I own a house that had 2 sunken rooms in it. I dowled and rebared and filled them in with 5000lb. cement. It's been about 16 months and I'm almost ready for floors. I put down in the livingroom 7/16" OSB with Everlock 208 adhesive and T nailed it every 10 inches. It has held well so far and plan to attach 4 inch engineered wood flooring to it. What is the best method to attach the wood flooring to the OSB? Also the other sunken area is in the kitchen/greatroom. It has developed a CRACK, about 1/4 inch wide by 12' long from one edge to the other. I'm thinking of putting down 1/2 inch Durarock cement board over the existing concrete slab and newly poured sunken room. This will allow me to match the height difference between the kitchen and livingroom as-well-as span the crack in the new concrete. I plan on grinding down the highs and filling in the lows in the kitchen/greatroom before putting down the 1/2 Durarock. Then I 'm putting 12" x 12" tumbled travatine stone tile. My questions are as follows: Is spanning the crack futile? Should I fill the crack with Murcrete first then overlay with Durarock. Should I T nail the Durarock? Please advise me on any steps so that my new floors will last for years.
I don't have the answer to your exact question, because I really didn't understand half of what you said. Sounds like you know quite a bit more than me, so I can just offer you a great place to find knowlegeable people that may be able to help you.