Planning New Shower Project [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


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King Arfer
02-06-2010, 10:31 AM
I got the go-ahead from the "boss" to rip out our fiberglass shower stall and install tile. I have ordered the "Tile Your World" book, but it hasn't arrived yet. My amateur experience includes installing a 300 sq ft porcelain floor a while back (using advice from this forum). By the way, the floor is rock solid and still looks great.

Anyway, I pretty much understand the shower pan requirements. I was planning on a traditional wall with half-inch concrete backer. This moisture barrier thing has me confused. Do I put poly behind the backer and make sure the poly reaches the floor pan liner (and nothing else on the backer)? If I skip the poly and redguard the front of the backer, won't it wick moisture up from the bottom and then into the studs?

I was told that if I put poly behind the backer and then redguard the front of the backer, a moisture sandwich will occur and mold will grow. Someone also suggested redguarding all surfaces of the backer (back, front, and ends) and this would stop any moisture migration.

I considered Kerdie, but I am on a tight budget. One wall is an exterior wall if that makes a difference. I researched the liberry but may have not have looked in the right place. I thought I was fairly intelligent until I tried planning tile work.



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02-06-2010, 10:59 AM
Yes, as in paragraph #1, you can put poly or 15lb tarpaper behind the Hardi and it is acceptable. Conversely, you can Redguard or HydroBan the face of the Hardi. Either way (but not both together) is quite acceptable.

Kerdi is, of course preferable (IMHO) as it is totally monolithic and precludes ANY moisture ingress to the structure.

King Arfer
02-06-2010, 11:36 AM
So If I put a barrier behind the concrete backer, it should "hang" below or in front of the pan liner in case moisture runs down the barrier?

02-06-2010, 01:05 PM
The moisture barrier behind the backerboard hangs into the liner. Overlap the up-turned edge of the liner by at least 2 inches.

King Arfer
03-30-2010, 10:32 AM
If I'm putting in a mudbed shower floor, is there a reason why I would not want to put a sealer or membrane over the mortar bed (just before the tile goes down)? It would be in addition to the liner on top of the preslope.

03-30-2010, 10:42 AM
The purpose of the mortar bed is to allow water to soak in and flow to the weepholes in the drain fitting. Water flows through the groutlines and from the backerboard on the walls. The bed dries out by evaporation back through the groutlines, too. If you sealed the mudbed, you reduce some of the drying mechanisms without necessarily eliminating the sources of water. So, your mudbed may not get as wet, but it doesn't dry out as fast. I would rather have a quick drying shower, so that mold and odors have less time to grow.

If you want a surface waterproofing system, you need to make that decision early so you can incorporate the features needed to make it work. One such feature is a connection between the waterproofing memebrane and the drain fitting. The Kerdi system's drain fitting has a bonding flange to connect to the membrane. The Noble system uses a standard clamping drain fitting that ties into the membrane. It has a small mudbed directly around the shower, so less mud needs to drain. The drain to membrane connection is the key in keeping the mudbed dry.

King Arfer
03-30-2010, 10:48 AM
Thanks for the quick response. It does make sense to provide a means for moisture to escape the mortar bed. Is it still proper to seal the grout on the floor, or will the sealer prevent moisture escape?

03-30-2010, 11:07 AM
Most sealers are "vapor transmissible," meaning they will pass water vapor, but keep dirt off the grout. Keeping the grout clean is the only reason for sealing.

King Arfer
04-20-2010, 08:36 AM
I am halway thru reading my copy of Tile Your World, it's very helpful. If I get this right, the preslope dries overnight, the tile bed dries over night, the set tiles dry overnight, the grout dries over night, and possibly the grout sealer goes on a day or two later. That's at least four days right there. Is this correct, or am I missing a secret that you experienced guys know of? It looks like there is only a half-day of work that can be done at any one time (tiling may take two days I guess).

04-20-2010, 08:46 AM

Yes I would say that your on the mark, might want to give the grout a lil more than a day to cure, maybe 2-3. They want it nice and cured. Yes most of your time is spent on prep work, most people don't see the work involved in tile projects cause they only see the surface, kinda like seeing the cover of a book but not reading into it. Prep, prep, prep, then you get to do some tile. Your tile is only as good as what its on top of:wohoo:

King Arfer
04-20-2010, 08:58 AM
I plan on taking a week off for this. I suppose each stopping point (waiting for curing) is a blessing, since I won't get exhausted. I am creating a checklist for each step I have to take, but I suppose there are always unexpected glitches.

Thanks for the quick response!

