How level does a bathtub have to be?

Discussion in 'Shower & bathtub Forum & Blog' started by Sparty007, Jan 26, 2009.

  1. Sparty007

    Sparty007 New Member

    Messages:
    33
    I'm installing a Americast "Princeton" bathtub from Lowe's in my 1939 house.

    In attempting to put up my ledger board for my tub today it instructed me to install the board off the floor 13 5/8" on each stud. Once I had done that I threw my 4 foot level on it and my floor must be a little out of wack. I'm about a 1/4" higher in the back (away from the drain) side of the bathtub.

    So what is my best course of action?

    1.) Leave it how it is, and make sure it is level side to side, I'll just have a little more pitch to the tub.

    2.) Raise the front of the tub a bit and lower the back to achieve level.

    3.) Figure out how to level the floor.... will not be easy.


    Thanks in advance
    Ryan

    PS - not sure if it makes any difference but I will be installing ceramic tile floor and surround, with knowledge courtesy of the guys at John Bridge.com!
  2. leejosepho

    leejosepho DIY scratch-pad engineer

    That is probably what I would do since parallel-with-the-floor beats trimming the tub's skirt (and top of the surround to match the same-sloping ceiling line?) or leveling the floor.
  3. krow

    krow Plumber

    Messages:
    906
    Location:
    Ontario, Canada
    If you leave it how it is, if you put tiles on the walls, it may look aquard where the tiles meets the tub. If you choose to place your tile level. The smaller the tile, the more noticable the difference in level.
  4. Sparty007

    Sparty007 New Member

    Messages:
    33
    Could I get by with just doing my option #2? Just raise the front a bit? or would then the tub not be touching the ground in the front, or worse, would that make the tub tilt towards the rest of the bathroom and the water would run out of the tub onto the floor?

    Should I just make the ledger board level, bring the tub in, put it in place and throw a level on it? It's a total gut on the bathroom, so I can move the tub in and outof place with ease.
  5. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,948
    Location:
    New England
    The ledger board is NOT supposed to support the tub - they support the edges in case you do something like sit on the edge and keep it straight. You want the tub level in both directions. The easiest way to do that is to put something like Stuctolite, plaster, or deck mud underneath it and set the tub down in it before it sets up. You can place a layer of plastic both under and over it if you want (under keeps it from drying out too quickly by wicking into the subfloor and above makes it easier to take the tub out eventually since it won't stick to the stuff). This will do two things, fully support the bottom of the tub so it won't deflect and feel much more substantial and last longer, and allow you to get it perfectly level. If you don't have it level, assuming it is also being used as a shower, you'll have leaks or pooling at the low side.
  6. krow

    krow Plumber

    Messages:
    906
    Location:
    Ontario, Canada
    I would choose option #2.

    Achieve a level tub and fill in the gaps with water proof materials (ie: mortar, cement, thin set, etc....)
  7. GabeS

    GabeS Remodel Contractor

    Messages:
    294
    Location:
    Brooklyn NY
    You are installing a new tub. Take my word for it and do whatever it takes to make that tub PERFECTLY level and all sides.

    Jim stated the exact proper way to install it. Make sure there is a bed of material underneath that will form a mold when dry and support the tub nicely.

    Tiling will look unprofessional with an out of level tub. Take your time and get it right no matter how long it takes.

    I use a laser level. When pointed at the back wall the line wraps around the corner and shows also on the side walls (you can also draw level pencil marks on the studs all around at the proper height). This gives you a level line on all three sides. Then after I put the mud on the floor (very generous amount) I just line up the top of the three sides of the tub with the laser line. A few of screws into the studs to hold it in place until the mud drys and you're done. Piece of cake.

    Don't try to work a heavy tub by yourself. :eek::mad:
    Last edited: Jan 28, 2009
  8. Sparty007

    Sparty007 New Member

    Messages:
    33
    Mud under the tub? Even if the manufacturer specifically says "NO material underneath the tub or warrenty is void"?

    I've decided to make the tub level, one way or another. Sadly tub #1 came out of the box with a bent flange and a BIG chip out of the corner. Going back to Lowe's today.....
  9. Terry

    Terry Administrator Staff Member

    Messages:
    14,942
    Location:
    Bothell, Washington
    Find the high point,
    Level to that using a four foot level.

