Messy Tile Floor repair

"Someone" put thinset mortar and tile on top of a 1/2" planked wooded floor that has an age of approx 50 years.
At one point in time, the toilet must have overflowed and caused the tile floor to have a distinct "dip".
I have cut-out the bad section....all of the wood was rotted. However, the original subfloor was intact and indeed covered with vinyl.
Now I have an irregular shaped opening of about 2 square feet that needs to be filled in before I can lay new tile. It's approx 2" deep from the top of the existing tile.
Instead of going thru the lengthy and tedious process of cutting a piece of cement board to fit the opening, I am considering pouring concrete instead.
I called the Quikcrete people and they recommended their FastSet Self Leveling Floor Resurfacer poured in 2 stages due to the thickness.
I'd like some feedback on this idea. To me, this seems like the best approach.

 

Welcome to the forums! Can you post a picture or two so we can see what you see? Thanks.http://www.doityourself.com/forum/el...your-post.html

 

I'll wait on the pictures to say more but you mention vinyl and that tells me there might be quite a bit which needs to come up before you tile.

 

My bad on the vinyl. It's actually like a tar paper that can be easily removed. Underneath is likely plywood.

See attached pictures.

 

The damage likely extends further back to the toilet area. Tap on the tiles with the handle of the screwdriver, if it sounds hollow, you have additional issues.

Considering it was installed wrong in the first place, time to consider a complete redo.

Just being honest, floating a repair that big will have some challenges. For self leveling compound, you will need wire lath, self leveling primer, tar paper and the self leveling compound itself. Read the back as each brand has a different thickness that can be poured. Make sure your brand will accommodate your needs.

 

Elementary question. Do you have replacement tiles to begin with?? I agree with Z that a total tear out would be in order.

 

Yes, I do have the replacement tiles...and No, the damage does not extend into the toilet.
Why do I need the tar paper ? Why do I need the wire ?

Quikrete tech support told me to do two separate layers....and that I did not need the wire lath.
Total thickness required: 1 1/4".
I'm going with QUIKRETE® Self-Leveling Floor Resurfacer....which is good for 5/8"....so I'll first trowel in a 5/8" layer of their high-strength cement.
I've always done well with their products.
I plan to line the bed with thick foil first.

 

Over plywood you need wire lath, mechanically fastened to the subfloor with a uncoupling membrane underneath.

Keep in mind that Quickrete is mainly a concrete product and not really a solution for an interior tile installation. From the Quickrete website the following is the direction - Provide Self-Leveling Portland Cement and Underlayment for placement over existing concrete substrate. If you want to learn about self leveling compound, research products fron Mapei and Custom Building Products. This companies deal with tile and repairs for interior applications with tile as the end product. Yes, wire lath, uncoupling membrane and primer are standard protocol.

 

Thanks much Czizzi for your advice.
However, there is a new, high-tech solution to my problem that only requires primer:
http://www.ardexamericas.com/en-us/P...ckerBoard.aspx
Luckily, I have a local Ardex dealer...sadly, he does not stock this product.
However, I believe Ardex has a manufacturing facility in my state, so I might be able to get it quickly.
Note: the liquid backer board goes up to exactly my 1 1/4" depth requirements....how lucky is that ?