Homeowners often ask if a vapor barrier is necessary for optimizing attic insulation and protecting their homes from moisture-related damage. The answer, however, isn’t one-size-fits-all.

If flooring is built above areas that could be prone to moisture, think about installing a vapor barrier, otherwise known as a moisture barrier or vapor retarder, to provide extra protection.

“The way to think about vapor pressure deficit is that it is the drying power of the air,” said John Battles, a UC Berkeley forest ecology professor. Readings from Jan. 8 show an extreme ...

“The way to think about vapor pressure deficit is that it is the drying power of the air,” said John Battles, a UC Berkeley forest ecology professor. Readings from Jan. 8 show an extreme ...

As much of Los Angeles smolders, wind warnings return, and fire crews stand guard, scientists say almost unprecedented climatic conditions throughout Southern California led up to the disaster.

“The way to think about vapor pressure deficit is that it is the drying power of the air,” said John Battles, a UC Berkeley forest ecology professor. Readings from Jan. 8 show an extreme ...

“The way to think about vapor pressure deficit is that it is the drying power of the air,” said John Battles, a UC Berkeley forest ecology professor. Readings from Jan. 8 show an extreme deficit ...

As much of Los Angeles smolders, wind warnings return and fire crews stand guard, scientists say almost unprecedented climatic conditions throughout Southern California led up to the disaster.