Thank you, just for my education why is plywood preferred over the luaun ?

Luan is plywood.

It's just bad oily cheap plywood.

I believe also in the Coretec install instructions it specifies NOT to use luaun as underlayment.

Luaun has voids in it (air bubbles) that can and will collapse. It is never an option when laying a rigid floor. Once the air pockets collapse you are one step closer to full floor failure. And that can happen as soon as you walk on the floor. That's not a great way to start a 25 year relationship with your floor.

There's nothing worse than laying an expensive floor, only to have the cheap, bad/nasty/inappropriate underlay cause it to "die" inside of a few years. And the sad part is, you will probably blame the CoreTec.

Stick with smooth side up plywood. You'll be happy you did.

How do you like your Muir oak flooring by Core Tec? We are thinking of using that same color. Please provide your thoughts on performance and look.

It’s fine, I have a lot of greys and blues and I think it works well with them I’ve had it for2 yrs and can’t think of any issues I worried a lot more in the beginning but it seems pretty tough. I have several cats and entrances directly into house , no mud room so I wanted something easy to cleAn and would withstand some water. Just make sure you use the right cleaning products etc.

Thank you!

We are planning to install COREtec Plus XL on concrete floors. Besides using a 6 mil vapor barrier, will installing an additional underlayment provide better support against vertical denting and/or provide better heat insulation ? This is at ground level, i.e. underneath is the foundation.

We are also planning to install COREtec Plus XL Enhanced as floating floor on previously installed vinyl (glued) flooring in our basement. Anything to consider differently here ? Planning the 6 milm vapor barrier here anyway. Many thanks in advance for any pointers.