A multi-layer panel for use as structural sheathing with a coating that is both fire resistant and water resistant. The multi-layer panel may be a wood structural panel, such as OSB or plywood. The coating provides building-code-compliant fire resistance characteristics. The coating also acts as a water resistant barrier (WRB) layer on a surface of the panel. The joint fire-resistant and water-resistant barrier (FR/WRB) coating may be applied to one or both faces of the panel at the manufacturing facility, prior to shipping or installation at a job site. The coating may also be applied to panel edges.