Tiling over bath tub flange

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DougB

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I posted this on the JB forum. But Mr. Red Sneaker had to respond with his usual drivel. You would think by now he would know that I don't want to hear from him. But apparently he knows no boundaries.

I'm ready to tile the bottom row of tile for the bath tub. It's a Kohler, acrylic tub, the flange is about 1" high.

I brought the Hardi Backer board down to within about 3/16" of the flange. Then I caulked the gap with 100% silicone. The Hardi Backer is even (vertically with the flange). Also I'm using Adrex X77, so I don't think that extra inch is going to make a difference - it's 12 x 12 tile.

Should I use thinset on the flange area? Could there be a possibility of a slight movement between the tub and the wall, that would stress the tile?
 

Eurob

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Did you install a 2x4 or similar under the edge of the tub where it meets the wall for support , Doug?

Are you going to use the 8+9 as the waterproofing membrane ?
 

Eurob

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A 2x4 is not recommended

I know , Just don't send the plumber's police after me . If your base is supported properly , there is really no risk to do it .:D

But your question was

DougB said:
Could there be a possibility of a slight movement between the tub and the wall, that would stress the tile?

What type of movement are you expecting ? On a X,Y,Z axis .

You can use 2'' minimum mesh ,Hydroban , followed by the fabric and Hydroban -- bridge the flange and hardi together . Don't forget to use the Latasil in between the tub and the tile .

One more question .....why Ardex X77 with the Hydroban ?
 

ShowerDude

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Doug, in a perfect world you would have shimmed your backerboard out on All of your 3 walls.

This would have made your backer drop right over the flange lip..

Options to save the day but not my plan A?

1.Remove silicone from gap, use a medium bed flexable thinset w/fiber tape to fill said gap , skim smooth,
Let dry , continue w your hydroban and fleece fabric at change of plane to tub deck. Tile and yes use only silicone at deck.

The truth is you may be better off leaving silicone in as it is now if its a fully sealed gap and your hardi is at least sticking out proud of the flange so your 12x12 will drop to the deck properly?


cant see your picture???


The concern is indeed tub wall movement and the thinset cracking .

Hence a 2x4 ledger with a healthy dose of silicone is IMO always a good addition to setting a tub in mudbed or foam, i call it smart overbuilding.

Good luck
 
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hj

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Without a 'ledger' board, the tub is sitting on the floor and the wall tile si above the tub rim, but there is NOTHING to keep the floor and wall for moving in different planes. At least with a ledger board the tub rim HAS to move in unison with any wall movement.
 

Jadnashua

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He has learned this all on line you know.

I guess the projects I've done and the workshops I've taken, the extensive reading I've done on manufacturer's documentation, along with the close to 10-years of listening to pros on how they do things and why, count for nothing...

Just a few months ago Jim helped me understand how to go Poo properly in Turkey.

If you care, John posted a picture of a sign, showing a pictograph saying do not stand on the rim of the (western style - i.e., what we typically use in the USA) toilet, and I said that was not uncommon in that part of the world...lots of cultures do not sit to poo...they squat, which, when you encounter a western style toilet, might be confusing to some visitors. But, maybe John didn't know that, and had to twist things into ridicule. Having lived in the Middle East, rather than passing through on vacation like he did, one gets to see and understand things maybe a bit more than a tourist. Footprints on the seat are kind of annoying for anyone, local or visitor, when one encounters them on the toilet...sort of like the do not litter signs...a reminder to be a good citizen and think of others...Unlike John, who takes any opportunity to make himself look good and to make others look bad.
 

DougB

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Doug, in a perfect world you would have shimmed your backerboard out on All of your 3 walls.

This would have made your backer drop right over the flange lip..

Options to save the day but not my plan A?Hence a 2x4 ledger with a healthy dose of silicone is IMO always a good addition to setting a tub in mudbed or foam, i call it smart overbuilding.

The tub is not designed to have the backer board come over the flange. This Kohler acrylic tub is thick, the flange is more than a 1/2" thick, if you run the cement board over the flange, and the tile (which is about 1/2" thick when thinsetted) it will come too far into the tub.

The tub is designed to sit on the floor, and be screwed to the studs - Kohler recommends setting in mortar - which I did.

The thing about ledger boards is that how is one going to get then aligned (so the tub is contacting them on all 3 sides) and also have the tub set level on the floor?? Maybe in new construction?

I'm going to follow John W's advice and put two coats of Hydroban over the silicon seam and on to the flange and tile over that with thinsetting the tile to the flange.

Thanks for the advice!
 
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JohnfrWhipple

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....I'm going to follow John W's advice and put two coats of Hydroban over the silicon seam and on to the flange and tile over that with thinsetting the tile to the flange.

Thanks for the advice!

That's it. You go Girlfriend. LOL

I of course made the assumption when I told you that that you are not setting a 2" sliver cut on the bottom starter course. I would make sure that the bottom tile is at least 6" in height so that you got a good 4"-4.5" of tile affixed to the regular wall.
 

JohnfrWhipple

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I remodeled the 2nd bath about 5 years ago - it has a 3' x 5' shower - that's where we have those 'sessions' :)

##$^ing electrcians. Doug - listen up. You must Christen all Showers in your home. It's a code or something. Kind of like why Wolf's pee everywhere in their turf. It's just a Man Code.

You need to get the Misses in there at least once.

I have a buddy named Ricco. We never signed off on a toilet install until - well you get the idea.

All showers need testing. Some testing is just more fun than others!
 

RCraig

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This question came up in a very timely manner for me - I have more or less the same question, except that the backer board has not yet been installed. My question: Would it be preferable to install the backer board to come down to the top of the flange? Or, alternately, would it be better to shim things such that the backer board can come down over the flange?
The flange in my case is similar to DougB's, except that it is 1/4 inch wide.

Many thanks - the whole reason I am in the mess I am in here has to do with movement. In my case, it was movement in the up-and-down direction (z-axis). It was not noticeable and not even measurable using techniques kindly suggested by this forum. However, it was enough to let water through, right at the position being discussed in this thread.

Many thanks for any advice that would be useful to me.
 
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JohnfrWhipple

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RC the industry guidebooks all want the over lap. Yet I have never seen it done.

I make this call on a job by job basis. Perhaps if you could show me a few pictures with a scrap of cement board held tight to the wall studs we could all get a better idea of what we are up against.

If you can not post pictures then email them to me and I'll do it for you.
 

RCraig

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Ok, thanks so much. I will see if I can get a decent picture tomorrow and upload it.
From what I can understand, I have a problem from even before putting up the cement board, because the wall studs are not even on the front side. That wall had to be moved over a few inches to fit the new tub in. My impression, now that I am learning a little more, is that the wall studs on the front side of where the tub is are quite gerrymandered.
 

DougB

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Gerrymandered...... WTF - Time to goggle

OK even with a goggle search I still have no idea what you mean....

Gerrymandering is a term used when assigning voting districts. If you layout the district correctly - your party will get elected. Sorta means - all over the place. Gov Gerry in Taxacachuetts redistriced voting - the shape of the district looked like a salamander - thus Gerrymander.
 

DougB

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Now as an engineer - I thought the x/y was horitontaly/vertical. The z axis is the cross product :)

All kidding aside. Just get the cement board to come forward 1/8" beyond the face of the flange. Between the silicone caulk (at the cement board / flange joint) and the waterproofing over that ( John's advice ) It looks / feels very sturdy. As I said overlapping the tub flange with the cement board justs looks dumb - after the tile, there is hardly any 'deck' around the tub, I've never seen an installation like that.
 
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DougB

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Here's a picture:

Tub_Flange.jpg
 

JohnfrWhipple

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This new way (My Way) of waterproofing this seam forces you to use a topical waterproofing approach.

You can not waterproof the board this way and skip the topical waterproofing system.

Thanks for sharing Doug.

Did you use any of the reinforcing fabric? Maybe a little drywall mesh for fun?
 
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