A few years ago, some folks had me come to their home to try to evaluate an odd ventilation issue they were having after their new roof was installed. They were suddenly getting condensation on the inside of their home’s exterior walls. This condensation was worst behind couches and other items that were located up against the walls. The condensation was causing mildew.
When I walked into their home, I felt air rushing in when the door was opened. I asked them if anything was changed when the new roof was installed. They could not think of anything. Then I asked if I could look into their attic. As soon as the entrance to the attic was opened, a great amount of air could be felt and even heard rushing into the attic space.
After some more questions, I learned that a ridge vent had been installed with the new roof. Yet their attic had no intake (soffit) vents. This was an older home and what was happening was that the draw created by the ridge vent was bringing cold and even moisture in through the home’s deteriorated brick walls. This was then condensing in areas where there was not good air movement inside their home, such as behind furniture.
In this case, there was opportunity for soffit vents to be added to the attic. This would then provide airflow to the ridge vent so it could function as required and ventilate the attic rather than pull air from the home’s living space.
In other cases, though, if there is no soffit overhang or way to add intake vents to the attic, adding a ridge vent can be a very bad idea by creating a situation similar to what these homeowners were experiencing, but yet not have any easy remedy.
So, I am a firm believer in attic ventilation but, are there times when it is not a good idea? Absolutely.
Contact me anytime with your roofing or ventilation questions. firstname.lastname@example.org