fresh concrete: how long? [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


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06-28-2008, 05:40 PM
How long does the concrete (basement bathroom floor) have to cure before I can tile it? Tks.

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06-28-2008, 05:50 PM
I think 28 days is the rule.

06-28-2008, 05:50 PM
was this just poured ?

After concrete is placed, the concrete increases in strength very quickly for a period of 3-7 days.
concrete reaches about 80% of it's final strength after 7 days.
it near full cures in 28 days but never eally stops curing over its life.
The one month ruling is what's known as 28 day strength and is a baseline for most commerical concrete work.

06-28-2008, 06:00 PM

I filled in the ~1/2 inch gap around my toilet pipe in my basement bathroom yesterday with mortar mix at 2PM and tiled over it at 9 PM - I thought the
mortar just needed to set up. Is this bad?

Maybe I hope it's okay, or should I pop up the tiles around the pipe (which were a pain to cut by hand, lacking a wet saw) and wait a while?


06-28-2008, 06:04 PM
Hi T,

Don't sweat it. It's too small of an area to be a problem in my opinion.

06-28-2008, 06:47 PM
what Dan said, your ok. :)

when you said "concrete" we thought you were referring to concrete concrete.
not a small mortar patch.

06-28-2008, 07:14 PM
Youve been given some good information so far...........Now lets complete it.

Concrete as it cures will SHRINK..........How Much will it shrink???

Well, If this is for example an average Home slab on grade you are likely 42-46 feet in length. Since concrete will cure and shrink 1/2" per 100' of length, youve got 1/4" crack........or 2 1/8" cracks............or perhaps 3 1/16" cracks that WILL SHOW UP 1 day.

I am not saying maybe, perhaps, might...............WILL is the KEY word here.

Will the Slab crack where you want it too..........Probobly not, Murphys law dictates that it WILL crack in the Most conspicuous Place causing the Most possible damage and at the worst possible time.....Likely right before a family reunion or during a Wedding gathering etc.

SO.............ENTER..... The ANTI Fracture Membrane....also Known as Up Yours Murphy!!! ( never did like that guy)

Anti fracture membranes are How you beat the gremlins and insurethat YOU will not be Tearing out cracked tiles only to find out that they No Longer make the tile you own and while you may only need 16 of them, There are NONE in the Known Universe that will be available to Fix your problem.

Your wife WILL throw a fit and then GO SHOPPING.........All Because CONCRETE SHRINKS!!!!

Any Questions??? :D

06-28-2008, 07:26 PM

in his post #4 he said he filled a 1/2 hole around his pipe, not a slab.

good informative post otherwise :)

06-28-2008, 07:30 PM
There's two different posters with questions above dealing with two different situations. The thread owner, Bonus, has the new concrete floor. TGF, the wantabe hijacker, has the hole in the floor. :D

06-28-2008, 08:12 PM
I picked up on the hijack; I just failed to mention it. I think we're all cool now, and we have an example of the confusion that hijacking causes.:D

06-28-2008, 08:26 PM
yes, I'm guilty of hijacking. :sheep: (sheepishly admitted)

I wasn't clear if the OP meant the whole brand new slab, or a new pipe
placed into a channel jackhammered out of the old slab with maybe a foot wide patch of fresh concrete, closer to my deal but still way more than my little patchouli ...

sorry, I'll shuffle back to my own thread now.

thanks for your help


06-28-2008, 10:26 PM
Related follow up question, for reference, if I may ask it here?? :o

With how big a patch should I wait weeks for concrete to cure
before tiling? Cuz when I patched the big hole in the floor from the big
water meter moving extravaganza .... it was about two weeks before tiling

Say,... greater than 1 sq foot? Or only for large areas?

I'll go crawl back to my thread again.

06-29-2008, 12:18 AM
With all due respect to those that crawl.... :tongue: :)

I am going to be pouring a 10'x10' slab which will be 'infilling' against existing old slab. (Existing dirt floor in this corner of the basement) The tile will not extend over the joint between new and old.

Tileguytodd, are you talking ditra or redguard type products? Do I still wait the 28 days before tiling using these products? This makes sense to me, I am familiar with concrete and somewhat with tile. I have only just started the demo on this job, and will likely have the time (considering it's summer and all and I will have better things to do than work).

The only time I have set tile on concrete was outside in LA on old concrete. Always interested in more input. Thanks.

06-29-2008, 07:14 AM
Yes, you must still wait

There are many types of Antifracture membrane, Some are better than others but Any are better than None.
Noble Products - Noble CS ( Sheet type)
Custom Redgaurd - ( liquid type)
C-Cure Pro Red - ( Liquid Type)
Laticrete ( several options)
Mapei ( several options)
Flexgaurd - (Self Sticking Sheet type)

Now, None of these will be worth a hill of beans if You do not follow reccomended practices for field expansion joints.

Direct Sunlight will create a need for closer expansion joints, All day sun beating down on an Installation and you should consider an expansion Joint every 8' - 10' while it is possible to use them much further apart in less sever conditions.
These joints should be filled with a Matching Sanded Caulk....we call these Soft Joints.

Is that enough to keep you busy gathering knowledge for the day?? :)

Ive tagged your thread so will try to keep up with you as I can :tup1:

06-29-2008, 08:02 AM
I picked up on the hijack; I just failed to mention it.Ohhh, just make me look

I was on my phone and couldnt really tell. :twitch:

06-29-2008, 08:36 AM
Ohhh, just make me look

Your like me Brian..............We dont need any help, we can look bad all on our Own ROFL ;)

06-29-2008, 10:48 AM
Thanks, guys. I'll pour the crete this week and then there is lots to do for a month, so I don't anticipate this to be an issue.

06-29-2008, 02:35 PM
Tileguytodd, are you talking ditra or redguard type products? Do I still wait the 28 days before tiling using these products? If you use the Ditra, Rich, there is no need to wait any days at all. If you can walk on the slab, you can successfully install Ditra on it and tile.

My opinion; worth price charged.

06-29-2008, 02:42 PM

06-30-2008, 03:44 AM
Keep in Mind, while Ditra has some antifracture properties, it is NOT a true Antifracture membrane...........It IS an Uncoupling membrane.

I just wanted to make sure that point was Clear.

Noble CS is an Anti Fracture Membrane.
e3 is a member here and A Noble Rep..........PM or Email him for more information.
He can be found in our member directory & sometimes hanging around the Pro's Hangout. He can better advise you on the differences Between Uncoupling and a true Anti fracture membrane & the installation methods required.

Also, It is not advisable to set immediatly on your Ditra, better to wait overnight. Yes they say you can and Yes there have been many successful installations done this way , BUT, there have been a few failures that I question as to wether that Moving around did In fact break enough bond while curing to cause Issues....

To Put it simply, Its Just not worth the risk IMHO until someone PROVES to me that these failures were NOT directly related to moving around on a Matt with curing thinset underneath it & NO other mechanical fastening.:)