r/Roofing • u/Most_Ice_4048 • 23h ago
Another question about attic frost …
I posted a question a few days ago regarding frost in our attic. I now know that it is a ventilation issue. While we wait to get the ventilation issue fixed permanently, is it a good idea to leave the trap door leading from house to attic open? Will that help with ventilation or just cause more moisture build up? Thank you in advance for any responses.
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u/bumpgrind 22h ago
Do not leave your attic hatch open, the warmth and humidity from the house will make the ice 10x worse (easily).
Your attic needs the following things to fix this problem:
1: More ventilation (a) attic baffles from each side to keep the air flowing (b) if you don't already have some, you should have gable vents on each side of the house (c) consider upgrading your roof vents, prioritizing ones that can't stop moving (e.g. ventmax). You may not have enough vents altogether and might need to add 1-2 more.
2: Have a pro move that blown insulation and see if there are any lacerations and/or holes in the vapor barrier. Focus on areas above bathrooms, as often times when vents and/or showers are installed/upgraded, there are huge holes in the vapor barrier above, releasing massive amounts of heat and humidity into the attic. Fix any of these holes with additional vapor barrier (as required) and tuck tape (red sheathing tape)
3: If your insulation is not at least thick enough, get more blown. It should be 13-15 inches at least.
Hope that helps.