Acrylic Alcove Tub Install Framing Issues

[Mr.T]

As I continue to work through fixing issues from the previous contractor, I have a few I'm facing with the bathtub installed (Mirabelle Sitka acrylic). Most of these affect insuring proper prep for tiling vs actual plumbing issues, but this group is always quite knowledgeable.

1) The back edge is warped (picture showing the level clamped). Center of tub would require a 1" furring strip and Front/Rear corners would require 5/8" furring strips on studs to allow for the backer board to come down over the tub lip.
Even though they will be thick, should I just vary the furring strips as required and not worry about it or should I try to "draw in" the lip at each stud with a roofing nail or a counter sunk screw through the lip (I really don't like the idea of pre-stressing the lip).

2) The RH side of the tub has a 1/2" gap to the exterior wall. I have no issues furring that out the length of the wall then adding the backer board. The issue is that the toilet shares that same wall and was roughed in at the proper distance of 12 1/2" from the framed wall. So I'd end up with a final toilet dimension of somewhere between 11 and 11 1/2" to the continuous finished wall. How risky is that in terms of clearance to the tank lid of the toilet?

3) The LH wall only extends past the tub skirt by 1 1/4". Once the end is drywalled and finished that will get me to about 2".
Should I add a stud to give it more depth for tiling down to the floor in that short section by the skirt? It may also be better for the shower curtain. (Think I answered this one for myself).

Any help/thoughts are appreciated. Thanks!

 

[Breplum]

First, vary the wall furring strips to create a continuously smooth surface to go against the tub edges.
Then, add furring strips to build up so you can overlay backing over that very weird, thick "tile flange.
Remove that notched framing on the left side and create a new flat stud, and yes, much better to take tile down to the floor, but not necessary if glass doors are planned.
Expect water to leak at the tub edges so waterproof all the way down to the floor and waterproof the subfloor too.
I have to say, that is one weird flange. Are you sure it is designed for tiling? I think not...why so thick, being thick just makes your furring strips so excessively thick. Always use anchor nail or screw above the top of flange. Maybe they want you to put cement board down to that 'flange' and then not have furr strips at all, but in a shower situation, that just invites water to travel under the bottom edge of the cement board if it ever gets past imperfect grout.

 

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[Mr.T]

breplum,
Thank you for your reply. A few comments:

I agree with you. I am going to vary the furring strips on the back wall to get a continuously plumb and smooth surface. I agree with you that the tub flange is really wide. That coupled with the fact that the tub did not get installed a little tighter to the framing, and that the rough opening is a little larger than needed only exacerbates the issue.

The framing is not actually notched on the left. What you see is a furring strip that I installed to allow for the backer board to be brought over the lip. But after thinking about it it feels like that part of the wall needs more depth. So I may add a stud on the end to get another 1.5". I absolutely plan to waterproof the surrounding area as your suggest.

I hate the idea of bringing the board to the top edge of the lip vs over it for the reason you state above. Even if it means some thick furring. the real problem is that right side. As I describe above, furring it out for the entire wall will end up reducing the gap to the back of the toilet lid quite a bit. Center of the closet flange to the finished wall will likely be around 11 and 11 1/2". I'm worried that will be too tight.

 

[Terry]

There are only a few standard 12" rough bowls that will set at 11.5"

 

[Mr.T]

Terry,

Thank you. I'm sure you've set about 10000X more different toilets than I have. So that answers that question. Looks like I'm either not furring that side out much, or I'm resetting the closet flange (which really is not worth it). Shoot.

 

[wwhitney]

So what's the obstacle to sliding the tub 1/2" towards the wall shared with the WC?

Cheers, Wayne

 

[Mr.T]

Hey Wayne. Reasonable question. Unfortunately, the tub is already set in to a mortar bed and the drain is plumbed and glued (previous contractor). Of course I could dismantle all of that, remove the mortar and re-do it, but that does feel like perhaps a bit much to resolve this.

The tub does appear/feel to be set robustly and leveled properly, so I really would prefer not to go that far. (I already had to re-run all the water lines and level and plumb the studs making up the 2x6 wall with the DWV and water lines that is between the bathrooms). Frustrating but I'm taking it one step at a time.

 

[wwhitney]

One option you have is to fur out the wall as required for the gap and the tile flange, and bring that plane of tile out to match the tub leg on the opposite side, returning it to the regular drywall plane behind the WC using a 1/4 round edge profile tile (probably not the right term, but the cross section is a quarter of anulus). That would work well if the tile goes to the ceiling. If it doesn't, the 1/4 round edge profile would also need to turn horizontal at the top and return to the long back wall of the tub.

Cheers, Wayne

 

[Mr.T]

That is a reasonable solution and the tile will be going to the ceiling. I actually have a window that is right above the WC and near the tub. I can terminate the tile in the manner you described right before the side of the window trim and line it up perfectly symmetrical with the opposite leg of the tub. I think I am going to go that route.

I appreciate everyone providing feedback.

 

[DragonBallz]

That is a reasonable solution and the tile will be going to the ceiling. I actually have a window that is right above the WC and near the tub. I can terminate the tile in the manner you described right before the side of the window trim and line it up perfectly symmetrical with the opposite leg of the tub. I think I am going to go that route.

I appreciate everyone providing feedback.

How did you end up doing with this? My Kohler Underscore tub also has a thick flange. The tub actually looks very similar to yours.

I am planning on using 5/8” wallboard to make it flush or stick out past the flange.

 

[Mr.T]

How did you end up doing with this? My Kohler Underscore tub also has a thick flange. The tub actually looks very similar to yours.

I am planning on using 5/8” wallboard to make it flush or stick out past the flange.

Hello. I am a WAYS away from actually getting to the tile stage. For now, my plan is to fur out the wall and install some kind of edge profile. I might still consider moving the toilet flange so I can then fur the entire wall out he same distance, but I am not at the point I have to make that call yet.