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Cracked Tile Grout Line

4317 Views 35 Replies 15 Participants Last post by  ArtisanRemod
Hi everybody

Quick question, so the job I am on right now with the boss had new ceramic tile laid on top of an old ceramic tile floor that was very stable. Anyways the HO about a week latter had a basement waterproofing company come in to do some work. The next couple of days latter the floor where they had been walking starts to show cracked grout lines and tile starts to feel louse when you walk on it. So we start to cut the grout and remove the lose tile. When we did this it looks like the thin-set was fine because it covered the whole back of the tile. My question is could the tile become lose just because of all that weight on the tile and the constant movement and weight put on it or was our thin-set tile install at fault?
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Got a picture?

What pat did not stick? To stick tile to tile successfully you must use a two part thinset like Kerabond and Keralastic---or a modified that is approved for that job.
I've never heard of tiling over tile. Can you really do that:confused1: ?
I may be able to get some pics, yes we used a modified thinset to bond the tile to tile. Well to me it looked like the tile was cover that was the top layer but there was no thin set on the bottom layer of tile unless that means it was all pulled up. The tile was hard to pull up so that makes me think there was not a thinset failure. I should have added we think the tile did this from all of the buckets of concrete they were bringing in because only the tile in the pathway they took felt louse and had the crack grout line
Got a picture?

What pat did not stick? To stick tile to tile successfully you must use a two part thinset like Kerabond and Keralastic---or a modified that is approved for that job.
From what I have been told and read you can as long as the base tile is still stable, we have done this method a couple of times and still no call backs for cracks
I've never heard of tiling over tile. Can you really do that:confused1: ?
Sounds like there were probably existing issues in the original tile floor or subfloor that maybe you guys didn't see (or ignored). A new tile floor should be able to handle people walking over it holding concrete buckets, so you can't blame them.
The HO did say the joist in that area had a lot of deflection when they were bringing stuff though. Or like you said the tile to subfloor had issues. I am not sure still trying to learn that's why posted question
Sounds like there were probably existing issues in the original tile floor or subfloor that maybe you guys didn't see (or ignored). A new tile floor should be able to handle people walking over it holding concrete buckets, so you can't blame them.
Deflection probably got ya..

What did the waterproofers do? Any mudjacking would probably cause movement as well.

Did the underlying tile fail, or just yours?
From what I can tell they only put in a perimeter weeping tile so part of slab was cut. The underlying tile was only cracked in one spot the rest of the areas we pulled up the underlying tile was fine.
Deflection probably got ya..

What did the waterproofers do? Any mudjacking would probably cause movement as well.

Did the underlying tile fail, or just yours?
Did you guys check loads to see of the floor system could support another layer of tile? Probably not. I don't see how putting another layer on a floor that has deflection issues would ever be a good idea
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Your right that was probably not a good idea the floor was not like that with the first layer that I know of. I also don't feel any movement in the subfloor with the second layer but sounds like there are issues now with the joist since the HO said the joist were deflecting when people were walking through.
Did you guys check loads to see of the floor system could support another layer of tile? Probably not. I don't see how putting another layer on a floor that has deflection issues would ever be a good idea
In my opinion the bond should be so good you can't remove tiles without breaking them. A number of things could have prevented the thinset from bonding to the base layer. Sealer comes to mind, nothing really sticks to it.
got ya, well if you were to clean the underlying tile of sealer what would you use to get a better bond for the thinset?
In my opinion the bond should be so good you can't remove tiles without breaking them. A number of things could have prevented the thinset from bonding to the base layer. Sealer comes to mind, nothing really sticks to it.
I did a couple bathroom tile-over jobs (12 x 12 porcelain) using Mapei Eco Prim Grip for the first time, which is a bonding primer. The existing floors were mosaic, nice and solid.

It turned out fine over all, except that I needed to pop a couple lipped tiles and redo them. They pulled up in whole pieces, applying a heavy, sharp hit with mallet and scraper. My setter had used speedset instead of Ultraflex II, like I wanted. I let it slide, but would make sure to insist on a good modified thinset next time.

As for your floor, sounds like you're on the hook due to poor adhesion/bond. Either wrong thinset, improperly mixed or floors were not clean.
What is the size and span of the joists under the tile?

What exactly were the concrete guys bringing across the floor?

How long ago was the new floor installed?
Size and span not sure but can look on Monday
All I know that they were carrying were buckets of mixed concrete to place around the basement, I would also think a breaker hammer
The tile was completed then about week later the waterproofers were there.
So I would guess about 100lbs a bucket, 2 per guy. That's not that crazy
True just restating my boss's option to the HO why they did that.
So I would guess about 100lbs a bucket, 2 per guy. That's not that crazy
The more I think about it, makes me believe the thinset did not bond to the underlying tile. Correction just found out the original tile was a terracotta. That would go back to what was being said about the tile sealer.
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