My bathroom tile job in Phoenix went sideways when the mortar set way too fast

I was laying subway tile in my guest bathroom last summer, and the bag of mortar I bought said it had a 45 minute pot life. Maybe it was the 110 degree heat in my garage, but it started getting chunky after like 15 minutes. I panicked and tried to add more water, which just made it worse and ruined a whole batch. I ended up having to scrape off a few tiles I'd already set and mix a new, much smaller batch inside with the AC on. Has anyone else had mortar or grout cure way faster than the bag says, and how do you deal with it?

4 comments

4 Comments

foster.tessa3mo ago

Everything these days seems to work faster in the heat... even the stuff that shouldn't.

ivan_murphy803mo ago

Tell me about it. My old truck's engine starts knocking if it sits in the sun too long. Modern tech just wasn't built for this.

the_drew3mo ago

You think the heat is the main problem? I've had mortar set up fast even on cool days because some brands just have a bad mix. The time on the bag is a best case guess, not a promise. You did the right thing mixing small batches inside, that's the real fix. Adding water never works, it just wrecks the bond. A lot of this comes down to picking a better product and not trusting the label so much.

dixon.james2mo ago

Disagree on the brand thing being the main issue. I've used the same bag for months with no problems until this heat wave hit. The stuff in my shaded, cool garage stays workable for ages, but the bag I left in the shed is totally different now. Direct sun on the materials before you even mix them seems to cook something right out of it.