Building up bathroom floor to make the best carpet transition

[highup]

Carpet is in a hallway and the bath underlayment has been removed to make way for ceramic tile. I am trying to figure out how to build the bathroom floor up to get the best carpet to tile transition height.

Bathroom floor is currently 1/2 inch below the hallway, and I am wondering what combo of materials would make the thinnest allowable bas to set the tile on.Here's what we are starting with:
2X6 subfloor on 16" centers. I think customer was going to install 1/2 inch cement board or Hardi directly on the 2X6's
I know it's not enough structurally.

Will 1/2" plywood, or 5/8" plywood work over the 2X6's and then add a membrane over that?

 

[Ernesto]

I think customer was going to install 1/2 inch cement board or Hardi directly on the 2X6's
I know it's not enough structurally.

CME is not structural at all. I'm certain the tile guru's at that other place already told you that.

Plywood is best, but you'll need more than 1/2 inch, more like two layers of half inch, CME or Ditra. Then there's that Tavi stuff.

 

[BudCline]

Most building codes I am aware of require a minimum of 5/8" thick subfloor. No warranties will be honored over 2X6 floor joists that I can think of. That size floor joist isn't really suitable for anything except an outdoor deck, certainly not a tile installation.

You CAN NOT use CBU attached directly to floor joists, that isn't even funny. CBU's offer absolutely NO structural value what-so-ever.

DITRA is typically warranted over 5/8" plywood subfloor but the 2X6 joists will likely demolish any warranty that would be there.

The Tavy product leaves a lot to be desired, you never ever hear anyone talking about using the Tavy material.

How about a nice vinyl tile for this project? That would work just fine.

NOT ALL STRUCTURES ARE SUITABLE FOR CERAMIC TILE​

 

[havasu]

I myself would find a way to sister the joists with 2 x 8's, then plywood.

 

[Ernesto]

The Tavy product leaves a lot to be desired, you never ever hear anyone talking about using the Tavy material.

Yes true that, but maybe because you never hear about anything unless it is a POS. Besides, I'd like to watch Highup work with it, that might be fun. Just giving options for the build up. Hey, this would be a great area for him to learn muddin. Then he could get it butt perfect.

 

[highup]

Yes true that, but maybe because you never hear about anything unless it is a POS. Besides, I'd like to watch Highup work with it, that might be fun. Just giving options for the build up. Hey, this would be a great area for him to learn muddin. Then he could get it butt perfect.

Hope Bud wasn't thinkin' that I thought CBU that was good over 2X6's...... Hey, I don't do tile, but I'd charm ay prospective tile setter to make a different choice.

Went t take a look and it looks like T&G 2X6's fr a sub-floor. The contractor figures adding 1/2 inch plywood, then the tile guy will add CBU or whatever to get the height to where it needs to be.
I think he's be better off adding 3/4 inch plywood over the 2X6's, then Ditra and forgetting about CBU........... How thick is Ditra? 1/8" ?

Would this system work? ...........2X6's + 3/4" + ditra

 

[BudCline]

I think he's be better off adding 3/4 inch plywood over the 2X6's, then Ditra and forgetting about CBU........... How thick is Ditra? 1/8" ?

The above method would be my choice. And yes...DITRA is 1/8" but it is also available in 5/16".

With joists of only 2X6 you need all the help you can get. Adding 3/4" plywood would be a big plus.

 

[highup]

The above method would be my choice. And yes...DITRA is 1/8" but it is also available in 5/16".

With joists of only 2X6 you need all the help you can get. Adding 3/4" plywood would be a big plus.

I think it's gonna end up 1/2 inch plywood with some type of cement board over it. Contractor and tile setter are doing what seems best.
As a side note, the 2X6 material is probably 40 year old doug fir, back when they harvested trees with tight grain.
It's not new construction, so any settling has occurred, and neither of the home owners are heavy.
Hey, I'm just tuckin in the carpet edge.

I appreciate all the feedback, and decisions have been made. It'll be fine.

 

[BudCline]

It's not new construction, so any settling has occurred,

That's okay...there are many millions of people that don't understand the dynamics of building construction and use their lack of knowledge to justify a means to an end.

