New drop in whirlpool CRACKING!!!!

Discussion in 'Shower & Bathtub Forum & Blog' started by Don, Mar 29, 2005.

  1. Don

    Don New Member

    Messages:
    27
    Location:
    New York
    [​IMG]
    K-1257
    Mariposaâ„¢ 6' Bath Whirlpool
    I bought a ( Lowe's display ) Kohler Mariposa 6ft X 3ft whirlpool tub..never used..it had a couple small corner cracks at the top lip..I set it in a bed of motar mix with 3/8 inch plywood shims on top of the Hardibacker wrapped tub surround...a friend helping me sat on the side of the tub..in the middle..later I noticed a crack at that location..can one NEVER sit on the edge of a tub like this with out getting more cracks?..this will be used mainly as a shower too..it seems the flex at the top will forever open the caulk seal .,and cause endless water problems..and this new bathroom is upstairs!!!...is this model of a horribly thin gage construction?..is it known world wide that you never, ever bear any weight on the top of fiberglass tubs?..I haven't installed tile at the tub area yet, but worry that the finished project will still create serious headaches due to the apparent light gage flex of this tub on the + or - 1/8 inch caulk seal...I'm doing this project by the BOOK...is this a common nail-biting concern for others?..any thoughts?..Thanks -Don
    Last edited by a moderator: Apr 9, 2005
  2. Clayton

    Clayton Plumber

    Messages:
    124
    drop in whirlpool

    If the unit is setting on top of 3/8 shims and someone sits on the edge without continuous support under it, yes it can crack. If the shims where providing continuous support then I would guess the unit is too thin and you should notify Kohler to get repair or replacement.

    Some of your description confuses me. Such as this is a drop-in unit being used for a shower and you installed it with 3/8 shims on top of the surround.

    Is this unit being installed against 3 walls (alcove installation) or does it have a deck around it? The "surround" is IMO considered the walls around the tub, so I assume you ment you installed it on top of 3/8" shims on a deck. I take it the 3/8" shims are for tile so the whirlpool needs to be within 1/16" from the finished deck for the caulk joint. If this is installed in a deck, how are you going to use the shower? A wrap around shower curtain? Anyway, do not put any pressure on the outside edge of the unit until you have the finished surface under it within 1/16". Good you set the unit in a mortar bed for better support.
    Last edited: Mar 29, 2005
  3. Don

    Don New Member

    Messages:
    27
    Location:
    New York
    It's sitting on a 2 X 6 deck with 3 walls around it..yeah, the shims are for the tile and 1/8th inch caulk..I've had alot of people tell me that it's really not a big problem using one of these as a shower..yeah..you're right..I guess this isn't really done huh?..I've already imagined a wrap around shower curtain..either that or a radical modification such as sealing the deck/tub edge with a heavy filling of construction adhesive and building up the deck with more Hardibacker in a slight tubward slope and bull nosing tile on the top surround of the fiberglass tub itself..is that madness?..might be the only answer...Don
  4. Clayton

    Clayton Plumber

    Messages:
    124
    Whirlpool shower

    Well, using a whirlpool as a shower isn't a big problem if its installed correctly. From your discription, I am imagining that the tub is installed on a deck away from all three walls. So there will be some tile deck surface all the way around the edge of the tub that the shower can spray on but has no way back into the tub. First of all, the Mariposa is available with a tile flange on 3 sides for an alcove installation. Even if the tile flange wasn't available you would still want the tub against all three walls and then the backer board and tile on the walls could overlap the edge of the tub on these three sides. You could still have the deck on the long exposed side. Then a regular shower curtain could be used or with this paticular model you could even install a glass shower door enclosure since the edge of the tub is flat and straight.
    If you do not want the walls to be against the edge of the tub with the wall tile coming directly down onto the edge of the tub then you should do as you already described. Building up the deck area around the tub and installing the tile over the top edge of the tub so it looks like an undermount installation. I've installed 4 whirlpools several years ago that this was done to. I do not know of any problems that has occured with this type of installation.
  5. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,139
    Location:
    New England
    Until all sides are firmly supported, you should never put any weight on the edges of that kind of tub.
  6. concrete anyone??

    did you install this unit in a base of concrete???

    it isnt sitting on shims or just hanging in mid air??

    I have a 36 x 6 foot clarke wp tub that I did the same thing with in my own home and it works real fine....I framed under the tub with 2x4s then on top I framed inwards over the lip approx 2 inches in and sealed under the 2x4 with silicone to seal it real good. Then the water proof drywall with silicone under thelip then the tile.

    if you framed it in all around the three sides and along the front too, so the total lip is sitting on the 2x4s it should not have any stress on it..

    but it also depends on how you set it down to the floor.

    you got to figure 1 person and 60 gallons of water , thats a lot of weight,

    then if you and your wife jump in there and get frisky, thats a lot more weight and stress to the fiberglass.


