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Community and Q&A

Baffles in shed roof addition

user-7764336 | Posted in General Questions on

Prior to buying our house, the owner had an addition added to the back of the home. It is a 1 story shed roof that butts into the original back of the house. I recently had a roof put on the entire home about 1-2 years ago and knew very little about this community/FHB. The contractor added open soffits and a Cora-vent strip near the top of the shed roof to allow for ventilation on the shed roof. This proves for a very leaky house since the cold or hot air can basically come directly into the soffit.

I was thinking on cutting poly-iso baffles and running them all the way up the truss to guide the air from the soffits channeling to the ventilation strip. I was going to attach the baffle to the truss with spray foam to help air seal as well. After the baffles are run, I would install rockwool or some sort of typical insulation in the joists.

Is this a worthwhile project that will keep the roof vented but help tighten up the house? I feel its the best chance I have at venting the shed roof and stopping it from channeling up the stud bays on the 2nd floor where the addition roof butts into the original house or falling down into the conditioned space.

Any help is appreciated!

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  1. Expert Member
    Michael Maines | | #1

    It's hard to fully understand your situation without photos or drawings, but I'm not sure why venting the underside of the roof sheathing would create a leaky house--it's standard practice on almost all new homes. Can you provide more information about what you have and why you think it's a problem?

    1. user-7764336 | | #2

      Yea 1000% - sorry. So the soffits are open but there is currently no baffle on the interior. I took down some drywall on the interior and I can reach over the top plate and into the exterior soffit which makes for an extremely leaky house. I was looking through the Renovation book (which is one of the pictures I've attached) so I'm assuming this is the correct way to do it. It is a shed roof though which butts into the original end of the home so I don't know if that "channels" the exterior air directly into the 2nd floor wall. I did have the roofer put a type of Cora-vent system under a course of shingles to help with ventilation. I'm assuming I would just turn the baffle up towards the roof sheathing to vent the soffit out of the vent since its a shed roof?

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