Solid Hardwood, Engineered and Laminate Flooring - Sound barrier underlay for Hardwood floors?

Would placing an underlay they use for laminate flooring under the hardwood floor have any benefit ?

I am wondering if it would help reduce sound or have any benifit in muffling sounds between upstairs and downstairs.

I'm definitely no expert, but I would guess that the underlay would have minimal effects on sounds between upstairs and downstairs. Maybe some, but not alot. Probably insulation "in between the two" would have more effect of muffling the sound.

The underlay, from what I hear and have gathered, will have more impact upstairs, because it will help absorb the sounds of walking on the new flooring.

Maybe that'll help, and maybe someone with more experience will reply to you.

Good luck.

I'm also inexperienced with full hardwoods, but I would be concerned that a pad under the wood could cause the boards to move or "work" and develop squeaks as they rub together because they won't be on a solid surface. Hopefully a "no kidding" hardwood guy will answer this one.

Engineered wood floor with cushion attached offers some sound deadening qualities. Carpet offers the best sound deadening. Cushion beneath solid 3/4" hardwood is not recommended. It is a nail-down product installed over 15# minimum roofing felt. Runners in hallways and area rugs on the second floor can help with sound deadening on solid hardwood.