Thank you in advance for advice. I've appreciated this forum over the years.

We're adding on to our house and want the downstairs to have a uniform oak hardwood floor. Unfortunately, the old portion of the house was once all carpeted (even the kitchen!) and thus has particle board over original '70s era plywood. Four years ago I tore out 600 sf of carpet and floated kempas engineered wood, 5/8" thick, over that portion.

Now my question. Can I screw down the kempas planks (they're 6" wide) and use them as a subfloor to attach the new solid oak floor to, or must the kempas come out?

Thank you again for any advice.

That kempas floor was designed and installed as a floating floor, so I would not recommewnd that approach. Also, you are suggesting what we in the trades call a t**d sandwich. This is what yours would be like. Plywood subflooring, then particle board (bad) then floating engineered over foam pad, then a oak floor of some sort. I recommended ripping everything out down to the plywood subfloor and if you need to add anything to the subfloor before installing the oak floors, make it more plywood.

Dear Gary,

Thanks for the advice. Probably not what I wanted to hear, but consistent with all the emphasis on the importance of good substrate I've heard over the years.

I appreciate your taking the time to help.

Sincerely,

David