rdharbis1

Good morning, thanks all for your interest and suggestions. A couple of questions have been asked:
The state of the floor joists, the kitchen is above my basement and I have access to the joists. These are very stable and in good shape.
The kitchen has two external walls and one load bearing wall. The fourth side is iron railing for the stairs to the basement.

joe, checked on your book and if it was on iBooks I would have bought it this morning. probably will go ahead and order anyway. I would like more info on the Advantech product.
What dimensions does it come in? what dimensions would I use with the 3/8 plywood? I checked some local hardware store websites, and they talk about having it but did not give price or availability, is this a new product?
I kind of like the idea of rebuilding from the floor on up, but only if the results are worth it. If the floor is still an inch higher, nothing gained. Shoring up and preparing existing subfloor is doable... Sorry should never pose a different answer to someone you have asked advice.

isola96

If op puts ply down instead of backer board he has already double his wait limit in this case. joists has 16s on center & has 3/4 down already down which should be opposite from joists now putting 1/2" on top staggered with seams being overlapped at least 2ft from 3/4" ply that's already down to take weekness out of the prior seams.
I'm not a pro floor guy but this method that I've been tought has not failed me yet
I also lay the second layer opposite of the 1st which I have been getting some heat recently on this method being incorrect from the old timer pros.

isola96

Joe will tell you that Advantec is superior to any other ply I haven't used it yet but want to in the worst way I think they come 4 by 8 ft sheets not shore how thick it comes.
If its anyone to really listen to its joe and Nealtw both are extremely knowlagable

nealtw

If you don't have non bearing walls, just go back to Joe's first post and replace it with at least 3/4 adventech, thicker if you have room.

rdharbis1

Thanks for all the inputs from everyone. I realized this job may be too big for me and hired the pros. I also wanted to update the forum on what their methods were.
Remove 3/4 inch plywood (this was my contribution to the job!)
Evaluate and repair planking, squeaks and lose boards.
Lay backerboard 3/8 inch on top of planking
Lay the tile
Work is in progress as I type. I will send finished pics.

isola96

Why did they remove and not replace the 3/4" ply ?!?.. Or drop down to 1/2"?... I don't recall you telling us how thick the planks were any less then 3/4" won't prevent movement.

I take it you did 3/8 instead of 1/4" because you think this will prevent movement?

I don't see that they are using thinset mortar for the backerboard to be placed in?..... This makes me think that they won't tape the seams either
Which will make putting backer board down pointless if avoided both methods of cbu install.