Removing old shingles creates an opportunity to evaluate the exposed substrate and plan the new underlayment assembly. The new outer covering should not hide unresolved decking or transition issues.
What to do next
Ask which inspection steps occur after removal and before new layers are installed. Agree on documentation and approval for concealed repairs. Keep the exact underlayment product and installation requirements in the scope rather than describing it only as felt or synthetic material.
Related Perkins guidance
Contact Perkins Roofing to discuss your roof and the appropriate next step.