Unvented Attic Problems

Areas with hot summers and cold winters can suffer the effects of both.

Unvented attic problems.

The energy savings touted by unvented attics can be as high as 20. When it s hot outside the sun beating down on the roof can increase the temperature in the attic. Here is a sampling. Heat and moisture buildup in an attic cause predictable but different problems in hot and cold climates.

Lots of gba readers have posted reports of this type of problem. An unvented attic is conditioned space and won t be subject to the extremes of temperature common to vented attics. Too many people believe the importance of roof ventilation is to increase energy. However if moisture is able to enter the unvented attic space it may lead to roofing panel issues.

Unvented conditioned attics were quite rare before the 1980s. Unvented attics do not experience such problems. Roof vents are for warmer climates. The intent of this brief is to provide code related information about controlling moisture in unvented attics by installing a vapor diffusion port vent that would convey water vapor from an unvented attic to the outside when air permeable insulation materials are installed and can be verified as being in compliance with the related codes and standards for residential construction.

Heat is thus less likely to escape into an unvented attic from hvac equipment and if it does it will remain within the conditioned space. Just like properly sizing your furnace and air conditioning unit you want precisely. Attic ventilation myths that are off the charts 1.