Why does thinset sometimes dry too fast on concrete slabs?

I've had jobs where it sets before I can spread it evenly. What am I missing about slab temperature?

3 comments

3 Comments

Oh man, that's just the concrete trying to get a head start on the curing process without you! It's like the slab is so eager to help it decides to bake your thinset for you. Seriously though, on a hot day that slab is basically a giant heat sink that just drinks all the water right out of your mix. I've had to start so early in the morning it felt like a night shift, just to beat the sun. A good hose down right before you start is the only way to argue with it.

jake3772mo ago

Last July in Texas, my driveway felt like a griddle by noon. Thinset does the same thing, setting up too fast on hot concrete because it sucks the moisture out quicker. What's your usual method for cooling the slab before you work?

jake3772mo ago

Have you tried misting it down first? I used to think that was overkill, but it really is a game changer for slowing the set time.