Installing new tub in basement. Not lining up quite like it should. Ideas?


Old 10-26-16, 10:01 PM
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Installing new tub in basement. Not lining up quite like it should. Ideas?

So, i've been slowly working on my basement for some time now.
I am now down to just the bathroom. I just got the drain and overflow situated.
I dropped tub into place to verify drain lined up and ensure all fit as it should.

I got the tub perfectly leveled, but i'm disappointed to see there are some gaps.

I've never set a tub before, but i'm wondering if shimming will be OK and will not be obvious when i add tile to the walls and floor. Any thoughts or ideas?

Here are some pics:

The back of the tub sits flush against the wall on the left to middle, but back right side sits out about half inch. Can this be shimmed or would i have to tear out/redo framing? If framing, i would have to yank top and bottom plates. The wall is straight. I suspect tub isnt 100% straight. so, can i just shim before I put hardibacker up?
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Now here is the front of the tub.
Remember, the tub is level.
There is a gap on bottom-left corner. Right side sits on concrete. I shimmed the left side temporarily.
Any advice on a permanent fix for this unevenness that wont make the eventual tile job on the floor look dumb?
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Thanks in advance!

Last edited by ray2047; 10-27-16 at 12:42 AM. Reason: Seperate images.
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Old 10-27-16, 02:03 AM
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I venture to say the tub edge is straighter than the stud line. I would move the studs out to meet the tub edge if possible. When you install your 1/2" cbu, you will bring it just down to the top of the rim and stop. Your tile will jump the gap from the top of the rim to the tub edge and prevent wicking of water.
Old 10-27-16, 04:19 AM
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How thick is the shim at the bottom of the tub?
Old 10-27-16, 06:21 AM
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I agree with Chandler. Move the studs so they are straight. It will also help you when it comes time to sheetrock the ceiling. If you can easily pull the nails without destroying the studs you can go that route but it's faster if you have a Sawzall (reciprocating saw) with a metal blade you can run the blade along the top and bottom and cut the nails. Then move the studs to form a straight wall and re-install them.

As for the uneven floor supporting the tub is the easy part. Finishing the floor, especially where it meets the tub, will be the difficult part. When it's time to permanently install the tub have your shims in place to hold the tub level. Then mix up a half bucket of mortar. Dollop some tall blobs or a long tall line of mortar down the center of the tub area. Then set the tub in place and push down to squish the wet mortar.

After the mortar has hardened you can install a permanent shim under the left side of the apron. I like using cement board, VCT tile or any other material that is hard and not affected by water. The shim can be held in place with construction adhesive and position it so it's flush or very slightly recessed from the tubs front apron. That will allow you to tile or run your flooring right up to the apron. If tiling hopefully your tile is thick enough to conceal the gap. If doing vinyl flooring you can cover the gap by running a length of PVC quarter round or other molding along the bottom edge of the tub skirt.
Old 10-27-16, 04:33 PM
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Thanks Chandler. I hate to see that but I've accepted that's what I'll have to do.

Thanks Marksr- the shimming about 1/2" exactly. I was thinking of selfleveling top coat. I may look more into that.

Pilot Dane- thanks for the info! I'll be marking and movin studs here in a bit.
As for the left floor/apron gap, thinking of self-leveling floor stuff. You used it?
Also, thanks for the tip on mortar bed. I wasn't quite sure if that's something I was needing to do or not. It makes sense and not a ton of extra work to have the additional support.

I'll post back any updates.
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