My subcontractor installed 3500 sq ft of mexican travertine ( 16″ X 16″ tiles) about one year ago. The entire tile floor was installed on a poured concrete slab. The home owner is starting to notice voids in the grout, particularly in the kitchen area. If you tap on the tile with the back of your hand there is a hollow sound. My immediate conclusion is that there wasn’t enough cement applied to the tile. Is my conclusion correct ? Do I have any recourse with the tile sub-contractor ? Thanks. Kay
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Large format tile with irregular (rough) backs require a lot of thinset, like probably a three eights to one half knotch. The usual drill is to to spread the thinset, embed the tile, then pull it off to check coverage on both the tile and the slab. The installer is looking for no less than 80% coverage, preferably 100%.
It sounds to me that you are correct and there is insufficent thinset. The tiles will ultimately loosen and fall off.
You need to speak to the tile contractor about this, and the floor may have to taken up.
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934
Boris, Thank you for your reply. Apparently some of the installers knew what they were doing but unfortunately some did not. Kay
Kay, is your concern with the grout popping out?? I didn't read about any Tile cracking. I'am not certain what the "Tile Council" specs are for interior tile, though I do belive, that is is not 100% full bond, my memory wants to type about 60 to 75% bond, for interior applications. Though I personnelly, try and shoot for 100%. Yes, I belive your conclusion is correct, though I guessing they used Thinset, not cement. Recourse, well today, regrout problem areas, and bring your tile concerns out in the open with your Tile setter,ASAP. for in Arizona, Subs, are only liable for one year, from date of Final Inspection. General Contractors are Liable for two years. So, depending on your relationship with your Tile setter , time may, or, may not be, of the essence. Best of Luck. Jim J
Hi 44, Thank you for your response. My concern is that I think the grout is dropping into the void where there isn't any thinset. However my main concern is that the tile(s) will eventually crack because of the uneven thinset layer below the tile(s). Kay
Do you mean the grout is falling under the tile, as if the edges weren't buttered? That's a mistake, for sure. Then you also mention tiles sounding hollow--sounds like the tile might have been a bit wavy and the thinset not applied appropriately to compensate. I bet if you pull up a couple of problem tiles you will see what is wrong. I've been out of the biz too long to speculate if it could be solely a grout prob, but I doubt it.
If you can find out which parts of the floor were installed by the novice, and determine that that area is the area affected, you might be able to avoid a full tearout. I've done a few of those tearouts/redo's--the thinset coverage, or lack thereof, was always the problem. Not to say the grout didn't have other probs, but grout was not the major prob.
If the suspect tiles are few and scattered, you might consider selective replacement w/decorative tiles if you don't have enough spares. Good luck!
I agree. Pull up a hollow sounding tile (or one with shrinking grout). Take pictures. If appropriate, show it to your tile guy. Get him to fix it with an experienced tile setter. The tiles won't "drop off" because they are already on the floor but that hollow sound will remind joe homeowner (negatively) of you everyday. What was the substrate? Durock over the subfloor? Could it be contributing to your hollow sound? What was the screwing schedule? Every 6 inches? Can you see screws from below or, if not, removing that hollow tile will tell you even more. It takes what seems like a zillion screws (personally I use stainless--a magnet will tell you) to hold that substrate tight. 3" on edges, 6" grid on the field. It is "sanded" grout--right. Don't forget the sealer when all problems are solved. Thor Hands-on-GC
Tyr, Thanks for your input. All the tile sits on a poured reinforced concrete floor. The concrete sits on grade. It's possible that the kitchen floor wasn't sealed properly which could be causing the loose grout siktuation. Thanks again for your expertise and time. Kay
Kai, Thanks for your reply. I'm sorry if I mislead you. After hearing from all the experts, ioncluding you, I'm 99.99% sure that the "problem tiles" don't have enough thin set coverage. I agree that a complete tear out isn't necessary. There's probably twenyt(20) tiles in the kitchen areas and the other rooms where there are one or two tiles. I've watched the tile sub replace some cracked tiles. It can be quite labor intensive______ not to mention the mess for the home owner. The grout seems to loosening only where the "problem tiles" are. I don't know whats causing this. Some of tiles could be loose. Thanks again. Kay
on top what the others have mentioned you might consider how the slab was finished. If the concrete was finished only with a steel trowel or power trowel the concrete might not have had enough bite to allow the thinset to adhere properly to the concrete floor.
generally a wood trowel or a mild acid rinse gives that concrete enough tooth.
Id be inclined to thin not enough thinset was applied but the above theory might also play into the tile loosening as well.
Hi WmP, I would agree with you except I'm not having the same problem in the other areas of the home. The entire 3000 + square feet of concrete was one homogeneous pour. I'll put my money on the "lack of thin set" theory. Thanks again for your help.It's always good to hear from the experts. Kay