Monday, Feb. 7, 2005: Joe's Advice - Don't Do Stupid Things
Unfortunately, many of the standard building practices in Florida and other southern states fall into the stupid category, Lstiburek said.
He pointed out that there are two kinds of stucco: stucco that leaks and stucco that will leak. If people are going to build homes with stucco finishes, he said, it is not a good idea to use foil-back vapor barriers in the wall. It doesn't allow moisture to drain outside the building, where you want it to go.
"If you also use a vinyl wall covering inside," he said, "that's stupid squared. And that's the majority of hotels in Florida."
It's critical that walls have a bond break such as would be created with a tar paper barrier, to allow drainage to occur.
Roof venting is also silly in climates like Florida's, Lstiburek said, because they only tend to draw more moisture in. "You don't need to vent to prevent ice dams in Florida," he stated.
Why do homes built in southern states have northern design features such as roof vents? "Because the South lost the Civil War," Lstiburek proposed. "There is no reason based in physics."