Bill and Mongo- I messed up laying the tile. Help, please!

14 years ago

A couple of months ago, I laid 2x2 mosaic tile (on mesh) in the shower over the concrete pan. After being sick (flu and pneumonia) for over 2 months, I finally got around to check on it and and found to my horror that most of the tiles were loose and lifting out of the mesh. So, I ended up tearing it all out and scraped most of the mortar out, but my husband said I should chisel it ALL off. When I tried to do that, there wasn't much I could chisel off. My question is, should I try to get all the mortar off or is leaving a thin layer (whatever I can't scrape off) okay? I think I scraped all the potential loose stuff off, but my husband thinks that if it's not all chiseled off, when I lay the tile again, the hold will be weak. He says that even if it seems to be in there good, it will eventually loosen again. At this point, I'm not sure what I should do. I can't seem to chisel anything off without chipping the concrete. I also can barely lift the sledge hammer he gave me, and beside that I can't help think I'm going to make a big mess of the shower pan. Any advice on how to proceed? Should I somehow try and get all the mortar out (if so, how) or is it fine the way it is now to lay the tiles in again? Also, what are some of the possible reasons the tiles didn't hold? As always, much appreciation for your wisdom.

-Chris

Sort by:Oldest

Comments (9)

gbsim1
14 years ago
I'm most definitely not Bill or Mongo, but I'll ask a question for clarification: Had you grouted the tile?
terezosa / terriks
14 years ago
What did you use to lay the tile? Did it come pre-mixed in a bucket or did you mix a cement like powder with water?
Related Discussions
Help! (Bill or Mongo) plumbing dope leached into Cararra marble
Q
Comments (1)
For some reason the posting is not showing up in the forum list. Update. The "grease spot" seems to be less visible after a week of wet baking soda treatment. I am not completely satisfied with the results, but shiver at the thought of tearing out the 12x12 tile and replacing it... Any thoughts on stain removing from the Carrara marble would be greatly appreciated. I will try to post pics this weekend. Thanks in advance for any help!
...See More
Bill & Mongo I have a pitch question
Q
Comments (5)
Welp... If you or your installer are not aware, code requires that should your shower drain clog, that the "area" that will collect water can hold a minimum water depth of 2" before water flows into a non-protected area. The 2" difference is normally accomplished by a traditional curb at the shower door. Now, you can make the entire bathroom a "wet room" that can hold 2" of water. But you'd need to protect the bathrooom floor plus a few other areas; the toilet...the bathroom/bedroom door, etc. If you Ditra'd the bathroom floor, you can make it watertight by using strips of Kerdi on the Ditra seams. Then you'd need to run the Kerdi up the walls, and as previously mentioned you'd need to protect the vanity, the toilet flange, etc. In my area, it's against code to have the shower slope to the shower door and to have a trench drain at the shower entry. The trench drain has to be at a back wall with the floor sloping to the trench. So there are a few things that need to be rectified, depending if you want to be compliant. I'm not certain if what codes apply in your area, but your installer should be familiar with IRC and UPC if they apply. If you want to wing it you certainly can, but if the work will be inspected, or if you plan on selling your house in the future and don;t want to get dinged at the inspection, then you might want to comply with code even if it's no applicable in your locale. Time for din-din...I'll check back later.
...See More
Tile Help - Please! Bill, Mongo et al...
Q
Comments (3)
Looks to me like you're now going to have a small piece at the top of the upper niche once he moves it up. What's it do at the bottom of the wall? PLEASE tell me he didn't start with a full tile on the bottom? If he did, you're now going to end up with that sliver all along the bottom of all the walls. Can you back up and take a pic of the whole thing?
...See More
So Bill...Mongo...if I were going to go to tile school...
Q
Comments (25)
Sure, when I used to use CPE/Noble/Oatey/CPVC, I wrote about their membranes. Matter of fact I still write about them on occasion, but much less on this forum. We've had a slew of threads about PE behind cement board shower construction. If a DIY wanted to try floated mud walls, we'd write about those as well. But it's not generally a DIY-friendly method. When I used Wedi years ago, I wrote about Wedi. When I used Kerdi, I wrote about Kerdi. I prefer cement board over fiber-cement 95% of the time. I prefer fiber-cement over cement board 5% of the time. Each works better for me in certain circumstances. I do think that for moisture control, a topical membrane shower is superior to a membrane buried within the shower wall or buried in the shower base. I don't want cement board walls or presloped mud bases getting wet. I build fairly tight houses, and moisture control is important to me at each and every location in the house. A major point for me is I don't use foam presloped bases. Most every shower is a custom size so packed deck mud works best for me. Wedi told me "...our shower is all inclusive, you use all or none." Kerdi said "...sure, use our foam base or use the membrane over deck mud." I settled on Kerdi as being the membrane for me. Unlike RedGard, it works as a shower membrane and as a steam room membrane. I prefer easy 100% coverage of sheet membranes versus the "I hope I didn't get any pinholes" roll-on membranes. And that's my personal limitation, my personal concern. Kerdi is readily available at the retail level in my area. Kerdi is easily transportable. If Wedi would improve their distribution network they'd make inroads into DIY residential showers. They'd take market share away from Schluter from the builder side of it as well. And there is the big difference. A builder who is set on a product that works for that builder is going to use that product. A DIY person, which is what this forum is geared to, needs to have a retail distribution network in place so they can access these products at the retail level. All this relates to how I build and how the product works for me. So yes, more often than not I do Kerdi showers. If a Wedi guy, or a CPVC guy, or a Kerdi guy, or a floated mud wall guy wants to post, have at it! Heck, how often do I hear about hot-mopped pans on this and other forums? Do I ridicule them? Not at all. It's a regional thing, and I respect that. All are welcome.
...See More
cmc_in_sf
Original Author
14 years ago
Hi All,

No, I hadn't grout it yet (was about to do it after I felt well) and I used powdered CustomBlend standard thin-set mortar mixed with water to lay the tile.

