Steven writes from Rutland, Vermont: "Our house only has 1 gable vent on the west side of the house. An addition was put on the east side years ago but no gable vent was put in. To further complicate the matter a cupola vent with a weathervane was put atop the addition. I do not know if it is just for decoration or if it really is acting as an attic vent because the attic part of the addition is blocked off with plywood, but I do see a cut-out nearer to the ridge in the form of a triangle. Also, the house has perfect soffit vents that I see from the outside but the insulation in the attic is blocking the flow from the inside. I plan on putting those things you put to keep the insulation from blocking the soffit vents. Would this be enough or do you think I need a gable vent on the east side? Also, is there any way of checking to see if the cupola vent is functional not just decorative? We also have a ridge vent the whole length of the house. Also, is more insulation needed other than the one layer that is there?"

Answer: Gable vents work best when used to provide cross ventilation. So a gable vent on the east end would generally be the way to go. But soffit vents are also involved although blocked at this time. Soffit vents work in conjunction with ridge vents which you do not have. So what you have is a mixed ventilation system. Soffit vents are for intake and that air is most likely exiting the one gable vent. It is hard to tell if the cupola provides and ventilation without actually getting up and looking at it, either from underneath in the attic or above from the roof. They are typically decorative. If you are using our FIBERGLAS™ insulation it will be necessary to layer the material to achieve higher R-values. For example, to achieve R-49 in an attic floor, which is recommended by the U.S. Department of Energy for many parts of the country, you could layer R-30 and R-19 insulation.