# tiles didn't stick



## bnilsson

I just laid a tile floor and they didn't stick. I used 1/4 trowel and laid thinset under Hardibacker board. Then used 1/4 trowel to lay thinset before I set the tiles. 24 hours later I was able to easily pop all tiles with my fingers or a screwdriver. There was very little thinset on back of tiles. What did I do wring and more improtantly how can I fix it? All thinset is still on backerboard.

I just laid tiles and they all popped back up. I used 1/4 trowel to put thinset under backerboard and screwed it down. I then used 1/4 trowel to lay thinset to place tiles. All tiles came up easily with my fingers or a screwdriver. The thinset only stuck on a few spots on the backs of each tile. All thinset is still on backerboard. What did I do wrong and what do I do now?


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## JazMan

You forgot to tell us what materials you used. Specifically the type of tiles. Were they a soft bisque glazed ceramic for floors? Typically the clay is brown or reddish. Or are they porcelain tiles, which is a harder type of ceramic. Typically porcelain tiles' bisque is off-white, but it may be colored to match the tile color. Or did you install mosaics. Mosaics might be porcelain or natural stone. Then of course it might be natural stone tiles. 

Also need to know specifically which thin set mortar you used. Also describe the consistency of the mix and spreading technique. 

Jaz


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## tacomahardwood.

Use a floor scraper and scrape the mortar off the floor , scrape the tiles .Before it gets too hard , Maybe you did not use the right mortar , Read the bag it should say it's for ceramic or stone tiles , Maybe the mortar was faulty though I have not had it happen , If you let the mortar dry too much before putting the tiles down it will not stick , and you have to let the mortar sit 15 minutes then mix again , Next time if you are new at this set a tile and pull it immediatly and see if it is sticking to the tile , Morta has to be mixed kinda stiff , stiff enough to stand up aand not flatten , But almost wet enough to dribble or lay down a bit ,
I think you used to dry of mix , Let it sit too long before applying the tiles , Or the mortar is not campatable with the tile type ,


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## bnilsson

The tiles are ceramic. I used Laticrete thinset mortar and am almost sure it was the right stuff. I bought a bag of laticrete mortar specifically for laying under the backerboard and the other bag for tiles. I am 99% sure I had used the correct stuff. Can't say for sure, the bag is already gone. I also used Laticrete Megabond additive to mix with it instead of water. 
When I mixed the mortar it was the consistency of Peanut butter, but was in no way runny or very wet. I would stick my finger in it and get a clump and it would stick to my finger. I would mix enough to do about 15 tiles. By the time I would get to the bottom it was getting pretty dry, but I thought it would be okay. None of the tiles stuck well, even the ones that I had laid immediately. I believe I may of used to dry a mix.
Mortar has sat now for probably 32 hours and is completely dry. Will I be able to scrape it off and then lay it again on the backerbaird or will the backerboard be to dirty now for a right mixture to stick to it. Thanks


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## Bud Cline

Without knowing what thinset products were used we wouldn't know if mixing with an additive was the thing to do. It doesn't sound like it.

Did you clean the dust off the backs of the tiles?

Mixing additives doesn't necessarily always make for an improvement/inhancement of the thinset product. Why did you use an additive?


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## poppameth

Is it well bonded the the Hardiebacker? Sounds like the HB pulled all the moisture out of the thinset. I usually run a wet sponge over HB before laying the tile just to make sure it's hydrated enough to leave some moisture in the thinset for the tile to bond to. HB loves to suck the moisture out of thinset.


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## tacomahardwood.

I would say go to the store and try to find the mortar type and read it , Or look at the reciept , It sounds that you didn't read the bag and threw it away , If you knew it was campatable you would not be thinking , It usually pays to make sure you have compatable products before starting the job , 
EXAMPLE , Was on a job and someone used dark colored thinset beneath onyx stone , [NOT ] compatable the mortar showed through and calico striped the very expensive onyx , SOME ONE DID NOT READ THE BAG .it says not to use it for stone ,


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## Bud Cline

MOST thinsets on the market these days are "modified" in some form. You must go out of your way to buy unmodified thinset in most cases. Unmodified thinset is a lot less costly than modified and this is what draws people to it I'm sure.

