Q: I had our attic spray-foamed in 2010. Our HVAC contractor recently did a semiannual service. The technician came down from the attic, where he was checking the air handler, and he was wringing wet with sweat.
Another technician said we needed an energy consultant to check the spray-foam job since leaks in the foam were likely allowing hot, humid air into the attic. The consultant suggested removing all the batt insulation in the ceiling and redoing the spray foam to totally encapsulate the attic.
Is this good advice?
A: We asked Harris Gross of Engineers for Home Inspection in Cherry Hill, Pa., and Joe Ponessa of Rutgers Cooperative Extension for their takes.
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Gross says: “Make sure all the vents are sealed. If open vents are found, sealing them should resolve the matter. If not, the second step would be to verify that the spray foam insulation was properly installed.
He said that installing batt insulation matters only if you have supply and return vents. It doesn’t make a difference one way or the other if there are no vents.
“If no air vents are added, the attic will be a little hotter or cooler than the outside air temperature, and that will transmit to an extent down into the current living space,” he said. “So if no air-supply vents are added, I would suggest keeping the batt insulation. I would not redo the spray foam unless it was improperly installed.”
Ponessa says: “This sounds like the beginning of what is called a ‘non-ventilated’ or ‘conditioned’ attic, defined as being part of the heated and cooled space of the building.
“This is generally a good thing: It reduces summer ceiling temperatures in the floors below (more so than attic ventilation), reduces summertime moisture loading in the attic, and provides a much better environment for any heating, air conditioning and ductwork equipment located there.”