Exisiting roof with no overhang. New siding. Any way to air seal at the wall-to-roof interface?
MikeonLI
| Posted in General Questions on
Re-siding a house now and have an existing roof. Most of the house has no overhangs. Using a self adhered membrane on the sheathing.
is there any way to connect the wall to roof interface at the rake edge?
On the gable end, for example, the wall sheathing goes up and terminates right under the roof sheathing. If the roof and siding were done at the same time, it would be easy to bring the self adhered wrb over the wall sheathing and onto the roof sheathing. But I don’t have that option
could I cut the sheathing just short and tape the top of the wall sheathing to the roof rafter on the gable end? Any other ideas welcome
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Replies
Are you aiming for airtightness, watertightness or something else? Are you pulling off any rake trim? Do you have drip edges at the rakes? Is your sheathing plywood?
Airtightness and watertightness. There’s an existing roof and I am changing the sheathing and siding. I put a picture below. I am worried about air getting between the top of the wall and the framing and getting into the living space. Where there’s attic like in my picture I can seal the top plate from the inside. But I have a lot of rake area where there’s no attic but cathedral ceiling and can’t seal from the inside bc it’s finished space
I have plywood sheathing and will be putting in drip edge flashing on the rakes after I remove the rake trim. I will have to nail it from the side rather from above bc the roof is intact
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Can you post a photo from th exterior so we can better understand the situation you have and give a better answer?
I got a good answer for this question from
My contractor. Thank you for asking!
Here’s a pic
That looks like a vented attic. If that is the case sealing to the roof isn't needed as you want air flow in the attic. What you want is to seal the sheathing to the ceiling air barrier. With existing structures, this is typically done by spray foaming the top plate in the attic but could also be done with caulk or brush on mastic.
Akos
In that area I agree that the top plate can be sealed from the attic side which I did. But I have a lot of similar rake area with no attic but cathedral ceiling. So I can’t seal that from the inside
Without an airtight attachment between roof and wall, air can get between the top of the wall sheathing and the framing and get into the living space. Or can get from the living space under the sheetrock and in the cavity, exiting the gap where the framing meets the wall sheathing. It’s a vulnerable spot and I have a lot of area like that without attic
In a new Roof situation I could lap the roofing membrane over the gap and onto the wall sheathing to create and airtight seal. But I can’t do that with an existing roof.