Tub installation Help needed ASAP...

[ifrydr]

Hello -

Thank you in advance for all of the answers I have gotten to date without posting, you are all a wealth of knowledge.

Now for my newest problem. I have a ~120 year old house that I just removed a cast iron tub from. The floor it was on is about 1 1/2 - 1 1/4 below the "new/existing" floor. I realize the new tub can be below the floor by a bit but I was wondering if I could build it up with plywood etc. most of the way and then use some sort of floor leveler etc. to make that area flush with the existing sub floor?

Thanks again.

 

[Jadnashua]

Are you planning on putting in a new tub back into that area?

The least expensive way to raise the floor is a mud bed. Since you have more than the minimum thickness required, it would work.

You'd need to put some felt paper on the floor, then staple some metal lath, then put the mud bed. Mud bed is a mix of sand and portland cement mixed in a 4-5:1 ratio (i.e., mostly sand), then wetted and mixed enough so it will hold together when you grab a fist full. It should not drip water. It's like working with wet beach sand and it will screed and pack to a nice hard, cheap, flat surface. Once you've screeded it flat, pack it down. You could put a board on either side to run your screed over, then remove them after getting that majority section filled and packed, then fill in the holes left by the screed guides.

 

[Sponsor]

 

[Terry]

You can build the floor up, and then set the tub over it.
If you reinstall a cast tub, you only need to worry about supporting the apron and the back ledger.

 

[ifrydr]

Thank you for the help.

I wasn't sure if I needed to be exact or if it is ok to be below the floor "outside" the tub by maybe a 1/4 - 1/2" or so. By the way I am replacing it with an acrylic tub.

Thanks again.

 

[Terry]

Most of the time, when you set a tub, it is lower then the finished floor.
The finished floor then goes up to the tub.

With an acrylic tub, you may need to support the bottom too.
If it's needed, I use a few piles of mortar and let the tub squish it down.

 

[ifrydr]

Ok, couple more questions...

The tub manufacturer does not require the mortar etc. to mount the tub because of the wood core in the bottom I guess. But I was thinking of using spray foam around the bottom to eliminate the hollow sound before I close in the walls. Good idea or not? If so, what kind of foam will not expand too much and cause issues?

This is a 120 year old house and the walls are obviously not square and the floor is not level, so the tub will need to be shimmed. In my last house I used a ledger board and shims. The install manual for this tub says nothing of a ledger board, is that not necessay? And, when and if you use shims under a tub do you attach them to the floor with maybe liquid nails or something else?

Thank you very much.

 

[Terry]

Be careful with foam,
I've had some foam lift things up when they expand.
That's why I like mortar.
I won't uplift a tub or bend it.

Can you post a picture of the tub?

 

[ifrydr]

Unfortunately I am at work, no detailed pictures... It is a low end Aker tub, I haven't looked at it but now that I think about it there may be no "feet" it is just the front and flanges that hold it in place.

 

[Jadnashua]

While manufacturers don't often 'require' mortar, the tub will become very solid only if you install it with some under (unless it is a cast iron, then it is strong enough on its own but still can use some). Not using it means it will deflect and not feel as solid.

 

[ifrydr]

Ok, I lost a day or so in my project now and I will not set the tub until Friday now... So I have a little window to really figure this out and do it right.

Does this sound like the right order?

1. Set the the tub in the alcove and level the tub
2. Drill the holes in the flange etc.
3. Lift the tub out
4. Mix and dump the mortar in
5. "Re-set" the tub and then nail it in lining up the holes etc.

Anybody have any pictures of the mortar process?

Of course I then need to search the archives to make sure I am solid on making my trap and tying into the existing plumbing.

The old house is great and in incredible shape but sometimes I wonder why I sold my nice newly framed/plumbed house, everything was sooo easy to change/redo.........

Thanks again to everyone, you guys are extremely patient and helpful.

 

[Jadnashua]

Put some plastic or roofing felt on the floor to prevent it wicking water out of the mortar mix. Are you sure the instructions say to drill holes in the flange? I think that would be a good way to start a crack. The fasteners are primarily to hold it in place prior to installing the finished wall/tile/panels; not to actually hold it up. Often, you just overlap say the head of a roofing nail onto the edge of the flange. Whatever you use, make sure it won't rust and leave stains.

It's best to use a level as you set the tub. Make sure it is level both side to side and end to end.

 

[JohnfrWhipple]

Scrap the tub and put in a curbless shower

With that much room to work with - why not scrap the tub option and install a nice curbless shower. With that much room to work with have the battle is over.

 

[hj]

tub

quote; With that much room to work with - why not scrap the tub option and install a nice curbless shower

For the same reason people buy Dodge Caravans instead of Hummers. It is WHAT THEY WANT. But, without a ledger board you almost have to drill holes for screws, because the plastic could flex DOWN from under the head of a roofing nail, which would only keep it from pulling out or moving upwards. BOTH of which would be prevented by the drywall and tile.