Danny and Joe welcome callers’ questions each week on the Today’s Homeowner Radio Show.
Here’s a question from our Dec. 22 broadcast:
Matt in Maine says, “During this recent cold snap, I decided to peek up into the attic just to check early in the morning before work. To my amazement, I saw frost on the nails poking through the plywood sheathing and a little on the sheathing as well.
“I read that to remedy this problem you first try to seal any air leaks (bypasses) from the flow below. I went ahead and [applied] expanded foam near the plumbing vents, duct tables around the bathroom exhaust, and caulked around electrical boxes.
“My home does not have a poly vapor barrier and we have about 8 to 12 inches of blown-in fiberglass insulation distributed evenly throughout. Only on cold (less than 15 degrees Fahrenheit), still, nights is when the frost happens.
Based on this, I believe I need to now improve ventilation within the attic space because it appears that the warm, humid air is getting trapped and not moving out of the attic on still calm nights. The current ventilation is a ridge vent and gable vents (no soffit vents).
“My question is, would adding soffit vents help eliminate or significantly reduce frost in my attic. There are no other obvious sources of moisture other than the ones I listed above and sealed.”
Listen to the embedded audio clip above for the answer!
Read the blog from the Dec. 22 show and listen to the full broadcast here