I think the key word is "floating". This isn't a floating floor, it's a naildown. I don't believe it's going to be nearly as effective in a naildown situation, as most of the noise that is "muffled" in a floating situation is from the fact that there isn't good solid contact with the subflooring, as in nailed down. WHen there is good solid contact with a subfloor, the majority of the noise produced is from the reflective (rather than absorbtive) nature of the hardwood surface itself. Sound just echoes more into the air from a hardwood floor than it does from a sound absorbtive carpet floor. No amount of underlayment is going to alter the nature of the sound echo produced because the flooring is a hard floor product and not a textile based flooring product. It may be possible that installing a manufacture approved for naildown installation sound barrier can help with some of the percussive sound transmission from floor to floor, but it'll never be as quiet downstairs as if carpet on padding was the second floor material. And, you'll still get sound echoes upstairs that travel through the walls and open areas, simply because the wood surface reflects sound. You can't alter the basic nature of a hardwood floor. You can use rugs and additional soft furnishings to moderate the sound absorbtive properties and mitigate some of that reflectivity, but you'd have to practically cover all of the rooms wall to wall with rugs to make it be as quiet as carpet could be.

Gregmills, thank you for replying to my post. In 2009, I had several installers take moisture readings and my floor was dry. BUT since 2009, I had the water damage from the water heater on 3-20-13 which damaged the 5" wide BR-111 Brazilian Cherry engineered wood floors which have not been removed and are over the Floor Muffler Ultra pad that they were floated on. I had to buy area rugs as the planks had cracked and lifted. I was waiting to have the insurance claim settled first before removing the floors. My little 6 lb Maltese got her foot caught costing me over $300 with the vet bill, X-rays and pain medicine. Thankfully nothing was broken when she was running and got her foot caught in the floor and was whimpering and carrying on. That is why I bought the inexpensive temporary small area rugs to cover many of the damaged areas until the insurance company settled with me. I had chosen to install the same Brazilian Cherry Wood but now sold directly by Triangulo to stores rather than first sold to BR-111. I just want to change my width to 3.25" from 5". I would prefer a floating floor again as it felt like a solid wood floor but was not so hard on my feet. The store had bought a large lot of 3" Solid Indusparquet Brazilian Cherry Hardwood so can give me a very good price on installing the solid wood by gluing it down using SIKA 2. I did look this product up and they are saying 3/4" solid hardwood can be glued directly to the concrete since it has a moisture barrier and good holding power but flexible. I did call the manufacture of this wood today and Indusparquet will not warranty the solid wood unless it is nailed to plywood floors. I have get to go to the store to discuss the estimate he prepared for me but I am feeling I need to tell him that I really prefer the 3.25" engineered wood downstairs and upstairs. In the summer time, the air conditioner keeps the humidity level down and the house is maintained at 36 - 40% humidity. In the winter time, the dry air is a problem with my forced hot air heat. I used humidifiers downstairs in the day time in my home office and upstairs at night. I have never had a problem with the 5" engineered wood floors until the water damage so I feel I am OK with the engineered wood floors. But when I go upstairs at night, it is very dry and I have to run the humidifiers on a long time to make my bedroom humid enough so I do not get nose bleeds. This is what I am afraid of with the solid wood. I am also afraid of the install failing downstairs where the concrete floor is not flat/level. I filled the large cracks I found when the carpet was removed in 2009 before the installer arrived to install the floor. I will not use him again as he told me to use 2 less boxes so I changed my order and we ran out of wood and he never came back to finish the job when the wood arrived. I want someone to do the full job and charge me extra for moving the heavy cabinets. I have bought so many stackable crates since I will empty them. I have called moving companies to get prices and in case a store does not want to move the cabinets into my garage themselves and to put them back on the floors.

I am double posting this (from Design Dilemma) because I hope for professional flooring advice and also suggestions from people who've done this. We live in the Pacific Northwest (rainy winters and dry summers). Our house is 13 years old with ¾” OSB subfloors on joists 16” on center. We want to remove the carpeting in the dining room, living room and hallway (above grade) and downstairs hallway (on grade), and replace the carpeting with wood flooring. We also want to keep the height difference between these rooms and the adjoining tiled kitchen to a minimum. Because of this requirement, I am leaning towards 1/2" engineered wood rather than solid 3/4" wood. The new flooring would be professionally installed. Am I correct to say that OSB does not hold nails/staples as well as plywood for nail-down installation, nor does it provide a suitable surface for glue-down engineered wood flooring installation? Would glue-down installation avoid the squeeky-squeeks that might result from a nail-down installation? We have heard that installers recommend having an underlayment put down over the OSB to provide a better adhesive surface for engineered wood flooring and we would have that done. I don't think a floating floor would be an option because of the upstairs room size (50' x 15') and high ceilings (possibly too noisy). For glue-down engineered wood flooring, what underlayment would be best between the OSB subfloor and the engineered wood floor? How thick would it need to be? Thank you Mary

Cork, as I mentioned in the earlier thread, does not need to be glued. It can be floated. That means it just sits there. Doing nothing. Minding it's own business. An engineered hardwood that is DESIGNED to be floated (must state on the installation instructions) can then be floated over top. The tongue/groove is glued (a line of glue is applied to the tongue/groove) and then pushed together. You wipe up any excess glue and then move on to the next plank. Some blue tape is then used to hold the planks together while the glue cures. It takes about a day. Once you the glue is cured, you have a fully functional floating engineered hardwood floor. Done. It is MUCH CHEAPER and much faster (almost half) than adding new sheathing and then gluing/stapling the hardwood. Whether or not you can float/staple will be clearly notated on the installation instructions.