Some waterproofing systems and roof finishes are tough; others are more delicate and not meant for heavy foot traffic with hard shoes. Grit stuck in soles, sharp heels or work boots can scuff, puncture or scratch membranes, especially when hot sun has softened them.
Asking workers and even residents to wear soft-soled shoes or slippers on such roofs reduces damage. It sounds fussy, but it’s like walking carefully on a new polished floor—you’re protecting an expensive layer that keeps your building dry.
Once damaged, tiny cuts may not leak immediately, but they become future entry points for water. Prevention really is easier here than repair.