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Discussion Starter #1
in our master bathroom the subfloor (plywood) has been secured to the joists..its solid and im ready to start tiling.. I have Hardibacker underlayment ready to go.. some thinset and some ambition:laughing:

just to put my ducks in a row...

plywood, layer of thinset, hardibacker, screw hardibacker to subfloor, skim joints with tape and thinset...let dry.. thinset, tile, grout, enjoy!

and for the walls in the shower area.. vapor barrier, green board, thinset, hardibacker screwed to studs, thinset, tile, grout, enjoy!

( leave a 1/8 of an inch around the tub to allow for silicone caulking)


:thumbup:

feel free to comment!
 

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in our master bathroom the subfloor (plywood) has been secured to the joists..its solid and im ready to start tiling.. I have Hardibacker underlayment ready to go.. some thinset and some ambition:laughing:

just to put my ducks in a row...

plywood, layer of thinset, hardibacker, screw hardibacker to subfloor, skim joints with tape and thinset...let dry.. thinset, tile, grout, enjoy!

and for the walls in the shower area.. vapor barrier, green board, thinset, hardibacker screwed to studs, thinset, tile, grout, enjoy!

( leave a 1/8 of an inch around the tub to allow for silicone caulking)


:thumbup:

feel free to comment!

Floors---the mesh is usually applied as you tile--if you put it on first and let it dry,you could end up with high spots from the dried thinset.

Walls----The 1/2" backer board is applied directly to the studs---
NO green board behind it----never ever.

----Mike-----
 

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A single layer of plywood is not really up to par for the floor either unless you are using a product like Ditra that allows for a single 3/4 layer of subfloor. Swap the hardibacker for Ditra on the floor.
 

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Discussion Starter #4 (Edited)
Floors---the mesh is usually applied as you tile--if you put it on first and let it dry,you could end up with high spots from the dried thinset.

Walls----The 1/2" backer board is applied directly to the studs---
NO green board behind it----never ever.

----Mike-----

Thanks mike!

A single layer of plywood is not really up to par for the floor either unless you are using a product like Ditra that allows for a single 3/4 layer of subfloor. Swap the hardibacker for Ditra on the floor.
i mis-spoke.. there is 1x12 plank then plywood.. you think thats rigid enough for the Hardi?


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You should be fine with the 1x 12 and 1/2" ply----
 

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Discussion Starter #7
well I let the father in law tackle this.. the floor was a little sloped, I had planned to use floor leveler..he said to lay a heavy bed of thinset toward the wall......well...when he did that then screwed the hardibackerd down what do you think happened?? the thinset found its way in between the screw rows and now i have an "ocean" floor.. waves...

what a mess..




im not going to let him worry about fixing that problem..




anyway... since 2 of the 2 walls of the shower are an outside wall what type of vapor barrier do you guys recommend?
 

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I'd paint the backer board with Redguard or Hydroban then no vapor barrier is needed and the backer is a waterproof surface.
 

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jarheadoo7,

I think you are now on the right course. I just wanted to comment about a few points for the sake of other who may read this and not respond.


A single layer of plywood is not really up to par for the floor either unless you are using a product like Ditra that allows for a single 3/4 layer of subfloor.
Actually that is not correct. While my minimum is 3/4" subfloor, most backer board manufacturers say even 5/8" subfloor is fine. 5/8" scares me, but a single 3/4" is fine. So, you do not need a double layer subfloor, (subfloor + underlayment), unless "the" subfloor is made from planks.

poppameth: Yeah that's fine. I'd personally still use Ditra instead for the crack isolation and slightly less rise in floor height,
I like and use Ditra whenever practical and when the customer will shell out the bucks. But, Ditra is not a crack isolation membrane. It's an "uncoupling" membrane. Best thing since sliced bread! :yes:

I too recommend a surface membrane, plastic on studs is next to worthless.

Jaz
 

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While the backer board manufacturer may say it's fine, the last time I checked with the TCNA it was not. I guess it's all in whose rules you want to go by there, unless they've updated the spec since the last handbook I've got.

As for Ditra, not being a crack isolation membrane, I don't buy that. They don't come right out and say it is, but they do state that by acting as an uncoupling membrane it prevent some of the major causes of tile cracking. Isn't that basically the definition of a crack isolation membrane? Our Schluter rep has even referred to it as such before. Again, maybe it's all in how you look at the product.
 

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Tileguy
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I don't recall at any time the TCNA recommended a double layer subfloor under any CBU. I'd like to see anything different regarding that spec. However, the manufacturer's instructions always trump any recommendations made by the TCNA, always. So, many if not all say a 5/8 single subfloor will work. YIKES. I will stick with the 3/4" spec, I know that will work fine.

Crack isolation membranes allow you to tile over an expansion or control joint, while you pretend it isn't there. With Ditra you still have to honor the expansion joints. It's all in the Ditra Installation Handbook along with lots of other good stuff. http://www.schluter.com/media/DitraHandbook.pdf

Jaz
 

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I'll have to dig through the 2011 TCNA handbook. This thing is massive compared to past releases. There are so many systems covered now that it takes forever to find what you want! So far I'm seeing a lot of reference to 15/32 and 19/32 subfloor in this one. Looks like a few systems are saying one layer of plywood subfloor and one layer of plywood underlayment for the tile. I never tile right over plywood, but it's still allowed according to the rules.

As for expansions joints, maybe I'm just not as familiar with that aspect of it since I've never tried to ignore an expansion joint. Pretty sure I've lost a couple jobs over that too.
 
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