Overroof venting, aka a weird intersection of roofs…
Hey all, I’m building a home in the foothills of the Cascade mountains in WA. It’s listed as Zone 4, but it gets some snow, is on the edge of a rain forest that gives us very wet winters and very dry summers.
The house has two 20′ wide roof sections that intersect at a T. One is vaulted and vented using the I-joist method similar to last year’s Fine Homebuilding project house. The other roof is a more conventional raised heel truss roof. Ridge vents for both.
The conundrum I’m getting lost in is how to detail the ventilation for the little roof section that extends from the vaulted roof line over the truss roof where they intersect.
The vaulted roof will have a ridge vent. That can easily extend over the intersection to where it meets the truss roof section. But the question I still have is how to get air in there? I can cut some slots in the plywood of the truss roof similar to soffit intakes to let air in, but I wonder if that’s going to mess up the ventilation for the truss roof section. Also because of the width of the vaulted roof section and the length of the truss roof section, the truss roof section is really only pulling air in from one side.
The other possibility is that I’m worrying over nothing and that a roof built on top of a roof doesn’t need any venting at all and that the truss side will be just fine with only pulling air in from one side.
Thanks in advance for any insights!