How is a metal roof installed?

A metal roof goes on over a clean, sound deck. The crew installs an underlayment (often a high-temperature synthetic or self-adhering membrane), then sets the panels from the eave upward, fastening either through the face (exposed-fastener panels) or with concealed clips (standing seam). Trim, ridge caps, and flashing at penetrations finish the system.

Standing-seam is the more weather-resistant and more expensive method because the fasteners are hidden and the panels can expand and contract without loosening screws. Exposed-fastener metal is cheaper and faster but the gaskets need eventual attention.

Metal roofing is unforgiving of poor flashing and measurement, so it is generally a job for an experienced installer rather than DIY.