01-19-2003, 06:19 AM
John, don't be so modest. Since you have written a very successful book on tile setting, I think you are fully qualified to claim to be an expert on the subject who gives expert opinions.:D ;) :p

John Bridge
01-19-2003, 04:41 PM
I'm startin' to think Okies is pretty smart people. :D

01-19-2003, 05:03 PM
I'd be curious to discover what type of backerboard was used too.Possibly hardibacker?

01-19-2003, 05:18 PM
I'm curious if mr hensler will come back to check out the answers..I answered this question 3 days ago in another forum and he hasn't been back there either.:confused:

01-20-2003, 05:39 AM
Originally posted by Bri
I'm curious if mr hensler will come back to check out the answers..I answered this question 3 days ago in another forum and he hasn't been back there either.:confused:


I'm inclined believe John is reading & soaking up as much info as possible.
I also corresponded with him, both on another forum & privately. He has a bad situation on his hands, & I am guessing he may be feeling a bit unsure about what to do next at this point.

John? Have you had a chance to talk to the installer?


john hensler
01-20-2003, 07:50 AM
Bri, Stoneguy, John Bridge and all you good folks who took the time to reply:

Many, many thanks to all of you for your incredible interest and willingness to help us. We've read all the posts and are gathering information with the intentions of posting a summary of what we've learned and answering all your questions.

We regret (big time!) not doing our home work on this phase of the project back when we started last Februaryof 2002. That's when we bought this house (originally built and lived-in by a nationaly known builder "Ed Ryan" of Ryan Homes fame). We finally moved in, in October, after a massive renovation, including Kitchen, 27-Windows, Door's, etc. We did everything ourselves, with the exception of the floors, which were subbed-out.

I do believe that the entire floor must be replaced....but not durring the winter (it's presently 10 degrees here in the 'Burgh) and have somewhat of a plan how to handle it with the installer.

We'll probably post our response later today.

Thanks again.............John & Joy

:bang: :bow:

01-20-2003, 07:53 AM
I would like to hear some of your thoughts on this. Michael Byrne recommends taping BOTH sides of the backerboard on floor installations. He stated that, when a failure occurs over CBU, the failure is most of the time located over the seams in the CBU.

I realize he is known for taking some things to the extreme, but this seems like a good idea to me. What do you think?

01-20-2003, 03:23 PM
Surely someone has a thought on this.:)

john hensler
01-20-2003, 05:21 PM
Dear Experts:

We’re back!

We’ve gathered answers to questions presented in the forum. First, we need to correct a dimension that was given in our first posting:

1. The original plywood floor has a total thickness of 1” with appx. 1/16” or 1/8th” vinyl sheet (not tiles).

Here are further dimensions that might help clarify and determine the probability of future success with replacement.

You should know that this installation was in a main hallway that is supported by 2x12’s on 16” centers with 15’ spans supported on I-beams (junior beam construction without cement flooring). The length of the hallway is appx. 34’ long x 6’ wide. It t-bones at one end with another hallway that leads to the kitchen/dining room etc. That hall is 17’ long x 5’ wide and runs into the kitchen. The kitchen (also travertine tiled) measures 8’ x 10’ with a pantry 5’x 4’. There is a bathroom (4’x5’) and closet (3’x4’) off of the main hall near the t-bone.

The tile weighs 12 pounds and is 18”x18”x1/2”.

Here are answers to questions asked:

1. The backerboard is Hardibacker and is ¼” thick.
2. The adhesive is mortar (we think Flexbond from Home Depot, either in a blue and white bag or a blue, red, and yellow bag).
3. The tile came off in little chunks leaving mortar on both the backer board and the tile.
4. The seams of the Hardibacker were not finished or taped.
5. There was no thin set between the vinyl and the Hardibacker, just the nails.
6. We cannot install solid blocking between the joists every 16” because the heating ductwork, electric, etc occupy those spaces horizontally.

We have some questions:

1. We looked up deflection and found a complicated formula. What is L360 vs. L470 vs. L720? And what does it mean? (in layman’s terms if possible). Given the dimensional information and specifications of the tile, can someone tell us what type of tile should be used in this application if the proper sub floor is provided. (natural stone vs. ceramic tile; large tiles vs. small tiles; diagonally vs. horizontally laid, etc.)
2. If this floor has more wood (subflooring, 1” vs 11/2”), will it eliminate bounce? Does bounce = deflection? We have been asked if we feel bounce when someone runs by, we hear them, but don’t shake up and down as they pass.
3. What is CBU?
4. What is isolation membrane, pro red by c-cure? When they took up the 10 tiles and saw what was happening, the installer tried to cure the problem by laying down a thin “crack isolation membrane” and troweling this pink goo (that turned red when dried) and then laid mortar and the tiles down. That was done this past Friday.

