Found out at a plumbing supply house that my mortar mix is wrong for tile

I was picking up some thinset at Ferguson's in Denver and the guy behind the counter asked what I was laying. He told me my go-to Type N mortar has too much lime for porcelain tile, which I've been using for years on bathroom floors. Has anyone else had their standard mix cause adhesion problems down the line?

3 comments

3 Comments

the_riley12d agoMost Upvoted

Dont tell me that, I just finished grouting a whole bathroom floor with the stuff. Guess Ill be checking for loose tiles in a few months like some kinda paranoid tile detective. Honestly though, Type N has been the honey badger of mortar for me never had a failure yet. But now I'm sitting here wondering if the guy at Ferguson's was just trying to upsell me on their super fancy $60 a bag polymer stuff. Pretty sure my last bathroom remodel with Type N is still holding up five years later, so maybe this is one of those "the plumber said it" situations where its technically true but practically irrelevant. I'll believe it when I see a tile pop loose I guess.

henry_anderson5412d ago

Man, I gotta disagree a little bit here. Type N on a shower floor is asking for trouble in my book, even if it's held up for some people. The problem isn't just the mixing or backbuttering, it's that Type N isn't really made for constant wet conditions or the expansion that happens with tile and substrate. Mapei and Laticrete both have spec sheets that say for shower floors you should be using at least a fortified thinset, and I've seen enough jobs where regular Type N turned into dust after a few years of water getting under the tile. Maybe your friend got lucky, but I'd rather spend the extra $15 a bag on something like Kerabond or a polymer fortified mix than risk having to tear up a whole shower floor later. The Ferguson's guy might have been upselling, but in this case the science backs him up more than the "it worked for my buddy" stories.

craig.olivia12d ago

My buddy used Type N on a shower floor three years ago and it's still solid as a rock, not a single crack or pop. I get the anxiety though, @the_riley, I was the same way after reading a bunch of forum horror stories. I think as long as the thinset is mixed right and the tile is backbuttered, you're probably fine for most jobs unless you're dealing with some really weird substrate. Those polymer bags are nice but I've never felt the need to drop that kind of cash for a standard floor.