Steven L. Smith
Bellingham WA Home Inspections
Bad Aim, Goal Not Achieved
In this photo we have the goal, getting warm, moist air out of the attic, and we have the target -- the gable vent. Problem is, we have bad aim. The problem here is that we just have a scatter-shot. Most of that high humidity is going to end up in the attic, not outside. This is just not close enough. Shooting warm moist air in the general direction of the vent does not cut it. Instead, there needs to be a proper termination cut in the roof or the exterior wall and the duct attached to that. Being in an unconditioned space, the duct should also have insulation on it so that warm air passing through in cold weather does not lead to condensation on the duct. Inspectors see attics with serious fungal problems the result of bad aim. This is a favorite poor building practice in older homes in Bellingham and Whatcom County.
Here's a double shot I found recently as a repair from a recent previous home inspection. Check out the photo of the roof deck. I believe that clearly illustrates your point regarding moisture and fungal growth. Like you said these vents should be properly terminated in a vent through the roof or wall.
Comments(6)