You can always use additives with _unmodified_ thinset to beef it up and make it a modified thinset. In some cases this technique produces a very superior modified product.

To add additives to _already modified_ thinset can be a huge mistake and can wreck the chemistry of the already modified product. I know of no industry recommendations that suggest the use of additives with modified thinsets but I'm not familiar with everything on the market. I'm not saying this is the case with this tile-failure issue but now seems like a good time to warn those that don't know.

I guess the point is (as is with everything), one should *READ AND FOLLOW THE MANUFACTURERS RECOMMENDATIONS. *After something has been screwed up is not the time to start researching and looking for answers.


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## bnilsson

Thanks for all the comments. I am sure it was the right thinset and additve. I used it before without any problems. It was Laticrete thinset for laying tile to backer board and the additive was Laticrete Megabond. I bought it at Lowes. When I pulled my tiles up I could see all the 1/4 grooves. They just looked like the had been smushed down and didn't adhere to tile at all. 

I plan to scrape (chisle) the thinset off of the backer board as best I can and then do it over. I am almost sure the thinset was not wet enough along with the HB taking up moisture made my thinset entirely to dry. 

Will I run into any problems by trying to apply the thinset again on the backerboard after the existing thinset has been taken off. I am sure there will be some spots that are impossible to get completely off.


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## Bud Cline

> Will I run into any problems by trying to apply the thinset again on the backerboard after the existing thinset has been taken off.


No problem what so ever, just be sure to wet the backer.


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## bnilsson

I bought a chisle today and had taken tommorrow off with the Holliday, I will be scraping up the thinset. Thanks for the advice. Hopefully I will be sending another message two days from now stating that I just stepped on the tiles and this time they are fine. Thanks


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## JazMan

Even if the mix was too dry, or you used the wrong thin set, I don't know how it's possible to not have at least some of the thin set bond to the backs of the tiles. 

I'd like to know more, especially how the tiles were set into the mortar. Were they just set on the mortar? Were they tapped into the mortar? Were they slipped to n flo or what? 

How is it that you do not know which mortar you used? You have a receipt, the store is still around with the same products on the shelves, most likely. 15 tiles at a time? WOW, why so few? That could take a long time to do a simple job. Remember it takes at least 15 minutes just to mix each batch. 

Jaz


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## Snav

Here's the technical info for the products used:

Laticrete Megabond:
http://www.laticrete.com/Portals/0/datasheets/lds6960.pdf

Laticrete Megabond Additive:
http://www.laticrete.com/Portals/0/datasheets/lds6950.pdf

Hardibacker:
http://www.jameshardie.co.nz/brochures/1237937758_74467100.pdf

Ok - read up and make sure those are the right products to use/that you used.


Now, in your initial post you state that you used a 1/4" trowel and "the thinset only stuck on a few spots on the backs of each tile. All thinset is still on backerboard."

Exactly how did you apply the thinset?

From what you've written it sounds like you *just* put the thinset onto the backerboard and then pressed the tile onto the thinset. Did you spread a bed of thinset on the back of the tiles before applying? Did you apply adequate pressure to each tile to press them firmly down?

You should apply your thinset to your hardibacker with a notched trowel, scraping up to make the grooves into the bed: http://www.tileandstonetips.com/trowels.html

Then apply thinset to the back of your tile with the same notched trowel, again, scraping to make the grooves:

Then press the tile into the thinset. Check every few tiles (maybe every 5 or so) by lifting them up after you've placed them into the bed of thinset to see if the notches are gone and squished together - you shouldn't see any trowel lines if it's been set right.

If you see trowel lines in place then you might need to use a larger notched trowel (with 1/2" teeth instead of 1/4") or apply more thinset to the bed and more thinset to the tile.


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