We thank you sooooo much for your time and expertise. We feel that our learning curve has been vertical and your help is greatly appreciated. Joy and John
:bow: :bang:

01-20-2003, 05:39 PM
Im not an expert, but it is my opinion that the failure is 100% the installers fault. Your floor as is is not suitable for natural stone. Even if it were, the guy that set the tile did everything wrong from start to finish. I hope he gets to come back and re-do everything out of HIS pocket!

Bill Vincent
01-20-2003, 06:35 PM
John-- I've got a couple of things to say about your floor. First of all, it makes a difference (however slight) whether the vinyl is 1/16" or 1/8". If it's 1/16", then it's just normal linoleum, and although it's recommended NOT to leave it in under a tile or stone install, it IS acceptable. However, if it's 1/8", then it's cushioned, or padded vinyl, in which case it'll crack your tile every time, no matter HOW you try to compensate for it. Now, your plywood NEEDS to be thickerer, even with CBU over the top of it. That plywood MINIMUM has to be 1 1/4", and I'd recommend that it be atleast 1 1/2", and THEN put your cement board down over it. The cement board adds no structural value and therefore can not be substituted for part of the necessary plywood dimention. Once you get rid of the vinyl and add the required plywood, I think you'll find out that you've gotten rid of any bounce that you're feeling in the floor.

As for the thinset, it sounds like the proper thinset was used, because of the fact that neither the back of the tile, nor the underlayment came out clean. If it was the wrong stuff, one or the other side would be almost clean.

Also, the fact that the seams weren't taped leads me to believe that your installer wasn't too concerned with the quality of his installation, as opposed to this being an honest mistake.

AS for feeling bounce, especially in the case of a soft stone like travertine (and even more so with the 18x18), if you feel a vibration in the floor as someone's walking on it, that's too much bounce. Again, I think once you use the recommendations I've given you, it should take that out.

CBU is the cement board (in this case the hardibackerboard) used on your floor.

As for a crack isolation membrane, your installer might be headed in the right direction. However, I'd try building the floor to specs first, and then if there's still a problem with vibration in the floor, I'd think about putting down a layer of Ditra.

01-20-2003, 07:08 PM
No tape-No thin set under board-cracks above seams-- bingo ! Red Guard from Custom is not made to prodect individual tiles as you contractor has installed it.--

01-20-2003, 07:19 PM
Ill ask this one again. Does anyone besides Michael Byrne tape BOTH sides of the CBU?

01-20-2003, 07:19 PM
Here's the hardiboard installation instructions...from reading it, they did more than one thing wrong.:(

1 Ensure subfloor is structurally sound:

On existing structures:

HARDIBACKER ® sheets may be installed over Vinyl Composition Tile (VCT). However, remove all other existing floor coverings including cushioned vinyl.

Ensure the sub-floor is not damaged. Replace any loose, warped or damaged boards.

Make certain subfloor is a clean and flat surface.

For all floors:

Use minimum 5/8" exterior grade plywood or 3/4" exterior grade OSB, complying with Local Building Codes and ANSI A108.11, over joists. Joists' spacing not to exceed a maximum of 16" on center.

Deflection must not exceed L/360 of the span, including live and dead design loads.

Do not use glue between grooves of tongue-and-groove plywood to allow for expansion and contraction of plywood.

2 Determine layout of HARDIBACKER ® sheets and Score & Snap

Stagger all HARDIBACKER ® sheet joints. Do not align with plywood joints.

Never allow all four corners of sheets to meet at one point.

Keep edge of sheets 1/8" back from walls and cabinet bases.

3 Attach HARDIBACKER ® sheets to subfloor

Apply a minimum of 3/32" thick dry-set mortar or modified thinset to subfloor.

Embed HARDIBACKER ® sheets firmly and evenly in the wet mortar. Leave 1/8" gap between sheet edges.

Using the printed dots as a guide, fasten HARDIBACKER ® sheets with proper nails or screws (as listed in "Materials Required") every 8" over the entire surface. Keep the fasteners between 3/8" and 3/4" from sheet edges and 2" in from sheet corners.

Set fastener heads flush with the surface without overdriving.

4 Expansion Joints must be provided in the following situations:

Over existing structural joints.

Where the floor changes in direction, such as in "L" shaped rooms.

In the center of the floor where room exceeds 15' in any direction.

Where changes occur in backing materials.

01-20-2003, 07:29 PM
The logic is there for taping both sides I have had this conversation with M Byrne. But to answer your ques.I have never talked to anyone else doing this unless they were following written directions for installing S.R.-Board (KINETICS SOUND BOARD) and even then they only did it if someone was watching the install.

John Bridge
01-20-2003, 09:19 PM

The minimum standard for stone tile deflection is L/720 (which is twice the requirement for ceramic tile). It means that in in span of a joist, for instance, it can't depress more than 1/720 of its overall length (span) when subjected to a 300 lb. concentrated load. In a span of 15 feet this comes to a quarter inch. Remember, that's a minimum requirement and in my opinion it's excessive. I think a quarter inch is a lot for large stone tiles, but that's what the book says.

Where the thickness of the plywood really becomes important is BETWEEN the joists, because the L/720 applies there as well.

