Replies

1. 
   xxPaulCPxx | Jun 07, 2010 06:21pm | #1

   I think earlier would be better, as it will steal less water from your mortar while it cures.

1. 
   gamblewood | Jun 09, 2010 12:43pm | #2

   Thanks for the reply,

   i am concerned about moisture transfer from the slab up through the tile. I want the slab to cure properly but not compromise the integrity of the tile grout.

1. 
   calvin | Jun 09, 2010 03:32pm | #3

   I've never had to rush tile on new slab...............

   But I'm thinking something on the bag of thinset says-cured concrete.............

   What does that mean in the scheme of things?

   Beats me, but there's a forum that deals with TILE-JohnBridge.  Check there-might be a whole thread on it.

   Best of luck.

1. 
   SquareStraightLevelPlumb | Jun 22, 2010 06:31pm | #5

   Ditto on the John Bridge site!

   Ditto on the John Bridge site.

2. 
   JohnSprungX | Jun 22, 2010 06:03pm | #4

   28 Days seems to be the answer.

   At least, that's the standard for when they break the cylinders on stuff that has to have a minimum PSI....

   -- J.S.

3. 
   k1c | Jun 22, 2010 06:52pm | #6

   tile on concrete

   I am not a expert in the concrete, but just from common sense point of view, just following the recommendation would be good enough.  For example, if the concrete installer says the slab will be cured in a month, then wait a month.

   One thing I would be thinking about is that concrete slab has a good chance of cracking.  Therefore, I would use Kerdi system in case the slab developes cracks. 

   If you did the pour, go back to the concrete supplier (from truck or bag) and look for recommendation.  Hope this helps.

4. 
   DanH | Jun 22, 2010 06:58pm | #7

   Your biggest concern is that the slab will shrink slightly as it cures.  Most of the shrinkage will occur in the first 24 hours, but I'd guess significant shrinkage will occur for a week or so.

   Also, of course, the slab will release some excess water, but this is usually done in the first 24 hours.

   With 12" tile, though, you need to be concerned about cracks in the slab.  A crack isolation membrane of some sort would be worth considering.

5. 
   Scooter1 | Jun 24, 2010 12:34pm | #8

   Typical wait time would be 28 days for concrete to cure.  It will shrink and bonded tiles will then crack and/or pop loose.

   I would membrane the slab as well. 

6. 
   [email protected] | Jun 24, 2010 06:51pm | #9

   I'd recommend two weeks

   Generally concrete used for a slab should have a minimum of 3000-psi compressive strength, and 99.9% of the movement should be done after 4-days. 

   To give a highly accurate answer, I would need to know mix design details, and the data on the concrete as it was placed, and the curing conditions. 

   The longer it is kept damp the better for ultimate strength. 

   You need to be careful about what, if any, curing compound was used.  Some of them might prevent adhesion of the setting mortar. 

   I agree with the recommendation for an isolation membrane. 

7. 
   BobR71 | Jun 28, 2010 06:46pm | #10

   Tile on slab

   Concrete needs 28 days to cure. As far as the tiling goes you need to wait at least that long and use Ditra mat as an isolation membrane and it needs to be appled with unmodified thin set morter ( very important ). Good luck

1. 
   DanH | Jun 28, 2010 11:58pm | #11

   You think in 28 days we'll have come to a consensus?