[Jonscheets]

New to this forum, and it seems very informative. I searched the internet as well as this forum prior to posting, so I hope im not wasting anyones time.

I am going to install a new bathtub and tile the surround next week and was looking for a little guidance. I decided to go with a steel tub instead of fiberglass or cast iron, and I noticed most of the tubs have the self leveling bottom. the instructions for a tub i did before said not to use mortar or a pad because the bottom of the tub is self leveling, so i didn't. needless to say the tub creaks like crazy now. im not sure if you should use mortar with it, or if it was because the floor i put it on didn't have any plywood down for a smooth surface, as it looked like the picture i attached. i plan on installing a plywood flooring on those 2x4's with screws and construction adhesive, sound good?

another question i had is about the lip on the bathtub. do i cover the lip of the tub that gets nailed to the studs with backer board? im sure you do, but wont the backer board bow out a little bit where the lip is? not sure how that would affect the tiles.

my final question (and thank you for bearing with me this far) is, since i am installing the tub in an enclosed area, should i frame in the mortar bed? i have no way of removing the framing once the mortar dries, so i was planning on putting the plastic sheeting down on the plywood without framing and then setting the tub into it. i think if i pour the mortar correctly i shouldn't have to worry about an excess of mortar trying to pour out from below the tub. Thanks again for your time, i appreciate it.

 

[TheEplumber]

I always put mortar under tubs or showers. Lay plastic on your sub floor. I place a few strategically placed "cow pies" of mortar down- thin enough to spread when the tub is placed, but thick enough not to slump away- no form needed
As for the lip- its trial and error- steel tub may not be an issue but you may need to furr the stud faces.
This thread might help

http://www.diychatroom.com/f7/mortar-under-bathtub-necessary-172720/

 

[rehab addict]

Your tub has a top flange, correct? You need to fur out the studs so that the cement board fits over that flange without contorting it.
Keep the cement board about 3/8" off the edge of the tub. Your tile will then start about 1/4" from the edge of the tub, covering the gap between the edge of the tub and concrete board. Caulk that gap and yours good to go.

 

[Ghostmaker]

The tub replacement needs to be mounted to the wall studs with galvanized roofing nails at top of the flat flange. Make sure you read the install instructions. Also it never hurts to level the floor with plywood as required.

 

[oh'mike]

Durrock/backer board----

Install the Durrock so that it stops at the flange,resting on the roofing nails that are holding the tub to the studs----fill the resulting void with thinset before you apply your waterproofing---

Or pack with thinset with as you tile if you are not going to waterproof the board.

Furring out the walls so the board overlaps the flange does not work well---you will have a problem where the backer board meets the drywall if you try that----

 

[Jonscheets]

im guessing the gap created where the tub flange is nailed in will only be about 1/8' off of the stud, right? ive only seen fur strips as small as 1"x2" so there will be a 7/8" gap between the backer board and the tub flange? does that sound right? thanks again for the responses, you guys help is greatly appreciated

 

[TheEplumber]

im guessing the gap created where the tub flange is nailed in will only be about 1/8' off of the stud, right? ive only seen fur strips as small as 1"x2" so there will be a 7/8" gap between the backer board and the tub flange? does that sound right? thanks again for the responses, you guys help is greatly appreciated

You can make fur strips out of plywood or paneling. But listen to oh'mike's advice. He's done this before....

 

[joecaption]

Is there also going to be a shower? If so that old dry wall needs to go.

 

[Jonscheets]

its our only shower in the master bath, so i was going to tear down the drywall about 4ft above the tub flange and install backer board after i put the tub in. i wasnt too sure if oh'mike knew that, which is why i thought the furring made sense since ill be down to the studs on the walls.

i figure it would make sense if i measure the distance the flange and nail sit out from the stud and subtract that from the 1/2" drywall size that i need to match the backer board up to at the top of the shower wall. im guessing that would be 1/2" drywall minus approx 1/4" flange/nail width = 1/4" backer board to be used with 1/4" furring strips. that should match up to the 1/2" drywall that will be above the backer board, and ill tile just over the line so everything looks smooth. hopefully im not complicating things here. Thanks again

 

[jaydevries]

um i would not use 1/4 " on walls with no solid backer check cement board manufactures installation instructions. you will have to much deflection in my opinion

 

[djlandkpl]

Take the drywall down up to the ceiling. As Jay has stated 1/4 is too thin for walls. Fur out the 1/2" backerboard and drywall so they are level.