Do you have a step flashing detail for gyproc sheathed 2nd story wall/garage roof interface?

Don Fraser
Updated: Dec. 5, 2021

I have a mid 70's house with exterior gyproc sheathing, and currently alluminum siding (second floor) that needs to be replaced. There appear to have been leaks along the step flashing wall to roof interface onto the garage gyprock cieling ( water has run down the rafter).  Step flashing needs to be nailed to something and of course, you can't nail to gyprock. I am planning to re-side with vinyl siding, with a tyvec type material covering and strapping to provide a breathing space between the cladding and the sheathing. I need a detail for the roof to wall interface for the step flashing that needs to be installed. I had not planned to install exterior insulation, but if I do, I need a detail for that. The issue to me for adding insulation to the exterior over a roof interferes with replacing roof sheathing in future, and my understanding that the current building code requires that you do not restrict  future maintnence requirements when you make modifications.

Would be please to hear from you!!

Responses (4)

Don Fraser 2 years ago

Can you not describe how to solve the step flashing issue in words without having a section detail?

Emmanuel B. Cosgrove 2 years ago

Hi Don, 

Have you considered trying to attach it with an adhesive? I wonder if that wouldn't work as it would then be under the siding, and how are you going to install the siding on top without backing? I don't want to leave you hanging, but its difficult to visualize without being there and I wonder if the best advice I can give you is actually how to find advice elsewhere, rather than us bounce ideas back and forth with you trying to help me visualize this. Have you tried doing a Google search for step flashing diagram and click 'image' ? You may actually see something that will get you going way faster than we can.

Alternatively, it sounds like you are planning to do this work yourself, what about hiring an experienced local roofer for an hour of guidance? I would hate to steer you wrong because I cant be there beside you looking at it and given that this is roof leak you are fixing, the stakes are too high to mess it up.

Proper roofing and flashing installation to prevent leaks should really take into account local weather variables like the typical snow load (if you get any), prevailing wind direction, stuff that we just don't know. Thoughts?