# Ceramic Tile In Basement



## allworld (Dec 16, 2007)

I am having a problem with laying ceramic tile in my basement. I am laying down directly to the concrete flooe. It is only a 3'x4' area at the door entry. I used some old mortar that I had and set the tile. After a few days about 5 tiles had a hollow sound when I tapped on them so I pulled them up and reinastalled them with new mortar. I am still having the same problem. Also seems like the mortar is not drying after days when I pulled up the tiles it was not solid mortar.


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## ToolGuy (Dec 16, 2007)

When you say 'new' mortar, do you mean new from the store or a new batch of the same 'old' mortar. Old mortar should never be used except as landfill. 

Assuming you mean you bought new mortar...

Is the mortar adhesive hard even though it's still wet? If so, you're using a non-latex modified type mortar. If the tiles are not sticking you are probably mixing it too dry. I generally mix mortar type adhesive so it's just thick enough to stand up when spread with a notched trowel. 

If the mortar you're using is latex modified, either by adding liquid latex or if the latex is already added to the mortar, it must be able to dry. Latex modified mortar does not set like regular mortar. Apparently the concrete is sealed or otherwise not porous enough to allow for drying.

Finally, how soon are you applying the grout. I generally let mortar adhesive dry for a couple of days before grouting. On a cold floor I might give it a lot longer, maybe 3 or 4 days.

Also, can I safely assume nobody is walking on it before it's fully setup? Sorry, but I have to ask.


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## allworld (Dec 16, 2007)

Nobody is walking on the area. I purchased a small box of mortar from Lowes and replaced the tile today. It still sounds hollow but I will give it a few days to completely dry. I noticed also that it is porcelin tile not ceramic. Do not know if there is a special mortar for porcelin but Lowes seemed to stock only one type of mortar. I have not grouted it yet just trying to make sure it is all solid before grouting. I have done about 4-5 tile floors before but none in the basement. I hope to have this done before Tuesday because carpet is being installed.


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## ToolGuy (Dec 16, 2007)

I'm not sure but I think the porcelain may be causing the problem. I know stone and marble require special mortar because they're not nearly as porous as ceramic. This is the case with porcelain as well. I hope it works out this time around but if it doesn't you should try a tile supplier and ask their recommendations. 

I'm not surprised it sounds hollow when first installed. I always notice that when laying larger tiles and it used to concern me, but never seemed to signal a potential problem. 

btw, are you using any sort of additive, like latex or anything? Or do the instructions mention anything about using additives?


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## allworld (Dec 16, 2007)

I am not using any additives.


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