Remove Dried Thin Set From Shower Pre-Slope
 

Gentlemen, I'm remodeling a small shower in a property I own. I built a new pre-slope for the shower out of deck mud and it came out perfect. The tile I'm using for the shower floor is a flat river rock in 13 inch by 13 inch sheets. I laid out the tile on the shower floor prior to applying thin set and made the necessary cuts to them and had everything perfectly aligned to the shape of the shower. I applied the thin set and started laying the tile, but when I got to about the 4th 13 by 13 sheet of tile I noticed that my alignments were slightly off. And then I did something really stupid. I picked up the first 3 sheets of tile I laid, and rather than scooping up and applying a new coat of thin set, I simply laid the sheets right back down. About 5 hours later it hit me how stupid that was. 24 hours later I checked the tile and sure enough those 3 sheets did not set in the thin set. I could literally just grab the 3 and pull them right off. The rest of the tile job is fine. So my plan is to remove the dried thin set in the areas of the tiles that did not stick and then do the job over again. Is there an easy way to remove this thin set? I've started scraping it off with a scraper but it's knuckle busting work. Just wondering if there's and easier way to do it. Thanks!

If there is an easier way, Chris, I sure can't think of it while also preserving the mud bed.

And the longer you wait the harder it gets.......

Welcome back, Chris. :)

You say you made a pre-slope and had a problem setting your tiles on it. I'm confused. Why would you be setting tiles on the pre-slope?

Did you not install a waterproof liner on the pre-slope and a second mud bed on top of the waterproof liner?

CX I'm just using the wrong terminology. I placed a waterproof liner on the pre-slope then laid the top layer of deck mud on that. I placed the tile on that top layer. The shower floor, minus the tile, is done correctly. I actually had a plumber comment on how good a job I did with that part. I messed up with about a 13 inch by 39 inch section of the tile. The rest of the tile job is fine.

Chris, is this the same project as this one, or are you on a different one now?

There’s a tool called a ‘rub brick’ that you can buy from any box store in the masonry section. It’s a block of abrasive material with a handle on it. The abrasive has no problem grinding away thinset, as it’s like 20 grit sandpaper on steroids. Only problem is grinding away too much and digging into the softer mud bed. Rather than just rubbing the tool back and forth like a block of sandpaper on flat wood, I’d swing the tool around in an arc to match the curve of the pan to help from digging into the mud bed.

:)

KMan, no this is a different property. I've moved from that house. That shower came out good though.

Tool Guy that's exactly what I was looking for. I have a small grout saw that eats right through the thin set but it's so small it would take forever to use. I was going to go to the hardware store to look for something similar but significantly larger. I'll look for the tool you suggest. Thanks!

That's what I was hoping you meant, Chris. Worst case, you just break out that top mud bed and do another. Easy enough now that you've mastered the process.

My opinion; worth price charged.