Should I nail down my 7.5" engineered maple floors or float? I live in Colorado which is very dry in the winter and we use a evaporative water cooler in the summer, so have humidity med-high. One entire side of the installation will transition to carpet if that makes a difference.
Thanks

Wide planks should always be secured to prevent lifting, warping, and general misadventure. Wide laminate with a locking system can be floated, but I definately would not float wide maple.