Removing dried thinset from waterproofing in shower
We’ve been retiling a shower (our first time). We used the Duroc shower system for waterproofing. After removing the ledgerboard we installed to support the wall tiles, we discovered that some thinset had oozed down behind it and hardened. Before we can put in the bottom row of wall tiles we need to clean off that hardened thinset. Gently tapping with a chisel hasn’t worked. We’re concerned about poking a hole in the waterproofing fabric. We’ve also tried prying up under the thinset, and scraping across the top of it. None of these attempts do much. The scraping produces some dust, and probably would eventually work.
What approach should we be using to get this stuff off the waterproofing fabric so we can finish the project? It varies from about 1/4″ by 1/4″ by a few inches to just a little chunk here and there.
Thanks.
Replies
Use a dremel with solid carbide grinding bit. You can find these at any big box hardware store. Use a respirator.
Resolved: Removing dried thinset from waterproofing in shower
As down Maine humorist Tim Sample would say, "Slick as a smelt."
Thanks for the Dremel idea. It worked well. I bought the Dremel tool several months ago at the beginning of the project so I could use their diamond disks to cut the old cast iron drain pipe from the inside, below the drain. I used it again to cut the hole for the shower valve, since we used porcelaine tile. And now I've used it to grind out the excess thinset, although not with the diamond disk, but with one of the carbide grind wheels. I think that tool has paid for itself on this project.
While we don't have any other tiling projects lined up for the future, if we ever do, how do I keep the thinset from oozing down behind the ledgerboard? Or, if it's gonna ooze anyway, could I put some painter's tape on the waterproofing membrane before putting up the ledgerboard to make the clean up easier?
Thanks again for the excellent idea.
Actually, thinset shouldn't be oozing anywhere. The better you get, the less issue you will have. Good trowleling technique is key, but it takes practice. Your thought of using painters tape in the interum is a good idea.
Actually, thinset shouldn't
Thanks. We'll keep that in mind if we ever do this again.