 

[Isola96]

I think it's gonna end up 1/2 inch plywood with some type of cement board over it. Contractor and tile setter are doing what seems best.
As a side note, the 2X6 material is probably 40 year old doug fir, back when they harvested trees with tight grain.
It's not new construction, so any settling has occurred, and neither of the home owners are heavy.
Hey, I'm just tuckin in the carpet edge.

I appreciate all the feedback, and decisions have been made. It'll be fine.

Sorry but not understanding why they needed to cheep out on the ply in order for the hight fight?..
Could at least sistered and cat the 2x6 joists then your 1/2" would have a fighting chance.
What size cement board?.... 1/4" is best for floors.

3/4" and ditra mat is the way you should have gone and even that is bare bones over 2x6.

 

[highup]

That's okay...there are many millions of people that don't understand the dynamics of building construction and use their lack of knowledge to justify a means to an end.

Sorry but not understanding why they needed to cheep out on the ply in order for the hight fight?..
Could at least sistered and cat the 2x6 joists then your 1/2" would have a fighting chance.
What size cement board?.... 1/4" is best for floors.

3/4" and ditra mat is the way you should have gone and even that is bare bones over 2x6.

Do that many jobs fail?
Nobody here or anywhere I know of will tear down to the joists for new plywood buildup to the 'tile mfg specs"
It's nice to use those specs, but this is a bathroom, not a large living room, dining room or grand entry.
Walking into the doorway of this bathroom, you proceed past the bath tub/shower and you are walking 6 inches to the right of a floor joist. You are almost walking on the floor joist from the doorway to the wall at the far end, 8 feet away.
Is the tile going to pop off or crumble apart? I have worked in a few thousand homes over the years and tile falling off the floor does not happen. ...........and nobody here seems to follow the recommended procedures. They should....... but it just doesn't happen often.
Heck, I worked for a guy that pre fit the tile in his kitchen and with the tile was layed out bare on top of the plywood for a few days, ......it didn't crack even without thinset under em......and he's 275# or more. He walked on it.. I saw him.
I do understand "ideal", but this is reality............ the homeowner is not ripping out the 40 year old floor joists to sister them, nor ripping out the 2X6's to install two layers of 3/4" or thicker plywood.
If it was my own home, I would do over kill. Overkill is my middle name. My only job here will be tucking carpet to the tile once it's installed. I was just asking so I could pass on
some advice if it looked warranted.

5 or 6 years ago, a tile installer added backer board over the floor in a double wide modular home............... it looks great. Why?
We know the sub floor in those places are not plywood. We know the sub floor is not anywhere near 1 3/4" thick.............. so why hasn't this job totally failed by now? Why is the grout not cracking apart? Why no broken or loose tiles?
Not sayin' it's right............... Not even close. If I was a tile installer, I sure wouldn't have done it that way........... but why hasn't it failed? According to specs, it should be a total failure by now.
We are talkin a large kitchen and dining room area, an entryway, two hallways and bathroom, all connected.

 

[Isola96]

@ highup Totally get what your saying. I was taught that you need at least 1" of plywood to tile on most of the time this will make the hight in most bathrooms exceed the fact that cbu board will make the floor to high, so using the right plywood would make it possible to tile right over plywood. Now that being said its very very frown upon to do that method but never failed for me nor the people who taught me this way.
I'm not a engineer but the last thing you want is deflection... Movement in the subfloor or your grout will crack, tile won't pop off so building the joists up by sisters and cats will only help, 1/2" is flimsy and cbu or ditra holds no strength just a filler to bond the tile.

 

[highup]

@ highup Totally get what your saying. I was taught that you need at least 1" of plywood to tile on most of the time this will make the hight in most bathrooms exceed the fact that cbu board will make the floor to high, so using the right plywood would make it possible to tile right over plywood. Now that being said its very very frown upon to do that method but never failed for me nor the people who taught me this way.
I'm not a engineer but the last thing you want is deflection... Movement in the subfloor or your grout will crack, tile won't pop off so building the joists up by sisters and cats will only help, 1/2" is flimsy and cbu or ditra holds no strength just a filler to bond the tile.

If it was my own job, or my own bathroom, I'd probably go over the 2X6's with 3/4 then Ditra. Contractor and tile setter made the decision to use 1/2" then cement board. If it has issues, its their problem.
I can see the possibility of having problems if it was a 14 by 20 dining room where the possibility of having many people sitting or standing side by side would cause more deflection.