Notching studs instead of shimming for tub install

[roundrightfarm]

I'm installing a tub in a 3 wall alcove which will be tiled. The manufacturer says to shim under the concrete board so it overlaps the tub flange smoothly. This seems like a good bit of shimming, especially since one wall is full bathroom length. This wall also has a window which comes very close to the edge of the shower/tub tile. I'm worried that if I shim the entire wall, my window extension jambs will not quite fit. If I only shim around the tub, I see how the drywall could transition back to no shims smoothly enough, but I still might have an extension jamb problem at the side near the tub.

I could easily notch each stud on two walls and fit the tub flange flush with the stud edge. This would mean I would have to shim even more the one wall on the side with the spout and valve as well as shim a little less behind the flange on this wall. In this case, it looks like I may also need to shim behind the valve so it sticks out a little more to connect with the handle.

Has anyone done this before? Are there other problems I'm not thinking about. Thanks

 

[Terry]

That small amount of shaving the studs should be fine. I've never don that, well maybe one just to fit an overly large tub into a standard space. Someone at the factory didn't trim the tub to a standard size.

 

[Sponsor]

 

[Jadnashua]

A 5' tub is often, not a full 5', and sliding it into an alcove can be a pain if it is tight against all three walls. Can you do it? Maybe, but keep in mind things do move with humidity and temperature changes. You don't want things really tight. Plus, often, it's a good idea to bed the tub in some mortar to stabilize it and keep the bottom from deflecting. This also lets you level it properly. If you've notched your studs, that means you can't drop it down, and must slide it in (if that's even possible with other stuff in the room).

Keep in mind also that it may be acceptable to just stop the cbu slightly above the top of the tiling flange. As long as more than 1/2 of the tile will be supported on the cbu, it will work. You must have a moisture barrier behind the cbu, lapping over the tiling flange.

While a bit more money, but superior in my opinion, instead of a water resistant tub/shower wall, you could consider buying KerdiBoard panels. You can notch the bottom edge easily to fit over the flange, and when done, you'd have a totally waterproof installation rather than a water resistant one.