Bounce can be compared to what we call the "trampoline effect," wherein the floor actually reverberates when someone jumps on it or runs across it. I advise what I call the "jump test" as an indicator (and only an indicator) of a floors suitability. Now, I've gotta tell ya, the "jump test" is not sanctioned by the tile industry. ;) But anyway, if a floor has a lot of bounce to it, it often follows that is has excessive deflection as well, and as has been stated, it's the deflection that'll kill you.

But there are so many things wrong with your installation (as Bri pointed out) that we shouldn't only worry about one element.

scott anthony
01-21-2003, 02:33 PM
Hey John
First I must tell you I am by no means a so called pro. But I can tell you one experience, and it's with my own house.
It seems to me your installer is at some fault if what you state is accurate. At the same time I know an installer who seldom uses thin set under the hardi board. I don't associate my work with his and I question him all the time on it. He says he has never had a failure related to that method. Personally I don't believe him. And I think that method would be unheard of. ANYWAY.
If you decide your stripping off the old floor and replacing it with tile again, check one thing out.
Check your geotechnical conditions. If you live on or with a clay soil condition your piers will move according to the rainfall. Clay expands when wet and shrinks when dry. I live on clay and have tile in half of my house. I won't get into what I did keep from tile failures now.
I am just saying this problem you are facing my be the result of a combination of issues, as to where now it seems like an installation witch hunt.

I don't know this installer and don't care too, that's not my point here.
And just to refresh all the pro's, I would never delete thin set from my backer installation.

john hensler
01-22-2003, 09:53 AM
Dear Experts:

We’re back, again!

Thanks to all of you good folks for the vast amount of information that you’ve shared. We feel that we’ve got a pretty good handle on why our floor cracked and what our options are to resolve this matter. There are (2) questions we have.

1. A couple of the posts suggested that the responsibility for our floors failure lies on someone besides the “installer”, in this case. Are we to believe that we, as consumers, should have done the calculations ourselves to determine the materials and methods required? I thought “knowledge” and the ability to apply it was the very value that separates a “consumer” from a “specialist”. Heck, if that’s the case, why do we have schools that educate people to perform specialized work? (Doctors; Electronic Tech’s; Tile Installers; etc.) Well, we disagree. We hired the installer based on a referral from the tile supplier’s salesman because he was familiar with his work. We know some of you folks agree with us and some disagree. Would you please give us you opinions, one way or the other?

2. Based on all of the information that we’ve provided you, do you believe that, if we remove all of the materials installed,
remove the old vinyl, add a ½” of plywood to existing 1” of plywood, add a backer board installed with thin-set and the appropriate fasteners, that Travertine ½” x 18” x 18” laid diagonally will not fail?

We would like to hear what you folks think.

Joy and John

:bang: :bow:

01-22-2003, 10:46 AM
per the ansi. standards-
Prior to commencing ceramic tile work, the contractor shall inspect surfaces to receive tile and accessories ,and shall notify the arch.,g.c. or other designated authority in writing of any visually obvious defects or conditions that will prevent a satisfactory tile installation. Installation work shall not proceed until satisfactory conditions are provided.

now the question is what is obvious-

01-22-2003, 10:51 AM
Your installer should have been knowlegable in all the areas we have been discussing. Trouble is, some aren't. Approved installation procedures are available. Heck, for as little as $10, anyone can have a set on hand for reference, so cost is no excuse. The home owner should not have to educate himself in all of these requirements, but must often have to to protect himself from those installers who don't bother with education.

Looking back at your thread, I read that the floor joists are 2x12s on 16" centers, 15 feet long. The joists are not up to a natural stone installation. You will have to either support the joists at mid-span with a beam and piers, or double each joist with another 2x12. I apologize for not catching this sooner.

The rest of your plan sounds fine, though.

01-22-2003, 10:51 AM
Originally posted by Jeremy
Ill ask this one again. Does anyone besides Michael Byrne tape BOTH sides of the CBU?

no. I tape the top..

Sonnie Layne
01-22-2003, 02:58 PM
Jeremy, oh, sure I tape both sides...

y'see I lay out the cbu the size of the room, then take it outside, turn it upside down and tape the back,... got it?

Then I cut out the door, ceilings and roof and haul the whole thing back in, lay it down (careful to note that the right side is up) and tape the other side.:laugh2:

I think I'm gonna right my own buuck.

scott anthony
01-22-2003, 03:27 PM
Hey John
I am by no means blaming anybody for your situation, but I will repeat myself. If you are on CLAY soils I don't care what under structure you have, clay will take over. I spent $40,000.00 just on the perimeter of my house. Please do a simple check of your soil, unless you already know.
I hope things work out for you in the end.
That will be my last post on clay. If you've only seen what Iv been through you would understand my concern to help and that's all it is.
And nobody cares who tapes both sides of backer board. If you feel you need to, go for it.

01-24-2003, 09:37 PM
Sonnie, surely you can figure out how to tape the back-side of the CBU without removing it from the jobsite.?! :p