Minimum thickness of subfloor for hardwood in basement

Our cement basement is very dry due to the part of the world we're in and we have a whole bunch of relatively cheap pre-finished maple hardwood 2 1/4" x 3/4" that matches our main floor. So we've decided that we're going to use that as the flooring in the basement. I realize this isn't recommended and that the final floor will not be insurable but, ignoring all that, what would be the minimum thickness of subfloor that I could get away with? Also, what would you recommend for the best materials to use and method of anchoring the hardwood?

Thanks,

 

Welcome to the forums! Well, figure you will be driving 2" cleats at a 45 degree angle through the tongues which set about 1/4" below the surface of the flooring, that will leave about 1 1/2" of cleat or staple sticking below. Using the pythagorean theorem......just kidding.

As long as you are aware you will need to fasten the plywood to the concrete in some manner and have that figured out, you may get by with a 3/4" Advantech and another 1/2" of plywood on top of that fastened with seams offset from each other. Now you will have to deal with your door jambs if you have any, as they will be 2" higher once the floor is in place.