Low-slope roofs depend on designed drainage even when they look flat from the ground. The covering, slope, drains, scuppers, and surrounding details work together. A new membrane alone does not resolve every drainage concern.
What to do next
Ask the contractor to explain where water is intended to travel and what defects were observed. Compare proposals on whether drainage corrections are included. Keep structural or design questions assigned to the appropriate professional rather than assuming the membrane installer alone resolves them.
Related Perkins guidance
Contact Perkins Roofing to discuss your roof and the appropriate next step.