Thanks,

-Chris
bill_vincent
14 years ago
Custom Blend is an unmodified thinset that about the only thing I use it for is for underneath cement board when I'm installing it on subfloors. That said, if the thinset won't scrape up off the pan, I don't see why you can't go right over it. You might want to scrape down any ridges from between the tiles, first, and make sure you can still adjust the drain up a hair to account for the tiny extra height with the extra layer of thinset.
cmc_in_sf
Original Author
14 years ago
Oops, I grabbed the wrong bag. Well, that explains a lot. I'll find the modified thinset. I know it's somewhere in our house. Thanks, Bill!
MongoCT
14 years ago
My primary concern is why are the tiles lifting in the first place?

Was the base ever sealed with anything?

And you said this is a "concrete pan", is this deck mud over a membrane, or are you going over a slab? There's a membrane somewhere under the "concrete", right? Just asking.

The thinset should not be from an old bag that's been laying around for months and months. Old thinset can undergo partial hydration in the bag, weakening the final bond strength. If your thinset is old, go crazy and splurge $15-$30 on a new bag.

The thinset should be mixed so it spreads like soft butter; loose enough to spread, but tight enough so that when you do spread it with a notched trowel, the ridges hold and don't flow out and collapse.

The idea with using a 1/4" notched trowel is that after the tile compresses the thinset, the 1/4" high ridge is compressed to a 1/8" thick setting bed of thinset, evenly coating the underside of the tile.

You want to bed the tiles in the thinset so you compress the thinset ridges down, but you don't want to mash them so hard that you squeeze out all the thinset from between the tile and the substrate.

All that said...yes, clean off the old thinset so that there is no loose powder or clumps adhered to the bed. You want it smooth. You can have a residue of old thinset on it, but you want it smooth.

If youre using Custom thinset, then as Bill mentioned, use a modified thinset for your next attempt. Either VersaBond (lightly modfied) or FlexBond (highly modfied).

My apologies if I'm being too much "Tile 101" on this reply, but even dryset will provide a good bond to a properly prepared base.

Mongo
cmc_in_sf
Original Author
14 years ago
Hi Mongo,

No apologies necessary for giving me "Tile 101", 'cause I can really use a basic tile course!

So, can you please go over what you mean by a seal and a membrane? I know for sure there's poly under the concrete.

And by trying to get as much dried thinset off as possible, I've unfortunately created some divets in the concrete, so now it's no longer smooth. Can I fill those in with thinset, let dry and proceed laying back the tile? That's provided I understand what I should do to properly prepare the floor before doing so. Thank again for your advise and help. I'm so ready to get this project completed.

-Chris
MongoCT
14 years ago
"I know for sure there's poly under the concrete."

Is that "poly" like 6-mil thick plastic sheeting under a slab? Is this a concrete slab you're tiling on or is this a sloped floor created with deck mud?

When I refer to a membrane for a shower floor I'm referring to a 40-mil CPE or CPVS membrane. You put down a sloped floor. Then you put the 40-mil membrane over the sloped floor. Then you put another thickness of deck mud over the 40-mil membrane. Then you tile over that.

The reason I asked bout a sealer is because I've heard of people trying to tile a shower floor directly on a basement slab. The slab was sealed years before, so the thinset didn't adhere to the slab. Which is a good thing, because a basement slab isn't properly detailed to act as a shower floor in the first place.

As to your divots, yes, it'd probably be easiest for you to fill then with mortar and let it cure. That'll give you a nice divotless base to tile upon.
cmc_in_sf
Original Author
14 years ago
Hi Mongo,

It isn't a basement floor. It's new bathroom construction, so it should be correct shower pan construction.

Great, I'll fill the divots with mortar and let it cure. Thanks again for advise. I really appreciate it.

-Chris

Bill and Mongo- I messed up laying the tile. Help, please!

Comments (9)

gbsim1

terezosa / terriks

Related Discussions

cmc_in_sf
Original Author

bill_vincent

cmc_in_sf
Original Author

MongoCT

cmc_in_sf
Original Author

MongoCT

cmc_in_sf
Original Author

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

Bill and Mongo- I messed up laying the tile. Help, please!

Comments (9)

gbsim1

terezosa / terriks

Related Discussions

cmc_in_sfOriginal Author

bill_vincent

cmc_in_sfOriginal Author

MongoCT

cmc_in_sfOriginal Author

MongoCT

cmc_in_sfOriginal Author

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

cmc_in_sf
Original Author

cmc_in_sf
Original Author

cmc_in_sf
Original Author

cmc_in_sf
Original Author