Fixing Air Leakage in Exterior Rigid Foam on Roof Retrofit-Pics Included
I live in Norfolk, VA. 4A Climate zone. About 50 miles south and I will be in Climate zone 3. I live in a 100 year old home.
In the past year I decided to start on a multi year energy retrofit project. One of my first steps was the roof. Based on GBA recommendations, and due to low slope roof I decided on external rigid foam. I hired a consultant, and they put a great design together for me. However, finding a roofer to install was another matter. So the consultants design was not 100% what was able to be completed. Long story short, after the roof has been installed and I have blower door tested, there is still major air leakage from the attic to outside the home. It was difficult to make sure the roofers did the air sealing parts correctly. In their defense, this was probably their first time doing external rigid foam on a residential home, that was not an EPDM roof.
The gable ends are air tight, and the eves are air tight. These two sections I did myself. Also blower door + thermal shows this.
This leads me to believe there is leakage at the ridge beam and possibly through the board sheathing and into the underside of the zip.
Here is my solution. Is this crazy? Other ideas?
Add essentially a mini knee wall, then drywall the kneewall, and drywall the ceiling after I have added rockwool between the beams. The rest of my home is stripped down to new drywall. Have Aerobarrier come in and spray the house, and make the air barrier the drywall.
Will that space behind the kneewall with “hand stuff fiberglass” be a problem. Will it be able to dry?
Please let me know thoughts. Retrofits seem to encounter many more problems than one would expect.
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