# Installing Maax Advanta "New Town" bath tub, leveling and support issues



## rodney23 (Oct 1, 2010)

Hey all,

I'm working to install a tub, a Maax Advanta "New Town" 60 x 30 alcove tub. 

The tub has three supports, the front edge and two 4x4 posts about 4.5" tall. Those 4x4 posts then support a 1/2" sheet of plywood which acts as a platform the tub portion of the tub rests on. And lastly there's the 1x3 support under the rim attached to the studs around the 3 sides along the wall.

So, my friend and I get the new tub in the alcove, but we're having a heck of a time getting it level. There seems to be a good hump in the floor causing it to rock. If we get it level and shim under the front edge (something I know we're not supposed to do... but it not permanent... yet), there's a good 3/4" gap between the tub and the floor. It gets smaller and smaller from left to right.

I'm not sure what my options are here. Using a self-leveling cement to try and make up the max 3/4" gap sounds like a lot of cement. We're contemplating using (and you can see what we're going for in the pics) wide shims to fill the gap and keep the tub level while providing a near 100% contact for the tub edge to minimize stress points when there's water in the tub. The idea being we'll trim up the shims to the tub edge and then when the tile goes down, we'll push mortar into any gaps to secure the shims (they'll be nailed too... the mortar would just be extra). Do you guys have any other ideas. 

Also... the instructions mention using a mortar bed (even if we didn't have these leveling issues)... but because of just the 2, 4x4 supports... I'm not sure what the mortar would accomplish except to act as a bit of glue. Since the tub is basically on a platform... I'm not sure it would affect the sound or thermal properties any. 

Thanks for the help!

~Rodney


----------



## rodney23 (Oct 1, 2010)

*pics*

Here are the images I mentioned.


----------



## TheEplumber (Jul 20, 2010)

rodney23,
There are some threads on here that address similar problems. i suggest doing a search using the search feature at the top. Some guys got pretty creative.


----------



## LIHR (Jan 18, 2011)

Sounds like you didn't level out your sub-floor and now you are scrambling because of that. Tubs should only require a little tweaking to get dialed in. 

I read the instructions for that tub and the use of mortar may be the way to go. Otherwise you may need to remove the tub and eliminate that "hump" in the sub-floor.


----------



## Alan (Apr 12, 2006)

Mortar would do the trick, but what are you going to do with that gap when you're done?


----------



## rodney23 (Oct 1, 2010)

Hmm...

Well.. a search of the forums doesn't get me too much (at least searching for bathtub and level). Most of what I found talked about using mortar under the supports to get it dialed in perfect and provide a solid base. However, as I mentioned... there are only 2, 4x4 posts and the front skirt for support. Couple that with the fact that the tub is rocking from front left to back right (as you look at the front skirt), and I don't think mortar under the supports in the back is going to cut it while providing a level floor that supports the front skirt. The mortar bed method appears to be for tubs that have an almost solid base against the floor the size of the tub and for making minor tweaks to achieve level... not the issue I'm having.

I pulled the tub and the shims out tonight and sanded down one of the high spots along the floor under the front skirt by the front right (I also found a corner of the sub-floor that wasn't secured in the same area... the screw missed the joist). It helped a little... but as you can see with the tub leveled front to back and side to side and what feels like good solid contact of the two posts supporting the back side (against the long alcove wall)... there's still a gap, about 5/8" at the front left.

I'm just confused about what to do... it would be one thing if it was off front to back or side to side... but the fact that it rocks on a diagonal makes it hard to know what to do to get it to sit correctly without shimming the front skirt. Any help you guys can give is greatly appreciated!


----------



## rodney23 (Oct 1, 2010)

LIHR said:


> Sounds like you didn't level out your sub-floor and now you are scrambling because of that. Tubs should only require a little tweaking to get dialed in.
> 
> I read the instructions for that tub and the use of mortar may be the way to go. Otherwise you may need to remove the tub and eliminate that "hump" in the sub-floor.


LIHR,

Thanks for taking a look... btw... the instructions cover their full range of tubs (generic install instructions), and so the use of mortar under the two 4x4 posts in my mind wouldn't have too much effect. By two posts, I mean they used two small 4x4 posts roughly 4 inches high to support a platform the tub sits on... meaning there is quite a bit of air between the tub bottom and the sub-floor the posts rest on.

Admittedly I did not check for level prior to getting the tub up. However, there was a tub-surround in there previously along with a tile floor and so all I did was remove and replace the sub-floor as needed. I guess the surround was probably never level, although we didn't notice.


----------

