Home Depot just substituted our order of 1000 sq ft of db4looring with a product called Floor Muffler and told my sub there is no difference. I looked up the MSDS and find that 100 sq ft roll of db4looring weighs 75 lbs while 100 sq ft of Floor Muffler weighs under 4 lbs. Yes, less than 4 lbs. I did a double take too.

I understand the db4looring is high mass vinyl, the Muffler is polypropylene foam. My understanding also is that sound proofing requires (1) density and (2) isolation. Yet Home Depot parrots Floor Muffler’s claim of an STC of 69. To get STC 69, — respectively for floors or walls – one must offset studs or joists, disconnect the studs and rafters from the drywall and subfloor with channels and buffers, double the thickness of the ply and drywall (increase mass), and fill the cavity or bay with insulation. Db 4looring makes no such claims and instead says that the use of its product will up the STC rating by 10 to 12 points from whatever sound rating is inherent to the basic assembly.

The floors are to be floating, HDF cored, engineered hardwood. Should we return the Floor Muffler and insist on the db 4looring.