Ever notice how This Old House and many publications are geared toward the Northeast? Well, here is an excellent PDF presentation by Building Science corporation on insulating in hot/humid climates like the South: ‘…Too much ventilation may even cause
damage by cooling off the top of the insulation. We have taken
cases where excess ventilation will cool the top surface of the
insulating material�So too much ventilation may be dangerous
just as well as too little…’ They also have Joe’s Top Ten List of dumb things to do in the South for buildings.