efflorescence with A/C [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


View Full Version : efflorescence with A/C

scott anthony
06-21-2009, 08:31 AM
Just wondering, grout seems to be one of the biggest problems we have.
Being a residential installer in FL in the summer we have people cranked down on the A/C often.
We did 1400 last week with TEC and had decent results but still had minor blotch's, really nothing to worry due to the color was a bit light to begin with.
The A/C was cranked down to 76 during grout, and I have a felling that when grout dries to fast this happens. I just don't know, just like the red body clay tiles that's sucking the moister out of the grout to fast causing same results.
Has anybody ever tried to mix per direction on the bag, that's funny one.
2 quarts per bag, impossible, and they know it. At this time we are mixing so thick we can barley work with it.
From now on we a working with a 82 temp and see if results change, lord knows we have tried everything else.

Sponsored Links

06-21-2009, 08:53 AM
Scott do you mix it long enough. I use 2 qts and mix for 5 minutes . I like the results. Besides a little thicker makes it easier to clean for me with less haze.

06-21-2009, 09:19 AM
I know its alot but have you tried covering the grouted area with plastic to slow down the curing

Brian in San Diego
06-21-2009, 10:30 AM

I believe the problem you may be experiencing is not the temperature so much as the dehumidification that occurs in the A/C process. I would think that dehumidifying could cause problems for you. I think your plan to grout at higher temperatures should work for you.


06-21-2009, 10:31 AM
I would say with the cooler temp it would dry slower then the hotter 82 temp.
how are you coming to a conclusion its drying faster with the AC on ?

The Kid
06-21-2009, 11:40 AM
is this on concrete? could be minerals from the slab leaching through.:scratch:

06-21-2009, 12:33 PM
The humidity within an air-conditioned space is a lot lower because the A/C removes moisture from the air as it lowers the temps. This creates accelerated moisture vapor movement - in this case from the wet grout to the dry air - causing accelerated drying.

Another big reason why it is always prudent to install moisture barriers under tile in areas where air-conditioning is prevalent.

scott anthony
06-21-2009, 01:32 PM
Thank you for the suggested replies, once again I appreciate all of those who continue to help each other in ongoing voyage for perfection.
All or most installs are on a clean slab concrete approx 3 to 10 years old. I wish we a grout test analyst chime in here if there is such a thing, heck I guess we all are.
Once again thank you.

06-21-2009, 03:25 PM
thanks Adrianna,

I like grouting with the air on and don't have problems, in fact I don't have grout color problems when its a new house and its 93 outside.

mostly all the work Scott or I will have down here is on a slab.

Brian in San Diego
06-21-2009, 06:58 PM
I guess i shouldn't have used a technical term like dehumidification when it could be explained as removing moisture from the air. :shades:

06-21-2009, 07:26 PM
your the AC guy.......what do we know :D

I call it "unhumidified"

06-21-2009, 09:03 PM

Have you tried laticretes' Permacolor yet?

06-22-2009, 07:07 AM
Scott, I've wondered the same thing after grout jobs getting splotchy.

I don't wonder anymore. I open a window if I can and shut the vent in the room.