Continue CBU discussion

[deananddebbie]

First of all, this is a great forum. I have learned all lot reading all the info. I have built my house myself (except foundation and drywall) to this point. It would have been nice to find a site like this for other projects.
I wanted more clarification, or at least your opinion on my specific situation in regards to installing concrete board underlayment for the floor. I have engineered joists on 16 inch centers spanning 12 feet. I top of these I have glued and nailed 1-1/8th inch tongue and groove sturdi-floor as the subfloor. In one of the discussions it was said that the thinset under the CBU is the provide break away if the joists move and to level the floor. Isn't the point of using engeneered joists to minimize the movement and I can't see how my floor could get any more level? Also, by nailing or screwing the CBU to the subfloor, if the joists move, the subfloor would move, thus the CBU will move any way. Hopefully someone can explain all this to me.

[John Bridge]

Welcome Dean and Debbie,

The CBUs are laid in a bed of thin set and then nailed to the plywood panels only and not into the joists (not deliberately, anyway). The idea is that the CBU will remain stable if the plywood shifts or shrinks.

I tile floors over 1-1/8 Sturd-I-Floor using Schluter Ditra. I recommend it instead of backer board. It's only and eighth of an inch thick, and it takes about 1/4 the time to install.

http://www.schluter.com/english/prod...601-index.html

[deananddebbie]

Thanks for the quick reply. I went to the Ditra website and looked at the installation specs. I guess my main heartburn over any of these possibilities is that they all require me to mortar the backing material (Ditra or CBU) to my subfloor. What if a few years down the road I want a different flooring material? How can I remove this stuff if it is mortared to my subfloor? Wouldn't I end up damaging my subfloor? Or am I worrying about nothing?

[tileguytodd]

Hi dean&deb,If you are installing a Ceramic tile floor, why would you want to change your flooring on a few years?A tile floor is designed to last the life of the structure done right.However, there are ways to prepare your floor for another type of flooring after the fact.Remove the ceramic tile with a demolition hammer,same with the Ditra(it will shear away from the Advantech leaving the thinset stuck to the advantech.You would then lean the area with a vaacuum and Tack down some 2.5 wire lathe,prime the floor with a special primer and pour a Self leveling Cement over the works.There, you are now prepared to put down vinyl, wood or another ceramic floor and you didnt have to tear up your subfloor.Pretty cool eh

[John Bridge]

And let me just add . . .

I don't know of any way to install a tile floor without gluing something down.

[Scooter]

Ditto on the inch and an eight t&g. That stuff is great, and whenever I can convince the homeowner to use, we do. Super strong; easy to lay, tough as nails. I don't do the Ditra thing yet, because, well, its hard to teach old dogs new tricks.