    Now , if your wife is anywhere near the size of mine, , then thats a WHOLE LOT OF WEIGHT to factor into the stress on the fiberglass.
    (I used about 4 80lb bags of sand mix under my unit) :D :rolleyes:

    no cracks yet
    Last edited: Mar 31, 2005
  7. Don

    Don New Member

    Messages:
    27
    Location:
    New York
    Yes..as it is now..I set the (drop in) tub in sand mix...in a three wall alcove...on a 2 x 6 inch deck...just one side open...it's all plummed...all the framing and deck is covered with 1/2 inch thick HardiBacker...the shims were used to allow room for tile to be installed on top of the deck and uder the lip of the tub and also 1/8 caulk.In other words, I set the tub in the sand mix and worked the tub down in it until the top edge of the tub was resting on the 3/8th inch plywood shims..I hope that's enough information..just looking for advice on how finish this out so it won't be a water nightmare when I shower..such as building up the HardiBacker board on the deck surface to be flush with the top of the fiberglass tub deck itself ? and then bullnosing tile on top of the tub itself...maybe even before all that..filling the gap between the deck and the tub with construction adhesive so it won't flex..love advice from anyone that can make sense of this..Thanks!! ..Don..P.S. does my fix mentioned above sound ok?
  8. daveydo

    daveydo New Member

    Messages:
    36
    I just finished installation of a Maax tub of similiar construction. In order to tile under all 5 sides I framed and shimmed as you descibed. After setting it in a bed of mortar. I removed the shims and later tiled. Maax instructions said that the tub must be supported on the bottom and under the rim. However, they make no mention of the mortar bed. If the tub is supported as I've described it should be ok.

    As for the cracks, send some pics. The guys on this site will be better able to help if they can see the problem . a picture is worth a thousand words.
  9. Don

    Don New Member

    Messages:
    27
    Location:
    New York
    As for the cracks..there are two on the top corners and one in the middle...all on the verticle lip edge...it was a Lowe's display model and got moved around alot apparently..sorry I don't have a pic...The install instructions say..DO NOT support tub on the rim...only support on the bottom..and I used the motar mix option to do this...and they say use the shims to allow 1/4 inch tile to fit under the lip on the surround deck and 1/8th inch of caulk...when I sat the tub in mortar and worked it down I wound up with some areas less that an 1/8th inch for caulk and other areas about 1/4 inch...the thing is , with the top edge of the tub flexing the way it does when you bear weight on the edge..I can imagine this breaking a caulk seal every time..every time!!...and if I shower..which is what i always prefer..then water will always trickle inside the tub surround...It ain't cast iron..maybe other fiberglass tubs are built much more solid and ridged than this Kohler Mariposa..Even if it was as solid as cast iron, I still think water from a shower would RIVER around the deck onto the floor..Unless someone thinks my plan is crazy..or has a tried and true better idea..I'm going to load a ton of construction adhesive under and on the side of the tub lip as I build up Hardibacker to slope in flush with the top of the tub and then tile around for an under mount look to the tub..I may be the first person on earth to ever do this..I'll post the results of my project and even pics for the good of humanity...Don
  10. minor repairs

    just repiar the cracks and be done with it.

    its probably no big deal anyway.

    if you want to see a picture of how I shimmed out my tub,

    go to this site. Check out the pics at the bottom of the page

    and you will get an idea of really the only way to be dead sure that

    your tile job wont "screw you over" 5 years form now


    I went way overboard, but I aint doing this again for at least 40 years

    and I probably will be dead by then. If I am lucky.


    if you look at the one pic where the tub is sitting against the concrete side wall shims,
    I stood a a 2x4 sideeways on the lip of the tub to extend the drywall out way over the edje of the unit to be sure that the water will never "screw me over" and ever get behind the unit.

    I also took silicone and glued the 2x4 to the unit to really seal it good.

    so the drywall and tiel is actually sitting in about 2 inches over the outside lip of the unit.

    this baby isnt comming out anytime soon.


    http://weilhammerplumbing.com/services/
    Last edited: Apr 4, 2005
  11. Don

    Don New Member

    Messages:
    27
    Location:
    New York
    Thanks Mark..I'll check out your pics after the Tarheels win tonight...I really miss titled my original post...I'm not worried about the cracks..I'm really not..it's the flimsy flex that bothers me..flex that can and certainly will open the caulk seal around the top lip of the tub...and the idea of tiling the the deck the way it is...a future 4" wide river of misery..."again"...these are my primary concerns...Don
  12. Don

    Don New Member

    Messages:
    27
    Location:
    New York
    I see what you did and understand..I must be failing to express myself clearly..again,I know I could have installed the tub differently to begin with or even bought another type of tub all together....but as it is , I have already installed the tub in a three wall alcove...open on one side...It's already in...it's set in mortar mix...on a 2x6 surround deck that will allow a 4 inch wide area for tile all around the tub..well..except for the wall spout side , that's about 2 inches wide because I'd need a foot long spout so it's more narrow there.....and I've finished all the plumbing.....anyway,It is from this point where I need to proceed...so if you have any ideas based on taking it from where I'm at now with this project I'd love to here it..If all I was going to do was lay there cozy and soak with a Harliquen romance novel ..there would'nt be a problem..ok..that (would) be a problem...but i want to use the shower too!!..Does the fix I detailed above (if you scroll up) sound like a viable solution in this case?....I absolutley should have installed mine just like the one you did..but it's too late for that..so..what would you do from this point?...no sledge hammers please!! I just finished the granite floor...Thanks Don
    Last edited: Apr 4, 2005
  13. a picture is worth thousands

    get a pic of what sort of problem you got

    and post it on this site...
  14. Don

    Don New Member

    Messages:
    27
    Location:
    New York
    Sorry I don't have a pic..It's just a tub surrounded by three walls..sitting on a 2x6 deck wall...just trying to get the ok for my plan to eliminate water going under the tub and flowing around the surround deck on the floor..It's frustrating that no one can visualize that...I must have a very rare, never seen before installation...I'll just go ahead with my plan..thanks anyway...Don
  15. John Aull

    John Aull New Member

    Messages:
    6
    Don -

    Can he really be called a friend if he cracked your tub??!!

    Still your neighbor :D
  16. Don

    Don New Member

    Messages:
    27
    Location:
    New York
    Well neighbor, I must have been on crack to allow the bargin price of the tub to put me in a position of doing these radical modifications...Don
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