The goal of this job is to re-roof, but also make the structure more energy efficient by adding ventilated overhanging soffit to the new eaves.
I need to accurately locate roof trusses below a roof deck with underlayment so I can screw down 2x4 sleepers set vertically on top of them. These sleepers will hang over, or extend past the outside wall 18" to create space for the ventilated soffit. I’m concerned if the sleepers is not exactly over the truss, the screws may glance off, pull out or split the existing truss. This home is in Iowa which is known straight line winds and tornado’s.
I doubt any stud finder would work accurately through 1/2" plywood and underlayment. Any suggestions?