    Shim the apron at the floor so that the tub is stable.

    Most homes that have been around for a while, have sagging floors.
    Leveling and shimming is a must.


  10. Do you think anyone has brought a tub back years later, for a refund?

    No.


    I set all tubs in mortar regardless of what the mfg. specs state. I don't want any weak spots in the underside of that tub and that solid base prevents that.
  11. Redwood

    Redwood Master Plumber

    Messages:
    7,450
    Location:
    Connecticut
    Whoa there on the Mud!

    Americast tubs will delaminate if you put mud under them!
  12. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,948
    Location:
    New England
    If you were sloppy with bedding a tub, it might only be supported by a small point. Then, add water/people, it might be like stepping on a pebble with a bare foot...but, instead of hurting, it could poke a hole in it. That would not be covered by any warranty. Get good coverage with stuff that will smush into full contact and it would be like setting it on a floor, but now it is level instead of out of whack.

    What you don't want is to put stress on the tub. Hanging it from level ledger boards when it is not supported properly underneath or only supporting the bottom partially would do it.
    Last edited: Jan 28, 2009
  13. Terry

    Terry Administrator Staff Member

    Messages:
    14,942
    Location:
    Bothell, Washington
    If you lay a sheet of bisqueen over the mortar, then there is no contact anyway.

    Though I don't put mortar under the Americast either.
  14. GabeS

    GabeS Remodel Contractor

    Messages:
    294
    Location:
    Brooklyn NY


  15. I assume that's plastic sheeting. That's what you're supposed to use for steel tubs or any tub that doesn't recommend mortar base.



    If americast is that heavy/thick plastic tub, I've mortared them before, but with plastic. I believe one I didn't. Whoops! They haven't called me yet, maybe they get a refund? heh

    Anything thin fiberglass.....it's getting mortar base. It's disturbing how many customers have tubs that are spider cracking which is leading to leaks through the floor, which does tons of damage before discovery.
  16. Redwood

    Redwood Master Plumber

    Messages:
    7,450
    Location:
    Connecticut
    Thats what Am. Std. calls it...
    but it all delaminates when you bed it.
  17. Sparty007

    Sparty007 New Member

    Messages:
    33
    So no mud eh?

    It appears that the tub is ONLY supported by the ledger board (I know someone said it isn't supported..... but bear with me) and the outside edge (apron?). Looking at the manual it looks like the bottom of the tub hangs in the air, i.e. doesn't have feet.

    Also, would using low expansion spray foam insulation under the tub after install (filled with water) be of any benefit?
  18. GabeS

    GabeS Remodel Contractor

    Messages:
    294
    Location:
    Brooklyn NY
    I believe the final consensus is definitely mud but with plastic over it to prevent direct contact.

    I don't like the idea of just the ledger board and bottom of apron supporting all the weight. I would feel a LOT better with solid mortar base underneath.

    But I've been called an "overbuilder" many times.

    Bye the way, what happens with steel and fiberglass tubs in structolite? Do they rot? How long does it take? Are we talking 2 years or more like 20 or 30 years before a problem occurs?
  19. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,534
    Location:
    Cave Creek, Arizona
    level

    IF you are saying the tub is 1/4" out of level from one end to the other, what is the problem? The only problem would be a tile line, and since the bottom tile can be cut to fit the tub, AND a 1/4" would NEVER be noticable anyway, just put the tub in. Side note. If the tub does not have feet to sit on the floor, and many do not, the ledger board DOES support the tub. (Most tubs have a tile flange which does an amirable, and adequate, job of stiffening them, and they are used with cast iron tubs which you would NEVER bend by sitting on the edge of it)
  20. Howard Emerson

    Howard Emerson I teach guitar:You call that a job?

    Messages:
    173
    Location:
    Huntington Station, NY
    Yes you can use mud if..................


    But they will not delaminate if he follows the very sage advice that I got from this very forum at some point: Mix your mud, put down 6 mil plastic, pour the mud, put another layer of 6 mil plastic over it, set the tub and level away...............

    No muss, no fuss, no contact with the tub.

    HE
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