How to Improve Ventilation With Fiberglass Insulation

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  • Transcript

    LESLIE: Nick in Texas has a question about ventilation with fiberglass insulation. You’ve got The Money Pit. What can we do for you today?

    NICK: I want to add some blown-in insulation into my attic.

    TOM: OK.

    NICK: The house only has gable vents on three ends. Do I need to block the soffit area when I’m blowing in insulation?

    TOM: Yeah. Do you have soffit vents now, Nick?

    NICK: There are no soffit vents. Only the gable vents.

    TOM: So, you really – yeah, you really should open up the soffits to improve ventilation with fiberglass insulation. You should have continuous soffit ventilation. Then you would put insulation baffles in there, which basically holds the blown-in insulation back so that air can get into the soffits and ride up under the roof sheathing. And then you might also consider adding a ridge vent at the peak. The more ventilation, the better when you’re dealing with fiberglass insulation.

    NICK: OK. So even (audio gap) soffit vents, I still need to leave that area for air to flow.

    TOM: Yeah. And do you know what an insulation baffle is? It’s like a foam channel or a cardboard channel that fits in between the roof rafters. And it basically just makes sure the air can get over any insulation that’s piled up where the roof and the soffit comes together, because it gets kind of narrow down in that deep corner. So this keeps it open so that airflow can get in there for ventilation with fiberglass insulation.

    NICK: OK.

    TOM: And this way, it’ll – as it moves into the soffit, it’s going to push up under the roof sheathing and exit at the ridge.

    NICK: That makes sense.

    TOM: Alright. Good luck with that project. Thanks so much for calling the show.

    NICK: Alright. Thank you.

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