We're looking into finally replacing our old washer & dryer and are looking into the front loading ones. Dh had read somewhere that if you install a front loading washer on a floor that is not concrete (ie, on a joist floor) that it will rock and shake. For those of you who have one, what has your experience been? Our laundry room is in the first floor mud room, off of the garage, and since there is a basement below, it wouldn't be on a concrete floor.