Installing cast iron tub

Discussion in 'Shower & Bathtub Forum & Blog' started by Leo427, Oct 31, 2004.

  1. Leo427

    Leo427 New Member

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    Oct 31, 2004
    I am in the process of having a cast iron tub installed. Currently, the tub is resting on a ledger board attached to the wall. There are shims under one end of the apron to keep the tub from rocking due to a gap. All four feet of the tub are in the air. The directions from Kohler state that the feet should be supported with metal shims for support with no mention of a ledger board. Should I shim the feet in addition to the ledger board or leave it as is with the feet unsupported? I feel that it wouldn't hurt to shim the feet also, but I do not want to look for trouble. :confused:
     
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    The tub must be supported on its feet. You risk cracking the tub or tearing the ledger board out when you fill it with water and put a person or two in it. Ensure that the top rim is level, also. Make sure you use something substantial under the feet. The tub probably weighs ~300#, put 40 gallons of water in it adds 320#, and then say a 250# person - 870#, give or take.
     
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  4. hj

    hj Moderator & Master Plumber Staff Member

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    shims

    My first question would be why the legs are in the air. Normally, if the tub is installed on a level floor the legs all set on the floor and the ledger board is just a formality.
     
  5. LonnythePlumber

    LonnythePlumber Plumber, Contractor, Attorney

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    No ledger board?

    No ledger board for a cast iron tub? Has anyone else heard of this or is not installing ledger boards?
     
  6. Leo427

    Leo427 New Member

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    Oct 31, 2004
    I was basing that on the installation manual from Kohler. Please see Figure 6 on Page 5 by clicking on the link. I says that all four feet must rest on the floor and does not mention a ledger board. Thanks for your reply. http://www.us.kohler.com/onlinecatalog/pdf/100206_2.pdf
     
  7. LonnythePlumber

    LonnythePlumber Plumber, Contractor, Attorney

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    Yes, No Ledger

    Certainly you are right. There is no ledger board mentioned. I haven't read installation instructions on a cast iron tub in decades. I guess I should.
     
  8. hj

    hj Moderator & Master Plumber Staff Member

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    ledger board

    I only use one on a wood floor, and that is just to be sure that even if the tub settles into the flooring, the edge of the tub will stay locked to the bottom of the wall finish.
     
  9. Terry

    Terry Administrator Staff Member

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    I've seen the legs on cast iron tubs sinking into the plywood before. I install using a ledger board to prevent that. And for the same reason that hj does.
     
  10. lanachurner

    lanachurner Member

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    I never install a ledger board.
    What I do is buy 4 blank metal covers for an electrical light box and set them under the feet/legs.
    They are cheap and heavy enough to prevent the legs from sinking into the sub floor. Then you can use shims on top of them if needed.
    Remember to set the tub so it tilts toward the back wall about 1/8". This will prevent spillage over the sides and rotting out the wood at the corners.
     
  11. hj

    hj Moderator & Master Plumber Staff Member

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    quote; Remember to set the tub so it tilts toward the back wall about 1/8".

    HOW do you do this if the feet are sitting on your metal box covers and the feet are designed to keep the tub level with the front apron ON THE FLOOR?
     
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  12. lanachurner

    lanachurner Member

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    Use 3 covers under the outside feet and 1 under the inside ones. They are about 1/16" thick so the back slope works out just about right.
    If you buy the round ones for a light box they're only about $.40 apiece.
    Cheap enough...
    If you're really on a budget, buy those new fangled wedges they use for shimming doors on the outside ones - between the foot and the plate. They are made out of a very dense plastic/composite material and do not compress under the weight of the tub.
     
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