A builder near the Seattle sent me this picture. Strange. I would have thought that the studs would have condensation on them before the cavities would. I get that the exterior wall is warmer under the eave, so no condensation. They claim that the walls had blown insulation. I’m going next week to do a thermal scan. What do you think? Failed insulation or failed vaper barrier? I live on the eastern side of the state. No condensation her:) Be kind!
Sorry. As a new user I can’t upload an attachment
Lori, send them to me at tom@glazehi.com and I’ll try to download then for you.
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Lori, do you know if the blown insulation is fiberglass, loose fill cellulose or dense pack cellulose , or is it actually spray apply cellulose which is often confused with blown insulation because it is applied with the same machine ( with an extra attachment at the nozzle)
Each of these insulation types behave differently with regards to r-value and air blockage.
The wall should not have a vapor barrier but it should have one or more layers of vapor retarder. These might seem like minor details but if you can verify these specific details it will affect the answer since these materials perform differently.
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Here is what I wrote to the builder.
I think I figured out the answer to the condensation on the siding. Is the condensation just on the sun side (south or west) of the building? Cold moist air hitting the side of the building that is warmed by the sun. Notice no condensation under the eaves. The sun is not warming that area. Also notice that both buildings are a dark color. The reason for the lack of condensation on the studs is that the studs are a colder surface then the cavity. Therefore not hitting the dew point. Of course it could be that the wall has poor insulation, but I doubt it. Next time I’m in your area I’ll bring my thermal gun.
Lori Sanders