So I have written previously about my disaster installation of almost 2000 sq feet of Cosmopolitan Vanier engineered santos mahogany 5" width over 1 1/4 OSB which widely delaminated and checked, and cupped. After multiple inspections, there was zero evidence for any high moisture issues with subfloor, only normal low humidity in Nevada . So now I am getting bids to tear up the existing flooring and replace it. Have two competing bids. Both have recommended engineered hardwood flooring again. The choices are Armstrong 3/8" 4 7/8" width engineered prefinished Santos Mahogany glued down over subfloor (after tear out and repair, and leveling). The other involves glue down and nailing of some type of 1/4" material recommended by installer on top of repaired, smoothed and leveled subfloor, and then glue Mullican 1/2" 5" wide engineered santos mahogany over that.

Of course I will insure good acclimation, and that all appropriate measurements are taken and documented prior to installation, (moisture readings are taken of flooring with no more than 2% difference (for 5" wide planks) between subfloor and flooring). I looked at the installation and warranty booklet, and quite frankly, if anything, the warranty coverage for these American products are no better( 35-55% humidity requirement) than the Chinese product that delaminated, so I am still nervous that the same thing could happen again.

Any recommendations regarding Armstrong vs. Mullican, and thoughts about using a 1/4 layer on top of the subfloor and putting the flooring on top of that.

More than likely if your buying an exotic, even from an American company it could be made in China. And not made to U.S. standards, you know what I'm talking about.

If your not going to humidify your home with an exotic hardwood then you should save your money and get tile or something.

There is quite a few American manufacturers that warranty the construction for a lifetime and then some even specify hpva standards.