Go Back  DoItYourself.com Community Forums > Interior Improvement Center > Designing Kitchens and Bathrooms
Reload this Page >

New cast iron bathtub and bathroom floor installations

New cast iron bathtub and bathroom floor installations


  #1  
Old 03-03-03, 10:51 AM
sktracy
Visiting Guest
Posts: n/a
Question New cast iron bathtub and bathroom floor installations

Hello,

I'm in the process of installing a new Kohler cast iron tub (with apron) and have a few questions:

1. Does the cast iron tub need any additional support underneath? The current floor is 3/4" particle board (I think) over the subfloor (either 1/2" or 3/4")

2. I read somewhere that I can use metal shims to level the tub. What are metal shims and where can I get them?

3. This tub weighs over 300lbs, so once it's in the right spot, I don't want to have to move it again. Any tips on how to make sure this happens? What if the tub is not level once placed? How do I lift it to add/remove shims? (NOTE: there will only be access to the front side of the tub once it is installed because the tub is the same length as the framed opening)

Also, a question regarding flooring:
4. Can I install a tile floor directly over the flooring mentioned above (3/4" particle board over plywood subfloor)? I removed the laminate and the particle flooring underneath is in good shape without much apparent glue residue. My original plan was to pull up the particle board and replace it with Wonderboard, but if I don't have to, that would be great.

Thanks,

Steve
 
  #2  
Old 03-03-03, 12:05 PM
Brewbeer
Visiting Guest
Posts: n/a
Re: 4.

You CAN install tile directly on the wood floor, but it probably won't stay stuck down very long. Use the cement backer board, it comes in 1/4 inch thickness, shouldn't add too much height to the floor
 
  #3  
Old 03-05-03, 10:33 AM
Doug Aleshire's Avatar
Member
Join Date: Feb 2002
Location: United States
Posts: 4,455
Upvotes: 0
Received 0 Upvotes on 0 Posts
sktracy,

Ok, you asked, here's some answers...

1. The Kohler cast iron tub doesn't require additional support like mortar or jouint compound as I have posted such procedures before due to it's WEIGHT!
 
  #4  
Old 03-05-03, 11:33 AM
Doug Aleshire's Avatar
Member
Join Date: Feb 2002
Location: United States
Posts: 4,455
Upvotes: 0
Received 0 Upvotes on 0 Posts
ktracy,

Sorry, hit the wrong button...let's do this again...

1. The Kohler cast iron tub doesn't require additional support like mortar or joint compound as I have posted such procedures before due to it's WEIGHT and material makeup! This can sit directly on 3/4" subfloor as long as we are dealing with 16" O.C. support joists. I am wondering though about what you mentioned .. "3/4" particle board underlayment over the 3/4" subfloor" ...UNDER the tub area? Is this correct?

The reason I ask is that a tub should be sitting on the subfloor...NOT the underlayment. Not knowing what tub you are getting, like the Mendota or similar I did take a look at the link below;

http://www.us.kohler.com/onlinecatalog/pdf/100206_2.pdf

If you noticed page 2 - Fig #2 it shows a "Subfloor" and the "1/2". I decided to call Kohler and confirm what I suspected. You need to have the new tub sitting in a recess so that the NEW underlayment (1/2" Minimum) will "butt" against the front apron. Obviously this ruins your options of your #4 question.

2. Metal shims are available if required and can be acquired through a plumbing supply store but most plumbers use...you'll love this...copper tubing - smashed down to form a shim and surprisingly... it works!

3. Once the tub is in place is a bad time to move it. You should take your time and using a level, check the area under the tub to ensure that all is level. It's better to make adjustments here and now than when the tub is in position. If for any reason, the tub is not sitting level, a "ledger" could be applied to the back wall/end walls to make it so. This is done by not using shims and that the front apron/skirt is sitting directly on the SUBFLOOR, not underlayment.

4. Unfortuantely the 3/4" particle board underlayment is not recommended in a "wet" area. Application of a ceramic tile floor will require a more substantial underlayment, like brewbeer mentioned a cement backer underlayment which come in sizes of 5/16", 1/2" or 5/8" thick. Only the 5/16" cannot be applied to walls but it is ok for floor underlayments as the other two are. This must be applied not only with screws but it must be applied with a V-notched trowel using thin set mortar or an organic adhesive. This is to ensure that nothing moves between the 2 materials and ensure that your new tiles and grout stay sound forever.

I want to stress a couple of things here so you don't end up with problems.

First...the particle board could stay but really shouldn't. Particle board and water don't mix and this stuff swells. Any water infiltration onto this or into it will cause problems. I fear the issue surrounding the tub installation will require it's removal anyway.
With this said, I would choose 5/8" cement board, then your tile which would place everything back to almost original height. The 5/8" would be butted against the tub apron.

Second...the total finished floor height will be critical if we are talking about the gaps between door bottom and floor so depending on what you use, you can determine the actual size of cement board needed along with your tile adhesive and tile to virtually keep the new floor height at or near what you have without worrying about other issues...cutting doors down, relocating wood base moldings (if applicable), etc..

Hope this helps!
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: