From what I read non-vented attics are more common in the north, but in the south the attics must be vented and you can’t make a vented attic into a non-vented one.
In our area (the south) people try plugging up the vents thinking they’ll save money. Then mold starts growing and they spend a fortune getting rid of it.
Roofers know better; they’re putting in ridge vents all the time now.
“From what I read non-vented attics are more common in the north, but in the south the attics must be vented and you can’t make a vented attic into a non-vented one.”
Actually, here in Texas, I visited a new house that had a sealed attic, sealed with spray-on foam. If the builder is smart, he’ll get out of the country once he’s secured his enough money.
“””In our area (the south) people try plugging up the vents thinking they’ll save money. Then mold starts growing and they spend a fortune getting rid of it.”””
Mold is not the only problem.
In Florida, when the outside temperature is 90 degrees, the temperature in my VENTED attic will be 125 degrees. Without attic vents the attic temps would be even worse and my air conditioning bill would be much higher.
There some science to ventilation. It needs to allow the air to follow a path. Just venting isn’t helpful as the air just turbulates in the attic. Having a specific path with entry vents like soffit vents and roof exit vents works great to keep the attic space properly vented.
My home uses soffit vents and turbine vents on the roof. They are ugly but are by far the most efficient.