I am about half way through a major remodeling job. We have resided the house with Hardi-plank (and tar paper – thanks to Breaktime discussions)over the old one-by sheathing, installed a new roof complete with continuous soffit and ridge vents and replaced all the windows with modern casements. We are now priming new drywall (over new fiberglass and cellulose insulation.

We have followed many of Bruce Harley’s tips in his Taunton Press insulation book. One of his repeated points is that insulation (f-glass mostly, cellulose to a lesser extent) does not stop air flow.

Our house is on the top of a hill and exposed to the weather. We are subject to strong winds – especially during winter storms. If I stand in the attic crawl spaces under the roof (outside the insulated envelope) when the wind is blowing, I can feel a breeze of air (presumably) entering the soffit vents and exiting the ridge vent.

Does this breeze reduce my knee wall’s insulation effectiveness? If I stand outside in the wind in a sweater (akin to fiberglass insulation) the wind will cut right through it. Can anything be done short of installing foam board (windproof but not a moisture barrier) on the back of the kneewalls?