04-20-2010, 09:01 AM

No problem, yes take your time. When your doing your own project you got no one looking over your shoulder, hopefully! Take your time do it right, take a break and next day do another step. Biggest problem is people are always in a hurry and "haste makes waste" I don't know how to better put it. Good Luck on your project:postitbg:

04-20-2010, 09:48 AM
Jim, the manufacturers put all that cure time into their products so you'll have plenty of time to practice "standing around." Don't waste a second of it! Practice it, live it! Knowing how to "stand around" is what separates the tile guys from, well, everyone else! :D

That, and the out-of-service shower.:D

King Arfer
10-04-2010, 11:56 AM
Does bottom flange of the three piece drain just sit on the subfloor? I thought it would bolt on to the subfloor. If I am off on the bottom flange height (inch too high over subfloor) can I make this up with the preslope thicker around the bottom flange? I'm in the middle of the install right now, and wanted to get the preslope done today. Any help is appreciated!

Houston Remodeler
10-04-2010, 12:03 PM
yes you can make the preslope thicker at the drain. Of course the 1/4" slope is to be maintained. That's pretty normal esp when installing over plywood subflooring. 3/4" minimal, 1" is nicer

King Arfer
10-04-2010, 12:05 PM
Thanks so much. So the bottom flange just rests on the preslope? For some reason I thought the bottom flange bolted to the subfloor.

Houston Remodeler
10-04-2010, 12:27 PM
Your pipes should hold themselves in place with proper blocking, strapping and supports. The flange sets on the mud when you are finished the installation. Use something to keep the mud from falling through the gap between the plywood and the pipe

King Arfer
10-04-2010, 12:31 PM
thanks much, it's my first shower attempt and I really appreciate your help. Best wishes.

King Arfer
10-04-2010, 08:08 PM
Is there a problem with having too much preslope angle? It seems like the water would drain faster with a steeper slope. I got my preslope in today, and it's slightly steeper than I planned. I did a fiberglass shower tear-out, blocking, drain installation and the preslope, and I'm tired. Thankfully I gave myself this whole week to get the shower done.

Houston Remodeler
10-04-2010, 08:11 PM
As long as your top layer over the liner is somewhere between 1/4" and 1/2" for slope, then you'll be fine.

King Arfer
10-04-2010, 08:15 PM
Thanks again C&R. I won't be so tired on the top layer tomorrow, so I will go a little slower and more careful. Have a good one.

King Arfer
11-13-2010, 08:33 AM
I got my shower pan in, everything tiled, grouted and it hasn't leaked after three weeks of use. YAY! Wifey loves the bigger shower and niches. Some trouble with floor tiling, but OK results for first-timer.

I am going to start the floor now. It's a narrow bathroom with a walk-in closet at the one end (closet getting tiled too).

I have a fiberglass garden tub unit adjacent to the shower. The tub has fiberglass sides that extend to the floor. I was going to tile 1/4 inch up to the tub wall and then caulk. I have 3 inch by 9 inch trim tiles (one edge bullnosed) left over, and was wondering if I could use those as a shoe molding and place them on the floor, going three inches up the tub wall. Would I use thinset to set the trim pieces on the face of the fiberglass or will thinset not stick well to the fiberglass? I would still caulk the trim/floor joint. Thanks for any input.

11-13-2010, 09:16 AM
I wouldn't try something like that with thinset mortar, Jim. If I were fixin' to try it, I think I'd wanna use an epoxy adhesive such as Laticrete 300 or 310.

Wouldn't matter much to me, though, on accounta I don't think I'd be inclined to try that. Too much movement likely in that fiberglass tub skirt.

But if I did try it, I'd also be inclined to use a color-matched caulk in all the joints rather than any sorta grout.

My opinion; worth price charged.

King Arfer
11-13-2010, 09:38 AM
Yeah, I sorta thought that that there might be tub movement when it is filled with water (but I guess I forgot about that temporarily), and that will cause cracking of thinset/grout. The linoleum had pulled away from the tub (probably due to movement and water down the side). Maybe I'll just keep is simple and skip the trim pieces. Thanks CX.

King Arfer
11-13-2010, 10:00 AM
I was a little paranoid about keeping a good slope on the shower floor and it has a relatively steep slope, but not dangerous. I did not do any plumbing changes except for the new drain/flange assembly.

The drain makes a lot of noise as the water goes down. The water goes down fast, and I would say even too fast, and it's noisy. Has anyone ever heard of this and is there anything I can do?

Levi the Tile Guy
11-13-2010, 10:40 AM
Never heard of that Jim. How much of a slope did you give your floor?

King Arfer
11-13-2010, 11:36 AM
1.5 inches slope over 36 in run, probably twice what I needed. I was thinking that the water is running to the center of the drain, rather than sliding down the sides of the drain. Maybe I'll experiment with blocking some center holes...I'm sure my wife will be clogging the drain fairly soon.

Levi the Tile Guy
11-13-2010, 11:51 AM
Yeah that is 1/2"er ft. nothing wrong with that, just makes it harder to tile. you can see the steep slope in your pic. Don't know how to solve the noise issue. Like you said give it time and the wife will plug it for sure. (at least mine would):stick: