Hardibacker gap over Kohler "flange"? [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


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09-07-2009, 03:46 PM
Hi All,
Doing a full bath remodel and it is now stripped to the studs around the window over bath. I am installing a replacement vinyl window in my tub alcove before CB and tiling . I plan to use tarpaper vapor barrier and tilt the CB and tile slightly for the sill.
The replacement window will sit INSIDE the existing aluminum frame, so I have to make the rough opening smaller by building up the rough frame.
Which is a better way to do this? Have the CB and tile go UNDER the new vinyl frame? Or ABUTT the new vinyl frame?

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09-07-2009, 03:57 PM
seeing as I always get there after the new window. I have always butt my board up to the frame. bead of silicone.
I would think that would be the better way sealing the window and building the shower completley inside.

09-08-2009, 01:33 PM
That way makes the seam between the window and CB/tile vertical.
Doing it the other way that seam would be horizontal, as in the drawing. Does that make a difference?
In SoCal, so more worried about the shower leaking than the window.

10-12-2009, 05:08 PM
Hi All
The Kohler villager has hardly any flange - just a kind of 1/8" rising lip. With tub and CBU flush to the studs, how much gap between hardibacker and the top of this semi-flange? (1/4" seems kind of a lot - can stick a finger through because of the angle...)

10-12-2009, 05:43 PM
Are you talking about a tub? or shower pan? I'm a little foggy about what you are referring to.

10-12-2009, 05:43 PM
I believe the instructions say a 1/16 gap and then filled with silicone.

If you are going to be using this with a shower head, you should install a moisture barrier on before putting the CBU on and this moisture barrier should overlap the flange.

Another way, is to use Kerdi over the CBU and have it overlap the flange.

10-12-2009, 05:49 PM
Welcome, Daddio. :)

If you'll keep all the project questions on this thread folks'll be better able to see what you're working on and what's been previously asked and answered. We can give it a more generic title any time you'd like to suggest one.

10-12-2009, 09:30 PM
Thanks guys. This is my first bathroom remodel, and it is in a house where I repaired and beefed up the subfloor after previous water damage. So trying to be extra careful.

This Kohler Villager is a standard size cast iron tub. I am installing it with a shower. I used aquabar B as a vapor barrier, then the Hardi, then planning on 12" travertine in the enclosure and on the floor.
So a 1/16" gap seems the way to go?

10-13-2009, 06:24 AM
Your ultimate goal on the shower/tub is to have it, where if you used the shower with only the moisture barrier on ... all water would end up in the tub.

The 1/16 gap is per Kohler's instructions.

I know you beefed up the wood sub-floor. Have you used the deflecto link above (in darker blue area) to see if it is beefed up enough for Travertine?

10-13-2009, 09:26 AM
I just installed the Villager a few weeks ago. I routed a 1/4" notch in the studs where the tub hits the wall and brought the CBU below the lip of the tub. Before I tiled, I ran a bead of silicone in the gap. After I finish tiling, I'll run another bead in that gap.

Hope this helps.

10-14-2009, 12:07 AM
thanks again. I will lower the hardibacker to a 1/16" gap over the tub. Vapor barrier spills into tub. Tile should come down over flange with a gap for caulk

For the floor, the deflectometer is inexact because the floor is not joist and subfloor. It is tongue and groove 2x8s over 4x6 beams spaced 48" on center so it relies partly on the 2x decking for stiffness. I replaced some rotten and cut boards and added supplemental 2x6 joists parallel to the beams to make it 16" on center under the tiled area. So,

Thank you for using the John Bridge Forums Deflect-O-Lator :-)

For joists that are SYP or Douglas Fir, in good condition, 5.5 inches tall, 1.5 inches wide, 16 inches on center, and 6 feet long between supports, the deflection calculated is 0.086 inches.

This translates to a deflection of L / 839.

Since the maximum deflection for tile is L / 360, and for natural stone is L / 720, your floor is rated for Ceramic tile or Natural stone, Congratulations!

anyway hoping for the best!

10-14-2009, 12:33 AM
OK, another vapor barrier question:

I have read that the bottom of the vapor barrier should be attached to the tub flange with tar. (Same sources says tar should be used on seams and stud staples.) Is this too old school?

It does seem a good idea to glue the edge of the vapor barrier right to the tub to keep it in place. Would tar, silicone caulk, or something else work for this (with Aquabar-B)?

11-20-2009, 07:17 PM
OK, Got the window and all the waterproofing aquabar up in tub surround.

Now jsut discovered I should shim out the showerhead wall 1/2" for better faucet fit.

Can I add strips of 1/2" hardi as a shim between the waterproofing and the hardibacker sheets? (Otherwise I would have to take down waterprrofing and hardibacker on the backwall)

11-21-2009, 06:09 AM
After hanging the vapor barrier and hardibacker, I discovered I should shim out the showerhead wall 1/2" for better faucet fit.

Can I add strips of 1/2" hardi as a shim between the waterproofing and the hardibacker sheet?

11-21-2009, 07:28 AM
Yes,but they may break up as you screw through them.

11-21-2009, 09:09 AM
Daddio, let me ask you once again to keep all your project questions on this thread where I've combined your previously merged threads. Makes it easier for folks to keep up with what's been previously asked and answered.

I would recommend you install your wallboard shims behind your moisture barrier and I would recommend you use plywood rather than narrow strips of Hardibacker for the reason Stoner mentioned.

My opinion; worth price charged.

11-21-2009, 09:44 AM
Thanks, and sorry about the stray post

11-22-2009, 12:09 PM
Instead of shims, could I just do a double layer of 1/2" hardibacker on the whole wall?

seems simpler than cutting shims, redoing vapor barrier, corner, etc, at this point.

11-22-2009, 08:12 PM
Sure doesn't sound simpler to me, but it's up to you.

Think you're gonna find it difficult to locate fasteners sufficient to the task for one thing. Gotta be able to go through two sheets of Hardi and then hit enough wood for actual fastening.

I suppose a fella could do that, but I sure wouldn't. Way too easy to rip some plywood and stick it on them studs with a little construction adhesive and some screws or nails. Hang another sheet of poly or some felt and your CBU goes on just like the manufacturer prescribes.

Is what I'd do. But is not my project, eh? :)

11-23-2009, 01:27 PM
OK, will do plywood.
Since the cbu is already up on the back wall, this would make a 1/2" extra fold in the vapor barrier in the back corner. Is that ok or should I take down the backwall cbu and trim it shorter??

Moderators, could we rename this "Daddio's verrrry slowww first bathroom remodel?

12-10-2009, 10:06 AM
Hi All- Update and question on worlds slowest bathroom project. Now tiling with 12" tumbled travertine.

On inside tub surround corners:
Should I abut (overlap) the tiles (leaving a 1/8" gap for caulk)?

Or cut them both 1/4" short to leave a gap? Seems if you leave a 1/8" gap on the edge that shows, that would leave a > 1/4" square hollow to caulk. Is that desirable?

Also, should the cut edge be bevelled to help caulking or square?

12-10-2009, 09:19 PM
You can cut or install them short if it helps layout, otherwise overlap and leave the 1/8 for caulk.

01-31-2010, 11:45 AM
OK, this is a classic problem - The plumber roughed-in the closet flange on top of the subfloor. So the top of flange will be about 3/8 below finished floor when I tile.

I have enough play in the pipe to unscrew and raise the flange without cutting it off. I can do it easiest by inserting two C-shaped spacers (the thickness of the hardi + tile.)

Should I get those plastic spacers from Set-rite or Oatey and snap them in half?

Or just cut the spacers from plywood?

OR, leave it all alone and use an extended wax ring?

01-31-2010, 12:15 PM
These set-rite spacers go under the flange, but not sure if they have them around here - is plywood good enough?


02-18-2010, 11:40 AM
How long does Stonetech Enhancer Pro take to dry on a tumbled travertine floor before traffic is ok? I grouted bathroom floor wednesday and the wife invited people over for Sunday (would be nice to have guest bathroom).

If I give the full 72 hours for the floor grout to set, that leaves only 1 day for the Stonetech sealer-enhancer to dry. Is that enough? Sounds like I should not cheat on the grout set time, right?

Or is the smart thing to wait until next week to seal? If so, how to avoid stains meanwhile?

P.S. Based on advice here, I cut out the old closet flange and reset it on top of the tile.
Finally in the home stretch on this bath!