Published on July 27th, 2015 | by Henri0
Ridge vents work only with soffit venting
Q. The day after every snowstorm, icicles and ice dams form on my roof. The attic floor is very well insulated, but there are no soffits because there is no roof overhang. There is only one attic vent on the side of the house. Would a ridge vent relieve my ice problem? Any help you can give would be appreciated.
A. Ridge vents are not effective without equivalent, or greater, soffit venting. The ice dams and icicles you experience, in spite of having a very well insulated attic floor, tell you that there is considerable heat loss into the attic through some paths.
Sometimes, the only way to find these anomalies is through infrared thermography and a blow-door test. Call your power company and ask if they perform these tests or can refer you to someone who does. The cost may be significant, but think of the money you will save on energy costs – and in the prevention of costly damages to your house. There may also be a program in your state where the utilities perform these tests at no cost.
If your roof will need replacing in the near future, it is possible to have soffit venting installed despite having no overhangs. For instance, Air Vent, Inc. (www.airvent.com) manufactures a Vented Drip Edge for just such situations. It requires minor alterations to the roof sheathing.
Other manufacturers also offer such systems. DCI Products (www.dciproducts.com) offer the Smart Vent, which can also be installed where roofs do not have overhangs.
Check with your local building supply stores for availability or order online. Then a ridge vent will make sense. If you decide to go that route, close the gable vent as it will interfere negatively with the new system.
But the energy tests I suggest may help determine whether or not you need more ventilation. If the anomalies are easily fixed with closed-cell foam, you may not need any ventilation, although it is generally considered advisable.by