D.C.

In 2004 we built a new 10,000 sf slab on grade house and installed 5000 sf of 2'x2'x3/4" limestone over an unnamed slipsheet/afm that was adhered rto the slab with proprietary adhesive. The sub puddle-set the tiles, used no expansion joints in the field or perimter expansion. The installed tiles were wet-honed to a nice finish, sealed, then covered with drywall protection. Then the cabinets were set, walls were painted, etc
Before completing the job, we pulled the protection to find that all of the tiles had started to spall along the edges? 1/8"-3/8" wide flakes of limestone maybe 1/8" thick breaking away pretty consistently along all of the tile edges. A forensic tile expert was called, destructive tests were performed, and they concluded, no expansion combined with slipsheet failure due to improper installation. The sub removed the entire floor and slipsheet. The experts performed dome tests, the structural engineer examined the slab, and pour documents to no avail.

They installed the new slipsheet with manufacturers rep training, and tile expert monitoring, then installed the tile with expansion in the field and perimiter, and more expert monitoring, and honed and sealed the tiles. Because his liability insurance would immediately cancel him, he paid for it out of pocket. We stood next to this honorable sub, and bought all the material.

Well the damn thing spalled again after the client moved in. Needless to say we are now facing our first lawsuit. The "expert" has no insurance and excludes himself from liability from the git-go. The slipsheet manufacturer simply alleges we put it in wrong and shows us his army of attorneys, and he's out. That leaves the builder and the tile sub to screw.

We think the slipsheet manufacturer has a faulty product, and he's hiding the other failures. We have heard of one other local failure with this brand and are trying to dig up some info on it. What I wanna know is, do you guys have any experience with slipsheets causing failures like this, or what do you think caused the failure?
Thanks in advance.

R&D Tile

What is the name of the product used and how was it applied, your talking about a membrane correct?, you don't install tile on a slipsheet, you mud over a slipsheet, then tile.

This slab did cure for a full 28 days prior to having any work done it, correct?

Bud Cline

Occupation: Stupid-tendant?
Handle: Clam Inspector?

And you expect us to take this serious and supply you with straight answers for free when a professional inspection would cost your company thousands?

I can tell you how to have it inspected professionally with results that will hold up in court and an inspector qualified to give expert testimony in court if that's what you want.

I would however be curious to know if the spalling was only around the perimeter of the area or the perimeter of each limestone slab?

D.C.

Bud, a little levity up front is necessary in this line of work. When you read my post did you find any humor? Is it a funny subject?
I dont expect that you guys do anything, I hope you share some of your wisdom on worthy subjects.

The spalling occurred around the perimiter of each limestone slab.
The tile was "puddle-set" on a wet mud bed on top of the slipsheet. The slipsheet is Protecto-wrap AFM, adhered with their horizontal primer. The experts found small areas (bubbles) of non-adhered membrane when they did destructive testing. We used the same slipsheet in both installations. The slab had 70 days cure.

Bud Cline

I don't see why all of this attention is being directed to the slip-sheet or why anyone could think the slip-sheet is the culprit. Maybe you could enlighten me.

If all the slabs have a tendancy to spall at all the edges why wouldn't the culprit be the stone?

Seems to me the slabs are defective if this spalling is considered to be unnatural, unanticipated, and unwanted.

Are you sure this stone is limestone and not slate? Slate would/could have a tendancy to do exactly what you describe.

D.C.

Bud, the tile is very definitely limestone.
Limestone is considiered to be dimensionally stable, correct? Does stone expand appreciably?
Our company will not install slate flooring anymore without a waiver from the client due to the fact that you cannot seal or bond slate because it is always flaking.
The experts blamed the slipsheet installation because there were pockets of un-bonded membrane, which lifted due to vapor pressure, which lifted the tiles, which caused the spalling.

Bud Cline

Well I'm always learning in this business and quite frankly.....you got me.

I'm not understanding how a slip-sheet as lightweight and flimsy as Protecto Wrap is could be the culprit here. I'm not defending the slip-sheet but I'm also haveing a hard time believing it.

Maybe if freeze-thaw were an issue, but I'm assuming this is not the case. And even then the bond of the Protecto Wrap still couldn't be held accountable. Under the conditions of hydrostatic pressure I don't think you could point to the slip-sheet.

Those tiles are fairly large and even vapor emission haveing the ability to lift the stones puzzles me. I'm just not so sure.

Yes, limestone is considered fairly stable but of course all things expand and contract some. I would lean more towards the stone itself being the culprit, more specifically the sawing methods.

Do these (so-called) "experts" have a vested interest in any of the products?

Are these stones grouted or are they butted and have no grout?

D.C.

Bud, thanks for all the replies. I too am trying to get it.
The AFM is not flimsy. It is a waterproofing and AFM. It's pretty thick. I can see how it would trap the vapor from the "wrong" side, and I am aware vapor can build a head of pressure, but can't fathom how it could lift the stone.
I had originally hoped you guys would all say Protecto wrap...what were you thinking...that stuff's failed on tons of jobs??? Guess that's out. If anything, I'd like to find the culprit and not have it be the fault of the hardworking craftsmen that put the stuff in, twice.
The tile is butt tight, but does have some non-sanded gout in the joints. there is no freeze here and therefore no thaw.
Whaddya mean "more specifically, sawing methods"....
None of the "experts" to my knowlege have any vested interest in any product except money.

Bud Cline

Maybe "flimsy" wasn't the best choice of words. I in no way was intending to diminish the quality of the Protecto wrap product. In fact, I have only heard good things about Protecto Wrap and would probably use it myself if it were readily available in my area.

I too see where the Protecto Wrap would serve to seal the foundation and I guess it would be possible under the right circumstances to lift an area because of it being sealed but there is still the weight of the stone and gravity, this has to play a part in holding everything down to some degree.

I also don't see where this is on the shoulders of the installers.

Ok, on the sawing methods........
My thinking is that the possibility exists that if the stone was sawn with a blade that was out-of-sinc or warped the blade moving from side to side while rotating could conceivably stress the stone along the edges. THEN, after the stone is installed and being 'butt-tight' to one-another the small amount of movement that would naturally take place would be enough to fracture and spall the edges of the stones if they were rubbing together. This is one I would certainly like to see for myself.

I have seen slate many many times that seemed to have a small amount of surface damage (chips and spalls) on the edges. I couldn't prove it but I have always thought this was from the sawing process. I'll admit slate and limestone are two entirely different things but at the same time I have (easily enough) chipped the face of limestone building stone (wall-stack) with a geologists hammer to enhance the beauty of the stone wall I was building. I am only imagining what this issue may look like.

Sorry somebody couldn't come up with a more difinitive answer for you.

tgeb

I'll take a shot at this.

D.C. since you're in S. Cal. is it possible that the sun hits this stone during the day?
Even with the expansion joints they installed on the second go round, if these 2'X2' stones are touching each other I could see them trying to shove each other around trying to make some space for themselves as they heat up under that beautiful S. Cal sun.

I would think that unlike say a concrete slab which would expand over a greater area, each stone is going to expand individually, needing some space to itself.

What do ya think, maybe?

Tom

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Tom

www.gebcon.com