Thanks for your input. That was my concern as well. Is that with solid wood, most recommend putting in plywood which would defeat the purpose. I guess I can select a low VOC plywood, but then why not just select a low VOC engineered floor. This is why I’m leaning towards engineered.
I’ve seen people nail solid wood flooring directly onto sleeper frames with a thin moisture barrier underneath. Insulation is added to prevent the hollow sound. In fact, some gym floors are designed this way. But it suffers the height problem you mentioned. It appears to be the only no glue method I’ve seen.
